Highway Design Data - Existing Pavement Evaluation PDF
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Summary
This document provides detailed procedures for evaluating the condition of existing pavements, including asphalt and unpaved roads. The document explains methods for assessing road conditions and recording data for use in pavement management systems. Key topics include segmenting procedures, identifying road distress, and material quality assessment.
Full Transcript
CHAPTER 3: Highway Design Data Existing Pavement Evaluation THEORIES AND PROCEDURES ON VISUAL ROAD CONDITION (ROCOND) ASSESSMENT Road Condition (RoCond) Survey Objectives: Record, describe and measure the condition of the road at the time of rating Provide a sequence of rec...
CHAPTER 3: Highway Design Data Existing Pavement Evaluation THEORIES AND PROCEDURES ON VISUAL ROAD CONDITION (ROCOND) ASSESSMENT Road Condition (RoCond) Survey Objectives: Record, describe and measure the condition of the road at the time of rating Provide a sequence of recorded condition that can be analyzed to indicate performance trends Provide condition data for analysis in the Pavement Management System (PMS), Routine Maintenance Management System (RMMS), and eventually for budgeting in the Multi-Year Programming System (MYPS). Procedures in RoCond Assessment I. Survey Preparation Survey schedule and form a survey team. Survey instruments, survey forms, service vehicle, etc. Prepare survey gadgets, food and water. Survey Equipment: Measuring tools and Safety gears Service Vehicle Measuring Wheel/Measuring Crack Width Scale Tape Straight Edge, 1.2m long & Spray Paint (or other appropriate road Measuring Wedge Field Worksheets/pen or marking materials, e.g. Chalk, Charcoal) pencil Jackets/Long Sleeves Shirt Hats/Caps Rubber Shoes Safety devices for Traffic guide: Safety Vests Traffic Guidance Cones Appropriate Advance Warning Signs (Flags, Tarpaulin, etc…) Straight Edge and Measuring Wedge Procedures in RoCond Assessment II. RoCond Survey Activities a) Ensure the observance of proper road safety precaution, before and during the survey. Procedures in RoCond Assessment II. RoCond Survey Activities b) Establish RATING SEGMENTS along the entire road sections. c) Establish the GAUGING LENGTH for every rating segment created and mark every 100m distance thereafter within the segment. d) Mark the measured distances with paint along the edge of the pavement or other adjacent permanent references in increasing direction. These markings will be the basis of the conduct of surveys for the succeeding years to avoid re-measurement of distances and shorten the duration of survey. e) Start assessing, measuring and recording the distresses found along each segment in accordance with RoCond Procedures and Guidelines. Road Condition Survey Lane Designation: GENERAL RULE: Negative Direction Asphalt Surface Positive Direction If there are road Negative widening in both Direction outer lane. The designation of Positive Lane number will Direction change. Elements of RoCond Assessment I. RATING SEGMENT I. GAUGING LENGTH I. ROAD DISTRESSES/DEFECTS I. RATING SEGMENTS RATING SEGMENT Segmenting Procedure GENERAL RULE: Assessment of segments designated as between consecutive kilometer posts of homogenous surface types but should not exceed 1300-meters. Segment 1 Concrete Surface L ≤ 1300m RATING SEGMENT Segmenting Procedure: a.) If the distance between two (2) consecutive kilometer posts exceeds 1300m of homogenous surface type, adopt the 1000 meter rating segment and the remaining length should be considered as another segment. RATING SEGMENT Segmenting Procedure: b.) Change in Surface Type RATING SEGMENT Segmenting Procedure: c.) Change in No. of Lanes RATING SEGMENT Segmenting Procedure: d.) Distinct change in the condition of pavement RATING SEGMENT Segmenting Procedure: e.) Segments of asphalt and concrete with length less than 50m are considered not assessable except for gravel/earth which are assessed (regardless of length). Segment 1 Segment 2 Segment 3 Segment 4 (not assessable) (assessable) Asphalt Concrete Earth Concrete Surface Surface Surface Surface L1 L2 200mm Width = 220mm Length = 13m Width = 210mm Length = 1m FLEXIBLE PAVEMENT (ASPHALT) EDGE BREAK Edge Break: 75 < 200mm Width = 150mm Length = 1m FLEXIBLE PAVEMENT (ASPHALT) EDGE BREAK DES FORM: 15 L FLEXIBLE PAVEMENT (ASPHALT) PATCHES Defined as a successfully executed permanent repair with a surface condition similar to the surrounding pavement Assessed over the total area of segment Defective patches are not rated as patches but the defects within the patch are rated under the applicable defects (ex. Cracks, potholes/base failure) The length of patches is recorded per width category FLEXIBLE PAVEMENT (ASPHALT) PATCHES FLEXIBLE PAVEMENT (ASPHALT) PATCHES DES FORM: 10 FLEXIBLE PAVEMENT (ASPHALT) POTHOLES/BASE FAILURE Defined as the holes of various shapes and sizes in the pavement surface reaching the base coarse/unbound layer. For rating purposes, severe cracking with base failure/settlement/ depression shall also be considered as potholes. Potholes/Base failures are recorded as the number of potholes equivalent to 0.25 m2 per pothole. The total area of potholes for the first 100m multiply by 4 to get the no. of potholes. Assessed over the total area of segment. FLEXIBLE PAVEMENT (ASPHALT) POTHOLES/BASE FAILURE No. of Potholes = Area*4 Width 1.0m FLEXIBLE PAVEMENT (ASPHALT) POTHOLES/BASE FAILURE No. of Potholes = Area*4 Width 1.5m FLEXIBLE PAVEMENT (ASPHALT) POTHOLES/BASE FAILURE Split or Cut the rating segment to separate the portion with base failure (at least 50m length) FLEXIBLE PAVEMENT (ASPHALT) POTHOLES/BASE FAILURE DES FORM: FLEXIBLE PAVEMENT (ASPHALT) SURFACE FAILURE Defined as loss of the wearing course layer. These failures can be caused by surface delamination or mechanical damage. Assessed over the total area of segment Surface Failures are recorded as the number of surface failures equivalent to 0.25 m2 per surface failures. The total area of surface failures multiply by 4 to get the no. of surface failures. FLEXIBLE PAVEMENT (ASPHALT) SURFACE FAILURE No. of Surface Failure = Area*4 Width Width 1m 0.5m Length 1m FLEXIBLE PAVEMENT (ASPHALT) SURFACE FAILURE DES FORM: FLEXIBLE PAVEMENT (ASPHALT) WEARING SURFACE This rating includes both Raveling and Bleeding Raveling is the loss or disintegration of stones, typically occurring in the wheel path Bleeding/Flushing is the occurrence of excessive bitumen on the surface of the pavement Assessed over the total area of segment FLEXIBLE PAVEMENT (ASPHALT) Minor Wearing WEARING SURFACE Raveling Bleeding/Flushing FLEXIBLE PAVEMENT (ASPHALT) WEARING SURFACE SEVERITY: Minor 'M' = Surface still relatively smooth with only some loss of fine aggregate or in the case of bleeding there are some signs of excess binder. Severe 'S' = Surface rough or pitted with both fine and coarse aggregate lost or in the case of bleeding the surface is covered with excess binder with skid resistance poor. FLEXIBLE PAVEMENT (ASPHALT) WEARING SURFACE DES FORM: FLEXIBLE PAVEMENT (ASPHALT) PAVEMENT CRACKING Assessed over the total area of segment Rated according to the type of cracking, i.e. Longitudinal, Crocodile, or Transverse Crackings Severity: Wide Cracks (>3mm) Narrow Cracks (3mm) or Narrow Cracks (99mm 2 - Depth of gravel 50mm - 99mm 3 - Depth of gravel 25mm - 49mm 4 - Depth of gravel 0mm - 24mm UNPAVED ROAD B. Material Quality ⮚ The Material Quality of the imported material or exposed sub-grade is rated for Gravel roads. ⮚ The in-situ Material Quality is rated for Earth Roads. ⮚ Local knowledge of the roads must be used, if the surveyors know the road is problematic after rains, then this must be considered when rating the condition. CONDITION SCORE: 1 – GOOD MATERIAL QUALITY 2 – FAIR MATERIAL QUALITY 3 – POOR MATERIAL QUALITY 4 – BAD MATERIAL QUALITY UNPAVED ROAD B. Material Quality Even size distribution with sufficient plasticity to bind the material – no significant oversize material (not bigger than 2 inches in diameter). Material Quality - Good (1) UNPAVED ROAD B. Material Quality Material Quality - Fair (2) Loose material or stones clearly visible UNPAVED ROAD B. Material Quality Poor particle size distribution Material Quality - Poor (3) with excessive oversize material. Plasticity is high enough to cause slipperiness or low enough to cause excessive loose material resulting in loss of traction UNPAVED ROAD B. Material Quality Poorly distributed range of particle sizes, zero or excessive plasticity, excessive oversize material Material Quality - Bad (4) UNPAVED ROAD C. Crown Shape ⮚ Crown Shape is determined to be the height of the center of the road above the edge of the road ⮚ This determines the ability of the road to shed water from it surface CONDITION SCORE: 1 – GOOD MATERIAL QUALITY 2 – FAIR MATERIAL QUALITY 3 – POOR MATERIAL QUALITY 4 – BAD MATERIAL QUALITY UNPAVED ROAD C. Crown Shape Crown Shape - Good (1) >2% crossfall – no significant ponding UNPAVED ROAD C. Crown Shape Crown Shape - Fair (2) Crossfall mostly