PAES 421:2009 Farm to Market Roads PDF

PAES 421:2009 PHILIPPINE AGRICULTURAL ENGINEERING STANDARDS Farm to Market Roads (Earth, Gravel, Bituminous, Concrete) Foreword The pursuance of this standard was initiated by the National Agricultural and Fishery Council (NAFC) through the Agriculture and Fisheries Mechani...

PAES 421:2009 PHILIPPINE AGRICULTURAL ENGINEERING STANDARDS Farm to Market Roads (Earth, Gravel, Bituminous, Concrete) Foreword The pursuance of this standard was initiated by the National Agricultural and Fishery Council (NAFC) through the Agriculture and Fisheries Mechanization Committee (AFMeC). This standard has been technically prepared in accordance with BPS Directives Part 3:2003 – Rules for Structure and Drafting International Standards. The word “shall” is used to indicate mandatory requirements to conform to the standard. The term “should” is used to indicate that among several possibilities one is recommended as particularly suitable without mentioning or excluding others. The word “road carriageway” shall be used to indicate a portion of a roadway intended for the use of vehicles except the shoulder. However, words such as “traffic lanes” and “traveled way” indicate the same meaning stated for roadway carriage. In the preparation of this standard, the following documents/publications were considered; Agrarian Reform Infrastructure Support Project Phase II (ARISP-II) Implementation Manual on Farm-to-Market Roads Development (DAR-ARISP, Volume IV), July 2002 Department of Public Works and Highways (DPWH) Standard Specifications for Highways, Bridges and Airports, Volume II, 1995 and 2004 versions. ISO : USAF Landscape Design 18:5 Erosion Control Measures ISO : DelDOT Road Design Manual : Cross- Section elements : 2004 ISO : ARRB Transport Research : Environmental Best Practices – Outback Roads ISO : Nashua, New Hampshire Board of Public Works: Standard Specifications for Road Construction: June 1986 ISO : US Department of Transportation- Report No. FWA-LT- 01-002: Dust Control on low Volume Roads: May 2001 ISO : Thorndike, Maine: Thorndike, Maine road Ordinance ISO : TxDOT Glossary ISO : NCDFR – Access Road Construction : Design Guidelines 1  PAES 421:2009 1. Scope This standard specifies the minimum requirements for the design and construction of one-lane and two lane earth, gravel, bituminous and concrete farm-to-market roads for use in the preparation of program of works. It includes related structures such as drainage (roadside ditch and culvert), slope protection and erosion control. 2. References The following normative documents contain provisions through which reference in this text constitute provisions of this National Standard: Agrarian Reform Infrastructure Project Phase II (ARISP-II); Implementation Manual on Farm-to-Market Roads Development, Volume IV Infrastructure for Rural Productivity Enhancement Sector (INFRES) Project National Irrigation Administration (NIA) FMR Project Department of Public Works and Highways (DPWH), Standard Specifications for Highways, Bridges, and Airports, Volume II, 2004. ISO : USAF Landscape Design 18:5 Erosion Control Measures ISO : DelDOT Road Design Manual : Cross- Section elements : 2004 ISO : ARRB Transport Research : Environmental Best Practices – Outback Roads ISO : Nashua, New Hampshire Board of Public Works: Standard Specifications for Road Construction: June 1986 ISO : US Department of Transportation- Report No. FWA-LT- 01-002: Dust Control on low Volume Roads: May 2001 ISO : Thorndike, Maine: Thorndike, Maine Road Ordinance ISO : TxDOT Glossary ISO : NCDFR – Access Road Construction : Design Guidelines 3. General Objective: This standard aims to formulate minimum requirements for the design and construction of Earth, Gravel, Bituminous and Concrete Farm-to-Market Roads. 3.1 Specifically, this standard aims to: 3.1.1 Formulate minimum requirements on the design and construction of one- lane or two-lane road which is composed of road carriageway and road shoulder; 2  PAES 421:2009 3.1.2 Formulate minimum requirements for drainage structures (ditches). 4. Definition of Terms For the purpose of this standard, the following definitions shall apply: 4.1 aggregates granular material of mineral composition such as sand, gravel, shell, crushed and uncrushed stone or light weight materials 4.2 backfill the suitable material used to replace other materials removed during construction 4.3 base course the layer of aggregate, soil-treated aggregate, treated soil, or soil aggregate that rests upon the Subbase or if no Subbase, upon the sub-grade. Treatment may include application of chemical-based soil additives such as soil-stabilizers and/or any approved method 4.4 borrow the suitable material used for embankments 4.5 bridge structure, including supports, erected over a depression or an obstruction, such as water, a highway, or a railway; having a roadway or track for carrying traffic or other moving loads; and having an opening measured along the center of the roadway between faces of abutments, spring lines of arches, or extreme ends of the opening for multiple box culverts or multiple pipes that are 60 inches or more in diameter and that have a clear distance between openings of not less than half of the smallest pipe diameter 4.6 clearing removal and disposal of trees, vegetation or other unwanted materials from the ground surface 4.7 compaction application of pressure to aggregates to result in a dense mass free of excessive voids. Compaction minimizes settlement, decreases permeability and increases strength 4.8 course structural component of specified thickness. It may consist of one layer or more 4.9 culvert drainage structure that may or may not, directly support and that extends across and beneath a highway street, driveway, alley, arterial, or other public way 3  PAES 421:2009 4.10 crushed gravel product resulting from the mechanical crushing of gravel, with substantially all fragments having at least one face resulting from fracture 4.11 drainage removal of water from the road area by the use of culverts, ditches, channels and other several structures 4.12 earthwork operations connected with excavating and placing embankments with soil, earth or rock 4.13 erosion control protection of soil from disclosing by water, wind, or other agent 4.14 excavation act of cutting, digging, or scooping to remove material. 4.15 field density test determination of the degree of compactness of the soil 4.16 fill the embankment material placed above natural ground line 4.17 farm to market roads access roads that connect major road arteries to the agricultural production areas where farm produce are being mobilized and transported to the market by the farmers and fishermen 4.18 grade slope of a roadway, channel, or natural ground 4.19 gradation property of a soil which describes the distribution of size groups 4.20 gradient rate of increase or decrease in the level of the land, the slope expressed in percentage 4.21 grading preparation of the sub-grade, in line and elevation, for application of pavement materials including base and surfacing materials 4.22 grubbing removal and disposal of trees, and other unwanted materials below the ground surface 4  PAES 421:2009 4.23 lane roadway roadway, which is divided into two (2) or more clearly marked lanes for vehicular traffic 4.24 masonry form of stone, brick, concrete block, concrete, or other similar building materials that have been bonded together with mortar to form a structure 4.25 one-lane earth road earth roadway, which one way is a clearly marked lane for vehicular traffic 4.26 one-lane gravel road gravel roadway, which one way is clearly marked lane for vehicular traffic 4.27 one-lane asphalt pavement road asphalt pavement roadway, which one way is clearly marked lane for vehicular traffic 4.28 one-lane concrete road concrete roadway, which one way is clearly marked lane for vehicular traffic 4.29 riprap quarried stone especially selected, graded and placed to prevent erosion and thereby preserve the shape of a surface, slope, or underlying structure 4.30 road bed graded portion of a highway between top and side slopes, prepared as a foundation for the pavement structure and shoulder 4.31 roadway space/location/site intended to employ traffic consideration for the transport of agricultural products 4.32 road carriageway travel way or crown portion of the roadway intended for the movement of vehicles, exclusive of shoulders 4.33 road carriageway width lateral design width for one lane or two lanes strip of roadway 4.34 roadway embankment raised structure of soil, soil aggregate, sand or rock 4.35 road shoulder part of the roadway next to the traveled way or auxiliary lanes that provide lateral support of base and surface courses and is an emergency stopping area for vehicles 5  PAES 421:2009 4.36 salvage materials saving of different existing materials from the projects which are removed and intended to be used in other construction 4.37 specifications written technical description of materials, equipment, construction systems, standards, and workmanship that, in conjunction with the drawings, detail the requirements for acceptable completion of the work 4.38 structures refer to the bridges, culverts, wall, buildings, foundations, water tanks, transmission towers, cribbing, caissons or coffer dams, other similar features which may be encountered in the work and are classified as structures 4.39 Subbase course refers to the layer of the specified or selected materials of designated thickness in a pavement structure immediately above the sub-grade and below the base course 4.40 subgrade (earth road) roadbed upon which the pavement structures is placed 4.41 subgrade (gravel road) upper portion of material which act as foundation Subbase course 4.42 subgrade (bituminous, concrete road) top surface of the roadbed upon which the pavement is placed 4.43 traffic vehicular and non-vehicular movement along a route such as pedestrians, vehicles, animals, etc. 4.44 two-lane earth road earth roadway, which two(2) ways are marked lanes for vehicular traffic 4.45 two-lane gravel road gravel roadway, which two (2) ways are marked lanes for vehicular traffic 4.46 two-lane asphalt pavement road asphalt pavement roadway, which two ways are marked lanes for vehicular traffic 4.47 two-lane concrete pavement road concrete pavement roadway, on which two lanes are marked for vehicular traffic 4.48 turn-out section a widened, unobstructed shoulder area, about 30 meters long, that may be used for emergency purposes or allow slow-moving vehicles to pull out of the carriageway to give passing opportunity to following or incoming vehicles 6  PAES 421:2009 5. TYPICAL LOCATION OF FARM-TO-MARKET ROADS 5.1 Roads shall conform to the land use plan of the area. 5.2 Roads shall link or be located in the key production areas of valuable crops such as rice, corn, and other high value commercial crops, livestock and fisheries. 5.3 Roads shall be of service to mobilize agricultural products/produce from the production areas to the nearest existing roadway systems (e.g. barangay, municipal roads, etc.). Production Area Farm-to-Market Road Production Area Existing Road Fig. 1: Typical Location of Farm-to-Market Road 6. DESIGN CONSIDERATIONS FOR: Earth Road Gravel Road Bituminous Road Concrete Road 6.1 The road shall provide space for the safety and comfortable movements of vehicles. 6.2 The road shall be designed to provide ease in transportation. It should not damage the produce during transport. 6.3 Road pavement material shall be generally stiffer than the material upon which it is placed, thus it assists the in situ material in resisting loads without excessive deformation or cracking. 7  PAES 421:2009 6.4 Road pavement material shall be constructed and maintained to be much smoother than in situ material. This improves riding comfort and reduces vehicle operation costs. 6.5 The road should be constructed on high elevation and avoid going through marshy and boggy areas. It shall not be located in swampy, logged-over and flooded areas. These areas that stay wet most of the time have a lower weight bearing capacity and have a greater probability of becoming a problem area in the future. 6.6 Steep slope shall be avoided. 6.7 Road shall not pass through fault lines. 6.8 Earthworks shall be minimal i.e. for sites requiring big volumes of excavation and embankments. 6.9 Road shall minimize environmental problems such as erosion, andslides and forest denudation. 6.10 Road shall provide adequate and efficient internal circulation within the development area. 6.11 Minimize road congestion and unsafe conditions. 6.12 Road shall be designed and arranged with appropriate regard for topography, creeks, wooded areas and other natural features which would enhance attractive development. 7. ROADWAY 7.1 ONE-LANE ROADWAY Earth Road Gravel Road Bituminous Road Concrete Road There shall be provisions of turn-out (around 1-2 m wide and 30 m long) on strategic locations for maneuver of two (2) vehicles traveling in opposite directions. A turn-out of about 1-2 meter wide and 30 meters long should be provided in critical sections especially on steep grades along mountainous areas. Ex. If two (2) vehicles are traveling in opposite directions, each vehicle shall deviate from the lane taking the shoulder in order to give way for the other vehicle to pass. 8  PAES 421:2009 1M 2M 1M Figure 2 The roadway width shall be 4 meters (including shoulders). There should be provisions of super elevations on curved sections of the road to minimize accidents. The angle of intersection. It is preferred that the proposed roadway intersects the existing road at right angles (90 degrees). But the intersecting angles in the range of 45 – 60 degrees are acceptable. Intersection angles of 45 – 60 degrees may be used in special situations. Intersection angles less than 45 degrees are strongly discouraged. 7.2 ROAD CARRIAGEWAY Earth Road Gravel Road Bituminous Road Concrete Road The road carriageway shall provide space for the safety and comfort movement of the vehicles. The road carriageway width shall be a minimum of two (2) meters for one-lane roadway and four (4) meters for two-lane roadway. Road carriageway width shall be measured from the edge of the roadway shoulder to the opposite side of the edge of the roadway shoulder. The slope of the carriageway shall reduce seepage and erosion. For earth, gravel and bituminous roads, the minimum slope shall be 3% from the center line towards the ditch. This will promote rapid runoff of surface water and minimize the amount of water which infiltrates into the roadway. 9  PAES 421:2009 For concrete, the maximum slope shall be 1.5% from the center line towards the ditch. This will promote rapid run-off of surface water and minimize the amount of water which infiltrates into the road carriageway. For earth, gravel and bituminous roads, the road carriageway shall be constructed with aggregate Subbase course. For concrete, the road carriageway shall be constructed with aggregate base course. 7.3 ROAD SHOULDER Earth Road Gravel Road Bituminous Road Concrete Road The shoulder provides space for stopping outside of the traffic lanes, avoiding potential accidents or reduces their severity. It shall also provide space for lateral clearance to roadside facilities such as guardrail and pedestrian use. The shoulder shall provide structural support for the road carriageway. The shoulder shall reduce seepage adjacent to the carriageway by discharging storm water towards the ditch. The shoulder should provide space for occasional motorists who have to stop to consult road maps, to rest, or for other emergency reasons. The shoulder should provide space for pedestrian and bicycle use. The minimum road shoulder width shall be 1.0 meter. It should be filled with borrow and compacted to at least 95% density, as certified by accredited laboratory. For concrete road, the minimum road shoulder width shall be 1.0 m. It should be Subbase compacted to the required density. The maximum slope of road shoulder shall be 4% from the edge of the road carriageway. 10  PAES 421:2009 ℄ 1.0 2.0 1.0 3.0% 3.0% 4.0% 4.0% Aggregate Subbase Course Road Side Ditch Road Side Ditch Borrow Natural Ground Line Borrow Shoulder Shoulder Figure 3 – Typical Cross Section of One-Lane Earth Road ℄ 1.0 2.0 1.0 0.3 0.3 3.0% 3.0% 4.0% 4.0% Aggregate Surface Course Road Side Ditch Aggregate Subbase Course Road Side Ditch Borrow Borrow Natural Ground Line Shoulder Shoulder Figure 4 - Typical Cross Section of One-Lane Gravel Road 11  PAES 421:2009 ℄ 1.0 2.0 1.0 0.3 0.3 3.0% 2.50% 3.0% Bituminous Pavement Aggregate Base Course Road Side Ditch Aggregate Subbase Course Road Side Ditch Borrow Borrow Shoulder Shoulder Figure 5 - Typical Cross Section of One-Lane Bituminous Pavement ℄ 1.0 2.0 1.0 0.3 0.3 1.5% 3.0% 3.0% Concrete Pavement Road Side Ditch Aggregate Road Side Ditch Subbase Course Subbase Subbase Shoulder Shoulder Figure 6 - Typical Cross-Section of One Lane Concrete Road 12  PAES 421:2009 7.4 SITE OF ROAD EXPANSION FOR ONE-LANE ROAD Earth Road Gravel Road Bituminous Road Concrete Road The road shall be constructed either left or right from the center or the existing Right of Way (ROW) in order to accommodate expansion in the future. The design of the roadside ditch within the Right of Way (ROW) should be earth ditch, since it will be damaged during expansion. However, steep slope ditch should be constructed of other materials to prevent erosion. ℄ 2.0 1.0 2.0 1.0 Site for Road Expansion Aggregate Subbase Course Road Side Ditch Road Side Ditch Natural Ground Line Figure 7 - Typical Site of Earth Road for Expansion ℄ 2.0 1.0 2.0 1.0 Proposed Site for Road Expansion Aggregate Base Course Road Side Ditch Aggregate Subbase Road Side Ditch Fig. 8 Typical Cross-section of one-lane gravel road for expansion 13  PAES 421:2009 ℄ 2.0 1.0 2.0 1.0 Proposed Site for Bituminous Pavement Road Expansion Aggregate Base Course Road Side Ditch Aggregate Subbase Course Road Side Ditch Figure 9 - Typical Position of Bituminous Road for Stage Development ℄ 2.0 1.0 2.0 1.0 Proposed Site for Road Expansion Aggregate Base Course Road Side Ditch Aggregate Subbase Course Road Side Ditch Figure 10 - Typical Site of One-Lane Concrete Road for Expansion 14  PAES 421:2009 ℄ 1.0 0.3 2.0 2.0 0.3 1.0 3.0% 3.0% 4.0% 4.0% Aggregate Subbase Course Road Side Ditch Natural Ground Line Road Side Ditch Borrow Borrow Road Shoulder Road Shoulder Figure 11 - Typical Cross-Section of a Two-Lane Earth Road ℄ 1.0 2.0 2.0 1.0 0.3 0.3 3.0% 3.0% 4.0% 4.0% Aggregate Base Course Road Side Ditch Aggregate Subbase Road Side Ditch Borrow Borrow Road Shoulder Road Shoulder Figure 12 - Typical Cross-Section of Two-Lane Gravel Road 15  PAES 421:2009 ℄ 1.0 2.0 2.0 1.0 0.3 0.3 3.0% 3.0% 4.0% 4.0% Bituminous Pavement Aggregate Base Course Road Side Ditch Road Side Ditch Aggregate Subbase Course Borrow Borrow Shoulder Shoulder Figure 13 – Typical-Cross-Section of Two-Lane Bituminous Road ℄ 1.0 2.0 2.0 1.0 3.0% 3.0% 4.0% 4.0% Concrete Pavement Road Side Ditch Road Side Ditch Subbase Aggregate Subbase Course Subbase Shoulder Shoulder Figure 14 -Typical Cross-Section of a Two-Lane Concrete Road 16  PAES 421:2009 7.5 Roadway on Lateral and Sub Lateral Irrigation Canals In lateral and sub-lateral canal where the available roadway width is 3 meters, the carriageway width shall be 2 meters and the shoulder width shall be 0.5 meters. If the available roadway width is 4 meters, the shoulder shall expand to 1 meter. 0.5 2.0 0.5 1.5 1.5 1.5 1.5 1 1 1 1 Figure 15 - Typical Cross-Section of Roads in Lateral and Sub-lateral Canal 7.6 Roadway on Main Irrigation Canals In canal (main) where the available roadway width is 6 meters, the carriageway width shall be 4 meters and the shoulder width shall be 1.0 meter. 1.0 4.0 1.0 1.5 1.5 1.5 1.5 1 1 1 1 Figure 16 - Typical Cross-Section of Roads in Main Canal 7.7 Structural Requirement Roadway pavement material shall be placed and maintained much smoother than insitu material. This helps improve riding comfort and reduces vehicle operation. Road pavement shall be generally stiffer than the material upon which it is placed, thus, it assists the insitu material in resisting loads without excessive deformation. Roadway shall convey storm water flow via road side ditch to predetermined roadway crossings. The centerline of the roadway shall be the highest point which slopes down to either side. This will promote rapid runoff of excess water and minimize the 17  PAES 421:2009 amount of water which infiltrate into the roadway soil. This also prevents ponding of water which results to weakening of the roadway base. Excessive embankment of roadway (more than one meter from the original ground surface) should not be designed without any justifiable reasons. The necessity of high roadway embankment, (for example, indicating flood level) should be technically explained in the design documents. If no reason can be cited, the recommended embankment height shall not exceed 50 cm. from the original ground. There shall be provisions to lessen the environmental impacts of road construction and should be specified in the erosion and sediment control plan including measures to ensure that the exposed working surface are kept to a minimum, and silt fences and sediment traps are optimally placed to prevent sediments from reaching drainage systems. 8. GEOMETRIC DESIGN 8.1 Design speed There shall be design speed provisions to lessen the occurrence of accidents due to over speeding. Radius of Curvature The minimum radius design for curvature shall be 500 meters for flat terrain, 150 meters for rolling terrain and 50 meters for mountainous terrain. Avoid minimum radius at the beginning and end of all straight sections with a length of more than 5 kilometers and or isolated curves. Curves with larger radius must be used where terrain permits. 8.2 Intersection Careful consideration shall be given to the intersecting roads. Longer sight distances should be required for larger and fast moving vehicles entering/traversing existing road. Trees shall be trimmed or cut as well as bushes, trees or other vegetation within the limit of the intersection area. The angle of intersection, if possible, shall be at right angles (90 degrees). However the intersecting angles in the range of 45–60 degrees are acceptable. Intersection at the angles of 45–60 degrees may be used in special situations. Intersections at angles of less than 45 degrees are strongly discouraged. Visibility shall range from 40 meters for roadway with a speed not exceeding 32 kph and 320 meters for roadway having 96 kph speed limit. 18  PAES 421:2009 8.3 Longitudinal Slope The maximum longitudinal slope shall be 10% for rolling and 12% for mountainous terrain with maximum length of 300 meters. 8.4 Side Slope The maximum side slope shall be 2:1. Normal slope shall be 4:1. Provide separate design slope for cut and fill. This depends on soil classification for cut and height of fill embankment. 8.5 Cross Fall The cross fall (crown) shall be 1.5 – 2.0% 9. CLEARING AND GRUBBING Earth Road Gravel Road Bituminous Road Concrete Road 9.1 Description This item shall consist of clearing, grubbing, removing and disposing all vegetation and debris as designated to remain in place or are to be removed in consonance with other provisions of this Specification. The work shall also include the preservation from injury or defacement of all objects designated to remain. 9.2 Construction Requirements Before the work starts, the Engineer shall establish the limits of work and designate all trees, shrubs, plants and other things to remain. The Contractor shall preserve all objects designated to remain. The contractor shall be allowed to remove only trees and brushes that are absolutely necessary for his construction operation. The contractor shall save as many trees as possible. Removal of all trees and brushes, including their stumps necessary for construction purposes, shall be done in such a manner to present a neat appearance at the end of the work. Paint required for cut or scarred surface of trees or shrubs selected for retention shall be an approved asphalt base paint prepared especially for tree surgery. All surface objects and all trees, stumps, roots and other protruding obstructions, not designated to remain, shall be cleared and/or grubbed, including mowing as required, except as provided below: 19  PAES 421:2009 Removal of undisturbed stumps and roots and nonperishable solid objects with a depth of 1 meter below sub-grade for slope of embankments will not be required. In areas outside the grading limits of cut and embankment areas, stumps and nonperishable solid objects shall be cut off not more than 150 mm (6 inches) above the ground line or low water level. In areas to be rounded at the top of cut slopes, stumps shall be cut off flush with or below the surface of the final slope line. Grubbing of pits, channel changes and ditches will be required only to a depth necessitated by the proposed excavation within such areas. Except in areas to be excavated, stumps, holes and other holes from which obstructions are removed shall be backfilled with suitable material and compacted to the required density. No burning is permitted unless otherwise done in accordance with applicable laws, ordinances and regulations. If burning is permitted, perishable materials shall be burned under the constant care of competent watchmen at such times and in such a manner that the surrounding vegetation, other adjacent property or anything designated to remain on the right of way will not be jeopardized. The Contractor shall use high intensity burning procedures, (i.e. incinerators, high stacking or pit and ditch burning with forced air supplements) that produce intense burning with little or no visible smoke emission during the burning process. At the conclusion of each burning session, the fire shall be completely extinguished so that no smoldering debris remains. In the event that the Contractor is directed by the Engineer not to start burning operations or to suspend such operations because of hazardous weather conditions, material to be burned which interfere with subsequent construction operations shall be moved by the Contractor to temporary locations clear of construction operations and later, if directed by the Engineer, shall be placed on a designated spot and burned. Materials and debris which cannot be burned and perishable materials may be disposed of by methods and at locations approved by the Engineer, on or of the project. No stumps, roots, brush or timber shall be buried within the limits of the roadway or within the limits of any lot to be dedicated for public purposes, or within the limits of any public easement. If disposal is burying, the debris shall be placed in layer with the material so distributed to avoid nesting. Each layer shall be covered or mixed with earth material by the land-fill method to fill all voids. 20  PAES 421:2009 The top layer of material buried shall be covered with at least 300 mm (12 inches) of earth or other approved material and shall be graded, shaped and compacted to present a pleasing appearance. If the disposal location is off the project, the Contractor shall make necessary arrangements with the property owners in writing for obtaining suitable disposal locations which are outside the limits of view from the project. The cost involved shall be included in the unit bid price. A copy of such agreement shall be furnished to the Engineer. The disposal areas shall be seeded, fertilized and mulched at the Contractor’s expense. Woody material may be disposed of by chipping. The wood chips may be used for mulch, slope erosion control or may be uniformly spread over the selected areas as directed by the Engineer. Wood chips used as mulch for slope erosion control shall have a maximum thickness of 12 mm (1/2 inch) and faces not exceeding 3900 mm2 (6 square inches) on any individual surface area. Wood chips not designated for use under other sections shall be over the designated areas in layers not to exceed 75 mm (3 inches) loose thickness. Diseased trees shall be buried or disposed of as directed by the Engineer. All merchantable timber in clearing area which has not been removed from the right of way prior to the beginning of construction shall become the property of the Contractor unless otherwise provided. Low hanging branches or unsightly branches on trees or shrubs designated to remain shall be trimmed as directed. Branches of trees extending over the roadbed shall be trimmed to give a clear height of 6 meters above the roadbed surface. All trimmings shall be done by skilled workmen and in accordance with good surgery practices. Timber cut inside the area staked for clearing shall be felled within the area to be cleared. Individual trees or stumps designated by the Engineer for removal and located in areas other than those established for clearing and grubbing and roadside cleanup shall be removed and disposed of as specified under (disposal) except trees removed shall be cut as nearly flush with the ground as practicable without removing stumps. 9.3 Method of Measurement Measurement shall use the following alternate methods: 1. Area Basis The work to be paid for shall be the number of hectares and fractions thereof acceptably cleared and grubbed within the limits indicated on the plans or as may be adjusted in the field staking by the Engineer. Areas not within the clearing and grubbing limits shown on the Plans or not staked for clearing and grubbing will not be measured for payment. 21  PAES 421:2009 2. Lump-sum basis When the Bill of Quantities contains a Clearing and Grubbing lump-sum item, no measurement of area will be made for such item. 3. Individual Unit Basis (Selective Clearing) The diameter of tree will be measured at the height of 1.4 meters above the ground. Trees less than 150 mm in diameter will not be measured for payment. When Bill of Quantities indicates measurement of tree by individual unit basis, the units will be designated and measured in accordance with the following schedule of sizes in Table 1 Table 1 Diameter at height of 1.4 meter Pay Item Designation Over 150 mm to 900 mm Small Over 900 mm Large 9.4 Basis of Payment The accepted quantities, measured as prescribed in (Method of measurement) shall be paid for at the contract unit price for each of the Pay Items listed below that is included in the Bill of Quantities, which price and payment shall be full compensation for furnishing all labor, equipment, tools and incidentals necessary to complete the work prescribed in this Item. Payment shall be made under the following Table 2: Table 2 Pay Item Number Description Unit Measurement 100 (1) Clearing and Grubbing Hectare 100 (2) Clearing and Grubbing Lump Sum 100 (3) Individual Removal of Tress, Small Each 100 (4) Individual Removal of Trees, Large Each 10. EXCAVATION Earth Road Gravel Road Bituminous Road Concrete Road 22  PAES 421:2009 10.1 Description This Item shall consist of roadway and borrow excavation, and the disposal of materials in accordance with the Specifications and in conformity with the lines, grades and dimensions shown on the Plans or established by the Engineer. 10.1.1 Roadway Excavation Roadway excavation shall include excavation and grading for roadways, intersections, approaches, slope rounding, benching, waterways and ditches; removal of unsuitable materials from the roadbed and beneath embankment areas; and excavating selected materials found in the roadway as ordered by the Engineer for specific use in the improvement. Roadway excavation shall be classified as follows and as indicated in the Bill of Quantities. (1) Unclassified Excavation It shall consist of the excavation and disposal of all materials regardless of its nature, not classified and included in the Bill of Quantities under other pay items. (2) Rock Excavation It shall consist of igneous, sedimentary and metamorphic rocks which cannot be excavated without blasting or the use of rippers, and all boulders or other detached stones each having a volume of one (1) cubic meter or more as determined by physical measurements or visually by the Engineer. (3) Common Excavation It shall consist of all excavations not included in the Bill of Quantities under “rock excavation” or other pay items. (4) Muck Excavation It shall consist of the removal and disposal of deposits of saturated or unsaturated mixtures of soils and organic matter not suitable for foundation material regardless of the moisture content. 10.1.2 Borrow Excavation It shall consist of the excavation and utilization of approved material required for the construction of embankment as for other portions of the work, and shall be obtained from approved sources, in accordance with the following: (1) Case I Consists of materials obtained from sources designated on the Plans or in the Special Provisions. (2) Case II Consists of materials obtained from sources provided by the Contractor. 23  PAES 421:2009 10.2 Construction Requirements 10.2.1 General When there is evidence of discrepancies between the actual elevations and that shown on the Plans, a pre-construction survey referred to the datum plane used in the approved Plan shall be undertaken by the Contractor under the control of the Engineer to serve as the basis for the computation of the actual volume of the excavated materials. All excavations shall be finished to reasonably smooth and uniform surfaces. No materials shall be wasted without authority of the Engineer. No excavation operation shall be conducted so that material outside of the limits of the slope will not be disturbed. Prior to excavation, all necessary clearing and grubbing in that area shall have been performed in accordance with the requirements of Clearing and Grubbing. 10.2.2 Conservation of Topsoil Where provided for on the Plans or in the Special Provisions, all suitable topsoil encountered in excavation and on areas where embankments is to be placed shall be removed to such extent and to such depth as the Engineer may direct. The removed topsoil shall be transported and deposited in storage piles at locations approved by the Engineer. The topsoil shall be completely removed to the required depth from any designated area prior to the beginning of regular excavation or embankment work in the area and shall be kept separate from other excavated materials for later use. 10.2.3 Utilization of the Excavated Material All suitable materials removed from the excavation shall be used in the formation of embankment, sub-grade, shoulders, slopes, bedding and backfill for structures. All unsuitable materials shall be disposed of as shown on the plans or as directed by the Engineer. The Engineer will designate as unsuitable soil that cannot be properly compacted in the embankments. All unsuitable materials shall be disposed off as shown in the Plans or as directed without delay to the Contractor. Only approved materials shall be used in the construction of embankments and backfills. All unsuitable materials shall be disposed off as shown on the Plans or as directed by the Engineer. All excess material, including rocks and boulders that cannot be used in embankments shall be disposed off as directed. Material encountered in the excavation and determined by the Engineer as suitable for topping, road finishing, slope protection, or other purposes shall be conserved and utilized as directed by the Engineer. 24  PAES 421:2009 Borrow excavation shall not be placed until after the readily accessible roadway excavation has been placed in the fill, unless otherwise permitted or directed by the Engineer. If the Contractor places more borrow than is required and thereby causes a waste of excavation, the amount of such waste shall be deducted from the borrow volume. 10.2.4 Pre-watering Excavation areas and borrow pits may be pre-watered before excavating the material. When pre-watering is used, the areas to be excavated shall be moistened to the full depth, from the surface to the bottom of excavation. The water shall be controlled so that the excavated material will contain the proper moisture to permit compaction to the specified density with the use of standard compacting equipment. Prewatering shall be supplemented when necessary, by truck watering units, to ensure that the embankment contains the proper moisture at the time of compaction. The Contractor shall provide drilling equipment capable of suitably checking the moisture penetration to the full depth of the excavation. 10.2.5 Presplitting Unless otherwise provided in the Contract, rock excavation which requires drilling and shooting shall be presplit. Presplitting to obtain faces in the rock and shale formations shall be performed by the following methods: (1) Drilling holes at uniform intervals along the slope lines, (2) Loading and stemming the holes with appropriate explosives and stemming material (3) Detonating the holes simultaneously. Prior to starting drilling operations for presplitting, the Contractor shall furnish the Engineer a plan outlining the position of all drill holes, depth of drilling, type of explosives to be used, loading pattern and sequence of firing. The drilling and blasting plan is for record purposes only and will not absolve the Contractor of his responsibility for using proper drilling and blasting procedures. Controlled blasting shall begin with a short test section of the length approved by the Engineer. The test section shall be presplit, production drilled and blasted and sufficient material excavated whereby the Engineer can determine if the Contractor’s method are satisfactory. The Engineer may order discontinuance of the presplitting when he determines that the materials encountered have become unsuitable for being presplit. 25  PAES 421:2009 The holes shall be charged with explosives of the size, kind, strength, and at the spacing suitable for the formations being presplit, and with stemming material which passes a 9.5 mm (3/8 inch) standard sieve and which has the qualities for proper confinement of the explosives. The finished presplit slope shall be reasonably uniform and free of loose rock. Variance from the true plane on the excavated back slope shall not exceed 300 mm (12 inches); however, localized irregularities or surface variations that do not constitute a safety hazard or an impairment to drainage courses or facilities will be permitted. A maximum offset of 600 mm (24 inches) will be permitted for construction working bench at the bottom of each lift for use in drilling the next lower presplitting pattern. 10.2.6 Excavation of Ditches, Gutters, etc. All materials excavated from side ditches and gutters, channel changes, irrigation ditches, inlet and outlet ditches, toe ditches, furrow ditches, and such other ditches as may be designated on the Plans or staked by the Engineer, shall be utilized as provided in Subsection 102.2.3. Ditches shall conform to the slope, grade, and shape of the required cross-section, with no projections of roots, stumps, rock or similar matter. The Contractor shall maintain and keep open and free from leaves, sticks and other debris all ditches dug by him until final acceptance of the work. Furrow ditches shall be formed by plowing a continuous furrow along the line staked by the Engineer. The ditches shall be cleaned out by hand shovel work, by ditcher, by some other suitable method, throwing all loose materials on the downhill side so that the bottom of the finished ditch shall be approximately 450 mm (18 inches) below the crest of the loose material piled on the down hill side Hand finish will not be required, but the low lines shall be in satisfactory shape to provide drainage without overflow. 10.2.7 Excavation of Roadbed Level Rock shall be excavated to a depth of 150 mm (6 inches) below subgrade within the limits of the roadbed, and the excavation backfilled with material designated on the Plans or approved by the Engineer and compacted to the required density. When excavation methods employed by the Contractor leave undrained pockets in the rock surface, the Contractor shall, at his own expense, properly drain such depressions or when permitted by the Engineer fill the depressions with approved impermeable material. Material below subgrade, other than solid rock shall be thoroughly scarified to a depth of 150 mm (6 inches) and the moisture content increased or reduced, as necessary, to bring materials throughout this 150 mm later to the moisture content suitable for maximum compaction. This layer shall then be compacted in accordance with the requirements of Compaction. 26  PAES 421:2009 10.2.8 Borrow Areas The Contractor shall notify the Engineer sufficiently in advance of opening any borrow areas so that cross-section elevations and measurements of the ground surface after stripping may be taken, and the borrow material can be tested before being used. Sufficient time for testing the borrow material shall be allowed. All borrow areas shall be bladed and left in such shape as to permit accurate measurements after excavation has been completed. The Contractor shall not excavate beyond the dimensions and elevations established, and no material shall be removed prior to the staking out and cross-sectioning of the site. The finished borrow areas shall be approximately true to line and grade established and specified and shall be finished. When necessary to remove fencing, the fencing shall be replaced in at least as good condition as in the original. The contractor shall be responsible for the confinement of livestock when portion of the fence is removed. 10.2.9 Removal of Unsuitable Materials Where the plans show the top portion of the roadbed to be selected topping, all unsuitable materials shall be excavated to the depth necessary for replacement of the selected topping to the required compacted thickness. Where excavation to the finished graded section results in a subgrade or slope of unsuitable soil, the Engineer may require the contractor to remove the unsuitable material and backfill to the finished graded section with approved material. The Contractor shall conduct his operations in such a way that the Engineer can take the necessary cross-sectional measurements before the backfill is placed. The excavation of muck shall be handled in a manner that will not permit the entrapment of muck within the backfill. The material used for backfilling up to the ground line or water level, whichever is higher, shall be rock or other suitable granular material selected from the roadway excavation, if available. If not available, suitable material shall be obtained from other approved sources. Unsuitable material removed shall be disposed of in designated areas shown on the plans or approved by the Engineer. 10.3 Method of Measurement The cost of excavation of material which is incorporated in the Works or in other areas of fill shall be deemed to be included in the Items of Work where the material is used. Measurement of Unsuitable or Surplus Material shall be the net volume in its original position. For measurement purposes, surplus suitable material shall be calculated as the difference between the net volume of suitable material required to be used in the 27  PAES 421:2009 embankment and the net volume of suitable material from excavation. Separate items shall be provided for common, unclassified and rock material. The Contractor shall be deemed to have included in the contract unit prices all cost of obtaining land for the disposal of unsuitable or surplus materials. 10.4 Basis of Payment The accepted quantities, measured as prescribed in the Method of Measurement shall be paid for the contract unit price for each of the Pay Items listed below that is included in the Bill of Quantities which price and payment shall be full compensation for the removal and disposal of excavated materials including all labor, equipment, tools and incidentals necessary to complete the work prescribed in this Item. Payment shall be made under the following Table 3: Table 3 Pay Item Description Unit of Measurement 102 (1) Unsuitable Excavation Cubic Meter 102 (2) Surplus Common Cubic Meter Excavation 102 (3) Surplus rock excavation Cubic Meter 102 (4) Surplus Unclassified Cubic Meter Excavation 11. EMBANKMENT Earth Road Gravel Road Bituminous Road Concrete Road 11.1 Description This item shall consist of the construction of embankment in accordance with this Specification and in conformity with the lines, grades and dimensions shown on the Plans or established by the Engineer. 11.2 Material Requirements Embankment shall be constructed of suitable materials, in consonance with the following definitions: 1. Suitable Material- Material which is acceptable in accordance with the contract and which can be compacted in the manner specified in this item. It can be common material or rock. 28  PAES 421:2009 Selected Borrow, for Topping- Soil of such gradation shows that all particles will pass a sieve with 75 mm (3 inches) square openings and not more than 15 percent of the mass will pass the 0.075 mm or 0.003 in. (No. 200) sieve, as determined by AASHTO T 11. The material shall have a plasticity index of not more than 6 as determined by AASHTO T 90 and liquid limit of not more than 30 as determined by AASHTO T 89 2. Unsuitable Material-Material other than suitable materials such as: detrimental quantities of organic material, such as grass, root and sewerage; highly organic soils as peat and muck; soils with liquid limit exceeding 80 and/or plasticity index exceeding 55; soils with a natural water content exceeding 100%; soils with very low natural density, 800 kg/m3 or lower; soils that cannot be properly compacted as determined by the Engineer. 11.3 Construction Requirements 11.3.1 General Prior to Construction of embankment, all necessary clearing and grubbing in the area shall have been performed in conformity with the requirements of Clearing and Grubbing. Embankment construction shall consist of constructing roadway embankments, including preparation of areas upon which they are to be placed; the construction of dikes within or adjacent to the roadway; the placing and compacting of approved materials within roadway areas where unsuitable material has been removed; and the placing and compacting of embankment materials in holes, pits, and other depressions within the roadway area. Embankments and backfill shall contain no muck, peat, sod, roots or other deleterious matter. Rocks, broken concrete or other solid, bulky materials shall not be placed in embankment areas where piling is to be placed or driven. Where shown on the Plans or directed by the engineer, the surface of the existing ground shall be compacted to a depth of 150 mm (6 inches) and the specified requirements of this item. Where provided on the Plans and Bill of Quantities, the top portions of the roadbed in both cuts and embankments, as indicated, shall consist of selected borrow for topping from excavations. 11.3.2 Methods of Construction When there is evidence of discrepancies on the actual elevations and as shown on the Plans, a pre-construction survey referred to the datum plane used in the approved Plan shall be undertaken by the Contractor under the control of the Engineer to serve as the basis for the computation of the actual volume of the embankment materials. 29  PAES 421:2009 When embankment is to be placed and compacted on hillsides, or when the new embankment is to be placed against existing embankments, or when embankment is built one-half width at a time, the existing slope that are steeper than 3:1 when measured at the right angles to the roadway shall be continuously benched over those areas as the work is brought up in layers. Benching will be the subject to the Engineer’s approval and shall be of sufficient width to permit placement of operation and compaction equipment. Each horizontal cut shall begin at the intersection of the original ground and the vertical sides of the previous cuts. Material thus excavated shall be placed and compacted along with the embankment material in accordance with the procedure described in this section. Unless shown otherwise on the Plans or Special Provisions, where an embankment of less than 1.2 meters (4 feet) is to be made, all sod and vegetable matter shall be removed from the surface upon which the embankment is to be placed, and the cleared surface shall be completely broken up by plowing, scarifying, or stepping to a minimum depth of 150 mm except as provided in the Construction Requirements of Excavation. This area shall then be compacted in conformity with the requirements of Compaction of Embankment. Sod not required to be removed shall be thoroughly disc harrowed or scarified before construction embankment. Wherever a compacted road surface containing granular materials lies within 900 mm (36 inches) of the sub-grade, such old road surface shall be scarified to a depth of at least 150 mm (6 inches) wherever directed by the engineer. This scarified material shall then be compacted as provided in conformity to the requirements of Compaction of Embankment. When shoulder excavation is specified, the roadway shoulders shall be excavated to the depth and width shown on the Plans. The shoulder material shall be removed without disturbing the adjacent existing base course material, and all excess excavated materials shall be disposed of in conformity with the requirements of Utilization of Excavated Material of Excavation. If necessary, the areas shall be compacted before being backfilled. Roadway embankment of earth material shall be placed in horizontal layers not exceeding 200 mm (8 inches), loose measurement, and shall be compacted as specified before the next layer is placed. Effective spreading equipment shall be used on each lift to obtain uniform thickness prior to compacting. As the compaction of each layer progresses, continuous leveling and manipulating will be required to assure uniform density. Water shall be added or removed, if necessary, in order to obtain the required density. Removal of water shall be accomplished through aeration by plowing, blading, discing or other methods satisfactory to the Engineer. Where embankment is to be constructed across low swampy ground that will not support the mass of trucks or other hauling equipment, the lower part of the fill may be constructed by dumping successive loads in a uniformly distributed layer of a thickness not greater than the necessary to support hauling equipment while placing subsequent layers. 30  PAES 421:2009 When excavated material contains more than 25 mass percent of rock larger than 150 mm in greatest diameter and cannot be placed in layers of the thickness prescribed without crushing, pulverizing or further breaking down in pieces resulting from execution methods, such materials may be placed on the embankment in layer not exceeding in thickness the appropriate average size of the larger rocks, but not greater than 600 mm (24 inches). Even though the thickness of layer is limited as provided above, the placing of individual rocks and boulders greater than 600 mm in diameter will be permitted provided that when placed, they do not exceed 1200 mm (48 inches) in height and provided they are carefully distributed, with the interstices filled with finer material to form a dense and compact mass. Each layer shall be leveled and smoothed with suitable leveling equipment and by distribution of spells and finer fragments of earth. Lifts of material containing more than 25 mass percent of rock larger than 150 mm in greatest dimension shall not be constructed above an elevation of 300 mm (12 inches) below the finished sub- grade. The balance of the embankment shall be composed of suitable material smoothed and placed in layers not exceeding 200 mm (8 inches) in loose thickness and compacted as specified for embankments. Dumping and rolling areas shall be kept separate, and no lift shall be covered by another until compaction complies with the requirements of Compaction of Embankments. Hauling and leveling equipment shall be so routed and distributed over each layer of the fill in such a manner as to make use of compaction effort afforded thereby and to minimize rutting and uneven compaction. 11.3.3 Compaction Earth Road Gravel Road Bituminous Road Concrete Road Compaction Trials Before commencing the formation of embankments, the Contractor shall submit in writing to the Engineer for approval his proposals for the compaction of each type of fill material to be used in the Works. The proposals shall include the relationship between the types of compaction equipment, and the number of passes required and the method of adjusting moisture content. The contractor shall carry out full scale compaction trials on areas not less than 10 meters wide and 50 meters long as required by the Engineer and using his proposed procedures or such amendments thereto as may be found necessary to satisfy the Engineer that all the specified requirements regarding compaction can be consistently achieved. Compaction trials with the main types of fill material to be used in the Works shall 31  PAES 421:2009 be completed before work with the corresponding materials will be allowed to commence. Throughout the periods when compaction of earthworks is in progress, the Contractor shall adhere to the procedures found from compaction trials for each type of material being compacted, each type of compaction equipment employed and each degree of compaction specified. Earth The contractor shall compact the material places in all embankment layer and the materials scarified to the designated depth below sub-grade in cut sections, until uniform density of not less than 95 mass percent of the maximum determined by AASHTO T 99 Method C, is attained, at a moisture content determined by Engineer to be suitable for such density acceptance of compaction may be based on adherence to an approved roller pattern developed in conformity with the requirements of Compaction Equipment and Density Control Strips, 1995 DPWH Standard Specification for Bridges and Airports, Volume II. The Engineer shall, during progress of the Work, make density tests of compacted material in accordance with AASHTO T 191, T 205, or other approved field density test, including the use of properly calibrated nuclear testing devices. A correction for coarse particles may be made in accordance with AASHTO T 224. If, by such test, the engineer determines that the specified density and moisture conditions have not been attained, the Contractor shall perform additional work as may be necessary to attain the specified conditions. At least one group of three in-situ density test shall be carried out for each 500 m2 of each layer of compacted fill. Rock Density requirements will not apply to portions of embankments constructed of materials which cannot be tested in accordance with approved methods. Embankment materials classified as rock shall be deposited, spread and leveled the full width of the fill with sufficient earth or other fine material so deposited to fill the interstices to produce a dense compact embankment. In addition, one of the rollers, vibrators or compactors meeting the requirements of Compaction Equipment and Density Control Strips, 1995 DPWH Standard Specification for Bridges and Airports, Volume II, shall compact the embankment full width with a minimum of three complete passes for each layer of embankment. 11.3.4 Protection of Roadbed During Construction During the construction of the roadway, the roadbed shall be maintained in such condition that will be well drained at all times. Side ditches and gutters emptying from cuts to embankments or otherwise, shall be constructed so as to avoid damage to embankments by erosion. 32  PAES 421:2009 11.3.5 Rounding and Warping Slopes Rounding-except in solid rocks, the tops and bottoms of all slopes, including the slope of drainage ditches, shall be rounded as indicated on the Plans. A layer of earth overlying rock shall be rounded above the rock as done in earth slopes. Warping- adjustments in slopes shall be made to avoid injury in standing trees or marring of weathered rock, or to harmonize with existing landscape features, and the transition to such adjusted slope shall be gradual. At intersections of cut and fills, slopes shall be adjusted and warped to flow into each other or into the natural ground surfaces without noticeable break. 11.3.6 Finishing Roadbed and Slopes After the roadbed has been substantially completed, the full width shall be conditioned by removing any soft or other unstable material that will not compact properly or serve the intended purpose. The resulting areas and all the other low sections, holes of depression shall be brought to grade with suitable material. Scarifying, blading, dragging, rolling or other methods of work shall be used as necessary to provide a thoroughly compacted roadbed shaped to the grades and cross-sections shown on the Plans or as directed by the Engineer. All earth slopes shall be left with rough surfaces but shall be reasonably uniform, without any noticeable break, and in reasonable close conformity with the Plans or other surfaces indicated on the Plans or as staked by the Engineer, with no variations wherefrom readily discernible as viewed from the road. 11.4 Method of Measurement The quantity of embankment to be paid shall be the volume of material compacted in place, accepted by the Engineer and formed with material obtained from any source. Material from excavation which is used in embankment and accepted by the Engineer will be paid under Embankment and such payment will be deemed to include the cost of excavating, hauling, stockpiling and all other incidentals to the work. Material for Selected Borrow topping will be measured and paid for under the same conditions specified in the preceding paragraph. 11.5 Basis of Payment The accepted quantities, measured as prescribed in the Method of Measurement shall be paid for at the Contract unit price for each of the Pay Items listed below that is included in the Bill of Quantities. The payment shall be full compensation for placing and compacting all materials including all labor, equipment tools and incidentals necessary to complete the work prescribed in this item. 33  PAES 421:2009 Payment shall be made as stated in the following Table 4: Table 4 Pay Item Number Description Unit of Measurement 104 (1) Embankment Cubic Meter 104(2) Selected, Borrow for Cubic Meter Topping, Case 1 104(3) Selected, Borrow for Cubic Meter topping, Case 2 12. SUBGRADE PREPARATION Earth Road Gravel Road Bituminous Road Gravel Road 12.1 Description This item shall consist of the preparation of the subgrade for the support of overlying structural layers. It shall extend to the full width of the roadway. Unless authorized by the engineer, subgrade preparation shall not be done unless the Contractor is able to start immediately the construction of the pavement structure. 12.2 Material Requirements Unless otherwise stated in the Contract and except when the subgrade is in rock cut, all materials below subgrade level to a depth 150 mm or to such greater depth as may be specified shall meet the requirements of Section 104.2, Selected Borrow for Topping. 12.3 Construction Requirements 12.3.1 Prior Works 12.3.2 Subgrade Level Tolerances The finished compacted surface of the subgrade shall conform to the allowable tolerances as specified hereunder: Permitted variation form + 20 mm Design LEVEL OF SURFACE -30 mm Permitted SURFACE IRREGULARITY MEASURED BY 3-m STRAIGHT EDGE 30 MM Permitted variation from design CROSSFALL OR CAMBER +0.5 % 34  PAES 421:2009 Permitted variation from Design LONGITUDINAL GRADE over 25 m length +0.1 % 12.3.3 Subgrade in Common Excavation Unless otherwise specified, all materials below subgrade level in earth cuts to a depth 150 mm or other depth shown on the Plans or as directed by the Engineer shall be excavated. The material, if suitable, shall be set aside for future use or if unsuitable, shall be disposed of in accordance with the requirements of Subsection 10.2.9 (Removal of Unsuitable Material). Where material has been removed from below subgrade level, the resulting surface shall be compacted to a depth of 150 mm and in accordance with other requirements of Subsection 11.3.3 (Compaction). All materials immediately below subgrade level in earth cuts to a depth of 150 mm, or to such greater depth as may be specified, shall be compacted in accordance with the requirements of Subsection 11.3.3. 12.3.4 Subgrade in Rock Excavation Surface irregularities under the subgrade level remaining after trimming the rock excavation shall be leveled by placing specified material and compacted to the requirements of Subsection 11.3.3. 12.3.5 Subgrade on Embankment After the embankment has been completed, the full width shall be conditioned by removing any soft or other unstable material that will not be compacted properly. The resulting areas and all other low sections, holes or depressions shall be brought to grade with suitable material. The entire roadbed shall be shaped and compacted to the requirements of Subsections 11.3.3. Scarifying, blading, dragging, rolling, or other methods of work shall be performed or used as necessary to provide a thoroughly compacted roadbed shaped to the cross- sections shown on the Plans. 12.3.6 Subgrade on Existing Pavement Where the new pavement is to be constructed immediately over an existing Portland Cement concrete pavement and if so specified in the Contract the slab be broken into pieces with greatest dimensions of not more than 500 mm and the existing pavement material compacted as specified in Subsection 11.3.3 as directed by the Engineer. The resulting subgrade level shall, as part pavement construction be shaped to conform to the allowable tolerances of Subsection 12.3.2 by placing and compacting where necessary a leveling course comprising the material of the pavement course to be placed immediately above. 35  PAES 421:2009 Where the new pavement is to be constructed immediately over an existing asphalt concrete pavement or gravel surface pavement or if so specified in the Contract, the pavement shall be scarified, thoroughly loosened, reshaped and re- compacted in accordance with Subsection 11.3.3 The resulting subgrade level shall conform to the allowable tolerances of Subsection 12.3.2 13. OVERHAUL Earth Road Gravel Road 13.1 Description Overhaul consists of authorized hauling in excess of the free-haul distance. Free- haul distance specifies distance that excavated material shall be hauled without additional compensation. Unless otherwise provided in the Contract, the free-haul distance shall be 600 meters. 13.2 Method of Measurement In determining what constitutes authorized overhaul, it will be assumed that material taken from excavation will be deposited in embankment after having been hauled the shortest distance. The overhaul distance for material obtained and placed within the roadway limit will be measured along the centerline of the roadway. No allowance will be made for transverse or lateral movement to or from the centerline except materials moved to or from designated areas outside the roadway limits; such as Case 1, Borrow Pits, disposal areas, etc. In such case, measurement shall be along the shortest route determined by the Engineer to be feasible and satisfactory unless otherwise provided. If the Contractor chooses to haul material over some other route, and such other route is longer, the computation for payment shall be based on the overhaul distance measured along the route designated by the Engineer. The number of cubic kilometers of overhaul to be paid for shall be the number of cubic meters of overhaul material multiplied by the overhaul distance in kilometers. The unit “cubic meter-kilometer” is the amount of hauling required to move one cubic meter a distance of one kilometer beyond the free-haul distance. 13.3 Basis of Payment The accepted quantities, measured as prescribed in the Method of Measurement shall be paid for the contract unit price for Overhaul, for the particular pay Item listed below that is shown in the bill of quantities, which price and payment shall be full compensation for overhaul, including all labor, equipment, tools and incidentals necessary to complete the work prescribed in this item. Payment will not be made for overhaul of Borrow, Case 2, Foundation Fill, bedding materials and materials removed in the rounding of cut slopes when rounding is a separate pay item. 36  PAES 421:2009 When the bill of quantities does not show estimated quantities for “Overhaul” from the Pay Item listed below, overhaul will not be directly paid for, but will be considered as a subsidiary obligation of the Contractor under other contract items. Payment shall be made under Table 5 Table 5 Payment Item Number Description Unit of Measurement 107 (1) Overhaul Cubic meter-kilometer 107(2) Overhaul of Borrow, Cubic meter-kilometer Case 1 14. AGGREGATE SUBBASE COURSE Earth Road Gravel Road Bituminous Road Concrete Road 14.1 Description This item shall consist of furnishing, placing and compacting an aggregate Subbase course on a prepared sub-grade in accordance with this Specification and the lines, grades and cross sections shown on the Plans, or as directed by the Engineer. 14.2 Material Requirements Aggregate for Subbase shall consist of hard, durable particles or fragments of crushed stone, crushed slag, or crushed or natural gravel and filler of natural or crushed sand or other finely divided mineral matter. The composite material shall be free from vegetable matters and lumps or balls of clay, and shall be such that it can be compacted to form a firm, stable Subbase. The Subbase material shall conform to Table 6, Grading Requirements Table 6 Sieve Designation Standard Alternate Mass Percent Passing mm US Standard 50 2” 100 25 1” 55-85 9.5 3/8” 40-75 0.075 No. 200 0-12 37  PAES 421:2009 The fraction passing the 0.075 mm (No. 200) shall not be greater than 0.66 (two thirds) of the fraction passing the 0.425 mm (No. 40) sieve. Plasticity The fraction passing the 0.425 mm (No. 40) sieve shall have a liquid limit not greater than 35 and plasticity index not greater than 12 as determined by AASHTO T 89 and T 90, respectively. Abrasion The coarse portion retained on a 2.00 mm (No. 10) sieve, shall have a mass percent of wear not exceeding 50 by the Los Angeles Abrasion Test as determined by AASHTO T 96. California Bearing Ratio (CBR) The material shall have a soaked CBR value of not less than twenty five percent (25%) as determined by AASHTO T 193. The CBR shall be obtained at the maximum dry density and determined by AASHTO T 180, Method D. 14.3 Construction Requirements 14.3.1 Preparation of Existing Surface The existing surface shall be graded and finished in conformity to the requirements of Subgrade Preparation, before placing the Subbase material. 14.3.2 Placing The aggregate Subbase material shall be placed as a uniform mixture on a prepared quantity that will provide the required compacted thickness. The placing of material shall begin at the point designated by the Engineer. Placing shall be from vehicles especially equipped to distribute the materials in a continuous uniform layer or windrow. The layer or windrow shall be of such size that when spread and compacted, the finished layer be in reasonably close conformity to the nominal thickness shown on the Plans. When the hauling is done over previously placed material, hauling equipment shall be dispersing uniformly over the entire surface of the previously constructed layer, to minimize rutting or uneven compaction. 14.3.3 Spreading and Compacting When uniformly mixed, the mixture shall be spread to the Plan thickness, for compaction. The maximum compacted thickness of one layer shall not exceed 150 mm. The moisture content of Subbase material shall, if necessary, be adjusted prior to compaction by watering with approved sprinklers mounted on trucks or by drying out, as required in order to obtain the required compaction. 38  PAES 421:2009 Immediately following final spreading and smoothening, each layer shall be compacted to the full width by means of approved compaction equipment. Rolling shall progress gradually from the side to the center, parallel to the centerline of the road and shall continue until the whole surface has been rolled. Any irregularities or depression that develop shall be corrected by loosening the material at these places and adding or removing material until the surface is smooth and uniform. If the layer of Subbase material, or part thereof, does not conform to the required finished, the Contractor shall, at his own expense, make the necessary corrections. Compaction of each layer shall continue until a field density of at least 100 percent of the maximum dry density determined in accordance with AASHTO T 180, Method D has been achieved. In-place density determination shall be made in accordance with AASHTO T 191. 14.3.4 Trial Section Before Subbase construction is started, the Contractor shall spread and compact trial sections as directed by the engineer. The purpose of the trial sections is to check the suitability of the materials and the efficiency of the equipment and construction method that is proposed and to be used by the contractor. Therefore, the Contractor must use the same material, equipment and procedures that he proposes to use for the main work. One trial section of about 500m2 shall be made for every type of material and/or construction equipment/procedure for use. After final compaction of each section, the Contractor shall carry out such field density tests and other test required as directed by the Engineer. If trial section shows the proposed materials, equipment or procedures in the engineer’s opinion are not suitable for Subbase, it shall be removed at the contractor’s expense, and a new trial section shall be constructed. If the basic conditions regarding the type of material or procedure change during the execution of the work, new trial sections shall be constructed. 14.3.5 Tolerances Aggregate Subbase shall be spread with equipment that will provide a uniform layer which when compacted will conform to the designated level and transverse slope as shown on the Plans. The allowable tolerances shall be specified hereunder: Permitted variation from design THICKNESS OF LAYER +20mm Permitted variation from design + 10mm LEVEL OF SURFACE - 20mm 39  PAES 421:2009 Permitted SURFACE IRREGULARITY MEASURED by 3-meter straight-edge -20 mm Permitted variation from design CROSSFALL OR CAMBER + 0.3% Permitted variation from design LONGITUDINAL GRADE over 25 meter length + 0.1% 14.4 Method of Measurement Aggregate Subbase course shall be measured in cubic meter (m3). The quantity to be paid for shall be the design volume compacted in-place as shown on the Plans, and accepted in the completed course. No allowance will be given for materials outside the design limits shown on the cross sections. Trial sections shall not be measured separately but shall be included in the quantity of aggregate Subbase herein measured. 14.5 Basis of Payment The accepted quantities, measured as prescribed in Section 14.4 shall be paid for at the contract unit price for aggregate Subbase course which price and payment shall be full compensation for furnishings and placing of materials, including all labor, equipment, tools and incidentals necessary to complete the work prescribed in this item. Payment will be made under Table 7: Table 7 Pay Item Number Description Unit Measurement 200 Aggregate Subbase Cubic meter Course 15. AGGREGATE BASE COURSE Gravel Road Bituminous Road Concrete Road 15.1 Description This item shall consist of furnishing, placing and compacting an aggregate base course on a prepared subgrade/Subbase in accordance with this Specification and the lines, grades and cross sections shown on the Plans, or as established directed by the Engineer. 40  PAES 421:2009 15.2 Material Requirements Aggregate for base course shall consist of hard, durable particles or fragments of crushed stone, crushed slag, or crushed or natural gravel and filler of natural or crushed sand or other finely divided mineral matter. The composite material shall be free from vegetable matter and lumps or balls of clay, such that it can be compacted to form a firm, stable base. In some areas where the conventional base course materials are scarce or unavailable, the use of 40% weathered limestone blended with 60% crushed stones or gravel shall be allowed, provided that the blended materials meet the requirements of this item. The base course material shall conform to Table 8 which ever is called for in the Bill of Quantities. Table 8. Grading Requirements Sieve Designation Mass Percent Passing Standard Alternate US Standard Grading Grading Mm A B 50 2” 100 37.5 1 ½” - 100 25.0 1” 60-85 - 19.0 ¾” - 60-85 12.5 ½” 35-65 - 4.75 No. 4 20-50 30-55 0.425 No.40 5-20 8-25 0.075 No. 200 0-12 2-14 The fraction passing the 0.075 mm (No. 200) sieve shall not be greater than 0.66 (two thirds) of the fraction passing the 0.425 mm (No.40) sieve. The fraction passing the 0.425 mm (No. 40) sieve shall have a liquid limit not greater than 25 and plasticity index not grater than 6 as determined by AASHTO T 89 and T 90, respectively. The coarse portion, retained on a 2.00 mm (No. 10) sieve shall have a mass percent of wear not exceeding 50 by the Los Angeles Abrasion test determined by AASHTO T 96. The material passing the 19 mm (3/4 inch) sieve shall have a soaked CBR value of not less than 80% as determined by AASHTO T 193. The CBR value shall be obtained at the maximum dry density (MDD) as determined by AASHTO T 180, Method D. If filler, in addition to that naturally present, is necessary for meeting the grading requirements or for satisfactory bonding, it shall be uniformly blended with the 41  PAES 421:2009 base coarse material on the road or in a pugmill unless otherwise specified or approved. Filler should be taken from sources approved by the Engineer, shall be free from hard lumps and shall not contain more than 15 percent of material retained on the 4.75 mm (No. 4) sieve. 15.3 Construction Requirements 15.3.1 Preparation of Existing Surface The existing Surface shall conform to the requirements of Subgrade Preparation. 15.3.2 Placing Placing shall be in accordance with all the requirements of Placing of Aggregate Subbase Course (Subsection 14.3.2). 15.3.3 Spreading and compacting It shall be in accordance with all the requirements of Spreading and Compacting, except that the field density required of each layer is not less than 100 percent of the maximum dry density determined in accordance with AASHTO T 180 Method D. The field density is determined in accordance with AASHTO T 191. 15.3.4 Trial Sections Trial Section shall conform to all the requirements specified in Subsection 14.3.4 (Trial Section of Aggregate Subbase Course). 15.3.5 Tolerances The aggregate base course shall be laid to the designed level and transverse slopes shown on the Plans. The allowable tolerances shall be in accordance with the following: Permitted variation from design THICKNESS OF LAYER + 10mm Permitted variation from design + 5mm LEVEL OF SURFACE -10mm Permitted SURFACE IRREGULARITY MEASURED by 3-meter straight-edge 5 mm Permitted variation from design CROSSFALL OR CAMBER + 0.2% Permitted variation from design LONGITUDINAL GRADE over 25 meter length + 0.1% 42  PAES 421:2009 15.4 Method of Measurement Aggregate base course shall be measured by cubic meter (m3). The quantity to be paid for shall be the design volume compacted in-place as shown on the Plans, and accepted in the completed course. No allowance will be given for materials outside the design limits shown on the cross sections. Trials shall not be measured separately but shall be included in the quantity of aggregate base herein measured. 15.5 Basis of Payment The accepted quantities, measured as prescribed in the Method of Measurement shall be paid for at the contract unit price for aggregate base course for which price and payment shall be full compensation for furnishings and placing of materials, including all labor, equipment, tools and incidentals necessary to complete the work prescribed in this item. Payment shall be made under: Table 9 Pay Item Number Description Unit Measurement 201 Aggregate Base Course Cubic meter 16. AGGREGATE SURFACE COURSE (0PTIONAL) Gravel Road 16.1 Description This item shall consist of a wearing or top course composed of gravel or crushed aggregate and binder material, whichever is called for in the Bill of Quantities, constructed on a prepared base in accordance with this Specification and in conformity with lines, grades and typical cross-sections shown on the Plans. 16.2 Material Requirements The aggregate base course shall consist of hard, durable particles or fragments of stone or gravel and sand or other fine mineral particles free from vegetable matter and lumps or balls of clay, and shall be such that it can be compacted to form a firm, stable layer. It shall conform to the grading requirements shown in Table 10. When tested by AASHTO T 11 AND T 27. 43  PAES 421:2009 Table 10 Sieve Designation Mass Percent Passing Standard Alternate US Grading Grading Grading Grading Mm Standard A B C D 25 1” 100 100 100 100 9.5 3/8” 50-85 60-100 - - 4.75 No. 4 35-65 50-85 55-100 70-100 2.00 No. 10 25-50 40-70 40-100 55-100 0.425 No. 40 15-30 25-45 20-50 30-70 0.075 No. 200 5-20 5-20 6-20 8-25 The coarse aggregate material retained on the 2.00 mm (No. 10) sieve shall have a mass percent of wear by the Los Angeles Test (AASHTO T 96) of not more than 45. When crushed aggregate is called for in the Bill of Quantities, not less than fifty (50) mass percent of the particles retained on the 4.75 mm (No. 40 sieve shall have at least one (1) fractured face. The fraction passing the 0.075 mm (No. 200) sieve shall not be greater than two- thirds of the fraction passing the 0.425 mm (No. 40) sieve. The fraction passing the 0.425 mm (No. 40) sieve shall have a liquid limit not greater than 35 and a plasticity index range of 4 to 9, when tested by AASHTO T 89 and T 90 respectively. Materials for gravel surface course and crushed aggregate surface course shall have a soaked CBR Value of not less than 25% and 80% respectively as determined by AASHTO T 193. The CBR Value shall be obtained at the maximum dry density and determined by AASHTO T 180, Method D. 16.3 Construction Requirements 16.3.1 Placing Aggregate Surface Course shall be placed in accordance with the requirements of Aggregate Base Course. 16.3.2 Compacting Requirements Aggregate surface course shall be compacted in accordance with the requirements on Aggregate Base Course 44  PAES 421:2009 16.3.3 Trial Sections Trial Sections shall be carried out in accordance with the requirements of Aggregate Base Course. 16.3.4 Surface Course Thickness and Tolerances The aggregate surface course shall be laid to the designed level and transverse slopes shown on the Plans. The allowable tolerances shall be as specified hereunder: Permitted variation from design +15mm THICKNESS OF LAYER -5mm Permitted variation from design +15mm LEVEL OF SURFACE -5mm Permitted SURFACE IRREGULARITY MEASURED by 3-meter straight-edge 5 mm Permitted variation from design CROSSFALL OR CAMBER +0.2% Permitted variation from design LONGITUDINAL GRADE over 25 meter length +0.1% 16.4 Method of Measurement Aggregate surface course shall be measured by the cubic meter (m3). The quantity to be paid for shall be the number of cubic meters of aggregate including all filler, placed, compacted and accepted in the completed course. No allowance will be given for material placed outside the design limits shown on the cross sections. Trial sections shall not be measured separately but shall be included in the quantity of aggregate base herein measured above. 16.5 Basis of Payment The accepted quantities, measured as prescribed in Method of Measurement shall be paid for at the contract unit price for Aggregate Surface Course for which price and payment shall be full compensation for furnishing, handling, placing, watering, and rolling all materials, including all labor, equipment, tools and incidentals necessary to complete the work prescribed in this item. 45  PAES 421:2009 Payment will be made under: Table 11 Pay Item Number Description Unit Measurement 300 Aggregate Surface Cubic meter compacted in Course place 300(1) Gravel Surface course Crushed Aggregate 300(2) Surface Course 17. BITUMINOUS PRIME COAT BITUMINOUS ROAD 17.1 Description This item shall consist of preparing and treating an aggregate course with material in accordance with the Plans and Specifications, preparatory to the construction of a bituminous surface course. 17.2 Material Requirements Bituminous material shall be either Rapid Curing (RC) or Medium curing (MC) Cut- back Asphalt, whichever is called for in the Bill of Quantities. It shall conform to the requirements of Item 702, Bituminous Materials, 1995 DPWH Standards Specifications for Bridges and Airports, Volume II. The type and grade shall be specified in the Special Provisions. 17.3 Construction Requirements 17.3.1 Surface Condition Prime coat shall be applied only to surfaces which are dry or slightly moist. No prime coat shall be applied when the weather is foggy or rainy. 17.3.2 Equipment The liquid bituminous material shall be sprayed by means of a pressure distributor of not less than 1000 liters capacity, mounted on pneumatic tires of such width and number tha