Module 01: Construction Working Drawings PDF
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Ar. Danilo S. Faustino, II, UAP
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This document provides an introduction to architectural and construction drawings. It explores the history of technical drawings, from ancient times to the modern era, and highlights the significance of working drawings in the design and construction process. It includes a discussion of different types of drawings and their applications.
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AR 3A WOOD, CONCRETE, AND STEEL AR 3B CONSTRUCTION AR 3C MODULE 01 The Construction Ar. Danilo S. Faustino, II, UAP Office: College of Architecture and Working...
AR 3A WOOD, CONCRETE, AND STEEL AR 3B CONSTRUCTION AR 3C MODULE 01 The Construction Ar. Danilo S. Faustino, II, UAP Office: College of Architecture and Working Drawings Fine Arts Session: Week 2 No. of Hours: 5 hours Objective: To make the students’ aware of the details and technicalities of the complete set of the working drawings. Introduction What is architectural drawing? Architectural drawing is simply the technical drawing of a house, a building or any kind of structure. Technical drawings are graphic representations such as lines and symbols that follow specific conventions of scale and projection. They are used in architecture, construction, engineering, or mapping. In other word they are a set of sketches, diagrams, and plans, used to design, construct, and document buildings. It's a schematic representation of a building (The Hong Kong Polytechnic University, 2016) Architectural Construction Drawing Sets are also known as working drawing sets. These drawing lay emphasis on what needs to be built and the process that needs to be followed. It is very important to understand the local building standards and codes before working on Architectural Construction Drawings projects. It is very important to hire an experienced and reputed Architectural firm to accomplish this particular phase. Right from the placement of the details to the actual construction or installation of equipment’s, CD Sets are required at every stage. The reason why there is a requirement of a skilled and qualified Architect is because Construction Drawing creation process varies according to the understanding of an Architect. Hence an Architect with mediocre experience of expertise can actually destroy the whole process and the builder ends up spending a lot of money with unnecessary delays in construction. The current trend of developing Architectural working drawings consists of much more details with different views or sheets created for each detail. The standard practices also include the notes and also create standard documents that are attached to the working drawings. Source: Architectural+construction+drawing+research+paper.google.com The CONSTRUCTION WORKING DRAWINGS, or simply construction plans, is a method is of presenting, by means of lines, marks, and symbols, buildings or part of buildings on a two-dimensional surface. They show the physical details needed to build the project. These drawings define the form, location, arrangement and dimension of the work. The working drawings are not picture or sketches, but accurately drawn plans and elevations, usually at a small scale, and frequently with sheets of details at a larger scale. They are graphical presentations on paper that enable the reader to visualize and understand how the building would be constructed and how it functions. They contain details and information to enable one to know the exact picture of all the elements, measurements, and how the various structural parts are to be put together to form the whole structure. The purpose of this is to convey information about the structure in a clear and concise manner. Therefore, it must be drawn with accuracy and legibly. It must be understood by anyone who sees it. There are two types of Working Drawings; the Contract Drawings and the Shop Drawings. CONTRACT DRAWINGS are made by the Architect/Designer which spell out the physical conditions the Contractor must provide when he builds the project. While SHOP DRAWINGS are prepared by the Contractor or subcontractors to guide their own work. HISTORY The first presentation of architectural drawing was through diagrams. The first diagram was made of pointed stick done on soft ground. When man learned to draw a right angle and measure through scale, his diagrams included marks and symbols. Egyptians used limestone and papyrus in drawings. In Assyria and Babylon, plans were drawn on clay tablets, Ancient Greece used whitened or waxed wood while Romans used marble. During the Early Christian era, building of abyss produced master masons who gradually developed a knowledge of architectural drawing. Architectural drawing was born during the Italian Renaissance. It was then that scientific principles of perspective and descriptive geometry were developed. Also, paper and printing were also invented. Michael Angelo and Leonardo da Vinci were architects as well as architectural drafters. Due to technological advancements, Construction Drawings can be produced easily and fast through the use of computers. SET OF WORKING DRAWINGS ARCHITECTURAL DOCUMENTS A1 – Perspective, Location or Vicinity Map, Site Development Plan (Scale 1:200) (see Figure No. 1 for A1) A2 - Floor Plans A3 – 4 Elevations and 2 Sections A4 - Schedule of Doors and Windows A5 - Reflected Ceiling Plans and Details A6 - Blow-up Plans and Details (Kitchen, Stair. Toilet) A7 - Architectural Details STRUCTURAL DOCUMENTS S1 - Foundation plan and details (footings, columns, walls) S2 - Framing Plans and details (Girders, Beams. Slab, Stair) S3 – Roof Framing Plan (Truss and Rafter) PLUMBING/SANITARY DOCUMENTS P1 - Plumbing Layout and Legend P2 - Isometric Septic Tank and Catch Basin Detail ELECTRICAL DOCUMENTS E1 - Electrical Layout and Legend E2 - Electrical Notes and others DRAWING TOOLS Drawings are usually made on sheets of paper like tracing paper. The usual paper size is 20” x 30”. These are fastened on the drawing boards. The drawings are done with the aid of a wide variety of tools. Some basic tools include T-square, triangles, scale, eraser, pencils, and tape. These tools should be properly used in order to produce good drawings. Purchase tools of good quality. ARCHITECTURAL TECHNIQUES There are two parts of architectural drawings: the drawings itself and the notes, which include all pertinent data, such as titles, dimensions, titles, materials and so forth. Notes should be properly lettered, because good drawings deserve good lettering. Architectural draftsmen are artists as well. They should be able to present their drawings with grace. Therefore, they have to develop their craft. Here are some tips : 1. Clean all tools and working surface with clean cloth. Clean your hand, also. 2. All necessary drafting tools must be within easy reach, 3. Backing sheet provides smoother working space, 4. Fasten the paper correctly. 5. Drawing requires certain amount of planning. Therefore, organize considering other information such as dimension, title, etc. 6. Use drafting tools properly. 7. Dust off the erasure crumbs, 8. In using soft pencil, master slight twisting to keep the point sharp and avoid pencil that will smudge the paper. 9. Don’t leave your work exposed on the drawing board. 10. A better end result will be obtained if the mind and hand are not cramped by trying to stop at a given point. Poor good best 11. Observe the meaning of line or the alphabet of line. THE ALPHABET OF LINES The American Society of Mechanical Engineers (ASME) had set standards known as the “Alphabet of Lines.” These standards give meaning to the lines in the drawing. CHARACTER – refers to the type of line like straight line or long and short dashes. DENSITY- darkness of lines. It is necessary so lines will not disappear or fade when copies are made. CONSISTENT- means the quality of work must be equal throughout the drawing. WEIGHT – refers to the thickness of line. These are: Thin lines – hidden, center, section, dimension, leaders, long break, construction lines Wide Lines – visible lines, short break lines Very Wide Lines – border lines and cutting plane lines 1. HIDDEN LINE – formerly called the invisible or dotted line. It is composed of short dashes about 3-4mm long with gaps between dashes about 1-2mm wide. It is used to represent the hidden edges of the object. 2. CENTER LINE – considered the lightest or finest line in a drawing. It represents the axis or center of the object. It consists of long and short dash alternately drawn. The gaps between dashes are about 1-2mm. 3. SECTION LINES – also called cross-hatching drawn at 45-angle. They represent surfaces exposed by cut through. DIMENSION LINE – used to indicate the measurement of an object. It consists three parts; arrowhead, fine line and number or measurement. The fine line has the same thickness or weight as the projection line. The arrowheads are short heavy strokes called flares. 4. PROJECTION LINE or EXTENSION LINE– slightly heavier than the center line. It is composed of long equal dashes about 7mm to 4cm with gaps of about 1-2mm. It is used to project one view to another and to determine the limit of dimension. 5. LEADER LINE – fine broken line with an arrowhead at one end. The broken line consists of a short horizontal line and an inclined line drawn at any convenient angle. It is used for indicating the measurement and name of a part. 6. LONG BREAK (LIMITING LINE) – limiting line is used for breaking the length of an elongated object so that it can be shown without changing the size of its view. Long Break Lines are long, thin, ruled lines that are joined by freehand “zigzags” 7. PHANTOM LINES – used to indicate one or more possible position that may be taken by the object. It is composed of long and very short dash lines. 8. REFERENCE LINE – an irregular fine, curved line with an arrowhead at one end. It is used to label the parts of an object. 9. CONSTRUCTION LINES – guidelines, very thin light lines 10. VISIBLE OUTLINE or OBJECT LINE – represents the visible edges of an object. A heavy stroke of the soft pencil. 11. SHORT BREAK LINES – limiting lines drawn freehand. 12. BORDER LINE – the heaviest or darkest lines in a drawing. 13. CUTTING PLANE LINES – used to show where a section has been taken away. Arrows at the end show the direction of the section. DO’S AND DON’TS OF DIMENSIONING 1. Plan all dimensions. 2. Always put the shortest dimensions closest to the drawings 3. Extension lines may cross each other provided that they are continuous lines. 4. Never use object line as a substitute for a dimension or extension line 5. Dimensions should be legible and don’t interfere with the lines in the drawings. LINE TECHNIQUE Architectural draftsmen develop their own styles of linework just as they develop their own styles of lettering. Linework consists of light and dark lines. 1. CUTTING-PLANE TECHNIQUE – used for section views where lines formed by the cutting plane are darkened. 2. DISTANCE TECHNIQUE – used to show depth in an architectural drawing by emphasizing the lines closest to the observer. 3. SILHUETTE TECHNIQUE – used by darkening the outline of the object. It is known as the oldest line technique. 4. SHADOW TECHHNIQUE – Recessions and extensions can be shown by darkening the edges away from the light source. The light is usually assumed to be coming from the upper left. 5. MAJOR-FEATURE TECHNIQUE – This is commonly used technique. The major elements are outlined, and the elements of lesser importance are drawn with finer lines. ARCHITECTURAL SYMBOLS A system of architectural symbols to indicate certain materials and features has developed through the years. Properly used, these symbols complement the architectural linework and form an attractive and useful language. LETTERING Many beautiful drawings are marred by poor lettering. Lettering is very important in drawing. Commonly used lettering is the Commercial Gothic letters. The American Standard Commercial Gothic Lettering makes use of ¼” for important titles and drawing numbers, 1/8” for lesser headings, and 3/32” for dimensioning and notes. There are six lettering secrets which have been collected by professional draftsmen who use Commercial Gothic lettering. Practice your lettering with these secrets in mind: 1. Guidelines - These are very light lines (usually drawn with a 4H pencil) that aid in forming uniformly sized letters. They are not erased, since they are drawn so lightly that they are not objectionable. 2. Form – The exact form of every Commercial Gothic letter should be memorized and used. Notice that all capital letters except S are based upon straight and circular lines. The numerals and the letter S are based upon the straight and elliptical lines 3. Stability – Letters and numerals should appear stable at all times. 4. Proportion – Nearly all letters are as wide as they are high. Letters narrower than the standard are called “condensed”; and letters wider than the standards are called “extended”. 5. Density – Black lines should use for lettering. This is necessary to improve the appearance of the lettering and to improve its readability so that it will show up well when reproduced. 6. Spacing – proper spacing of letters to form words and words to form sentences is a “must”. PARTS OF ARCHITECTURAL DRAWINGS 1. SITE DEVELOPMENT PLAN – is also known as Plot Plan. The outline and the measurement of the proposed building and its placement on the property are designated. SDP also show other proposed improvements like gates, lawn, service yard, driveways, walks, contours and utilities. Roof plan and landscaping could also be shown The roof plan of the building is not a standard requirement in the working drawing because it can be interpreted from the Roof Framing Plan. However, some designers include it in the Site Development Plan or as a separate detail. The features indicated in the figure are: (1) gutter; (2) hip roll; and (3) ridge roll. 2. FLOOR PLAN – is a sectional drawing obtained by passing an imaginary cutting plane through the walls about 1.20m. above the floor, showing the outline and arrangement of the rooms in the structure. Here are the steps in drawing floor plan/s: a. Layout exterior and interior wall very lightly. Standard Exterior CHB wall measures 0.15m while the interior CHB wall is 0.10m. b. Locate windows and doors on the wall layout, using appropriate symbols. c. Add the floor plan details like stairs. d. Show all built-in equipment like bathroom fixtures, closets, kitchen cabinets and others. Also, indicate furniture layout. e. Dimensioning f. Lettering g. Checking 3. ELEVATION – is a drawing representing the projection of an exterior side of a structure on a vertical plane directly facing it. The view of the proposed building from the street would normally be designated as the FRONT ELEVATION. The right side of the viewer facing the front elevation is the RIGHT-SIDE ELEVATION; while the viewer’s left is the LEFT SIDE ELEVATION; and the opposite of the front view is the REAR ELEVATION. Elevations give information and details on: a. Over-all design and character of the building b. Materials and finishes for the exterior features c. Height of the building and its carious levels d. Approximate or true profile of the building site if not level e. Types and designs of exterior doors and windows 4. SECTION – reveals the interior of the structure as projected on an imaginary vertical plane that passes through a given axis of the building. Section shows: a. The height of the different floor levels as seen from the inside of the structure b. Interior elements of the building c. Contour of the building site if not level d. Profile of the ceiling lines and floor sections. 5. ARCHITECTURAL DETAILS – additional drawings required to supply complete information about the structure. These are enlarged or blow-up drawings which focus only on selected portions of the structure to show in greater detail those parts of the construction. Detail drawings are usually prepared at scale 1:20mts. However other scale may be used. a. Schedule of Doors and Windows b. Blow-up plan of Kitchen and details c. Closet Details d. Details of T&B e. Reflected Ceiling Plan and Details PARTS OF STRUCTURAL DRAWINGS 1. FOUNDATION PLAN The purpose of the FOUNDATION PLAN is to show the structural supports of the proposed structure at the ground level, and/or basement level if the basement is incorporated in the building plan. The principal information it presents are the following: a. position of the columns, masonry walls and other building elements at the foundation level; b. necessary measurements to show the spatial relationships between the building parts, as well as for plotting their exact positions on the ground; c. spaces for concrete slabs on fill and their thickness; sizes and spacing of steel reinforcing and temperature bars, if required; d. foundation work required for other facilities like driveways, outdoor terraces, patios, steps, walkways and other amenities related to the function of the proposed building. To complement the FOUNDATION PLAN, separate detailed drawings of columns, footings and other members supporting the base of the building and transmitting its dead and live loads to the ground are prepared at a bigger scale, usually 1:20 meters. Each structural member is given identification mark like; C1, C2, C3, for any three different kinds of columns; or WF1, WF2, WF3 for three kinds of masonry walls. The DETAIL DRAWINGS of the columns, footings and foundation walls should be prepared on the same drawing sheet to facilitate easy and convenient easy cross-reference between them. 2. FLOOR FRAMING PLAN There is an old saying that should always be remembered: A good design id easy to build.” This implies a thorough coordination of architectural and structural requirements. It means that the plan should permit simple direct framing and spans within economical limits, except where a prime requirement justifies more expensive construction. It is exemplified by the functional use of appropriate building materials and assemblies. LOCATING COLUMNS The first step is to determine the location of all the columns and the other structural elements that are available to help support the floor and roof system. The position of each column should be determined and marked on copies of the architectural floor plans. Each tier of columns should be concentric as far as architectural considerations permit. Obvious exceptions are setbacks where offsets less than the column spacing are required in the exterior building walls, or where large interior areas, such as ballroom, must be clear of obstructions. The location of exterior columns is largely controlled by windows or other exterior openings; and that of interior columns by partition. It is often impossible to obtain an ideal structural arrangement, but there are a few considerations which should be borne in mind. The best column spacing usually results from dividing the supported area into squares or rectangles of approximately equal size. A column spacing of less than 6.0 meters is seldom desirable unless there are unusual conditions. A span of 4.8 mts. have been found economical. A maximum span of 7.5 mts. where conventionally designed reinforced concrete girder framing is used and 8.0 mts. for rolled steel girder is generally desirable from the viewpoint of structural economy. LOCATING THE GIRDERS AND BEAMS: Having located the columns and other structural vertical elements, the designer is ready to complete the structural diagram. In this type, it is necessary to decide between a short span and a long span system for the floor construction. The term short-span identifies a group of structural floors design which are used on spans varying from about 1.8 mts to 3.0 mts and consequently require one or more intermediate beams between each line of columns. Long-span systems are those capable of spanning, under varying loads within the usual range, from 6.0 mts to about 9.0 mts., thus eliminating the need for intermediate beams. TYPICAL DESIGN FOR R.C. FLOOR FRAMING 3. ROOF FRAMING DRAWINGS Roof Framing Drawings show the details for the roofing system. The common materials for the roofing system, nowadays, is steel for the trusses and the roof covering, galvanized iron or G.I. sheets are used. In the roof framing plan, one can see the skeleton of the roofing system showing the roof beams’ location, purlins, trusses/rafter and the gutter. Details of trusses are shown including the blow-up detail of eaves. ELECTRICAL PLANS For this course, electrical power layout and electrical lighting layout and legend are to be shown. Aside from power and lighting layout, in reality, electrical plans should also include, load computations, riser diagrams, and electrical notes. These drawings should be prepared, signed and dry-sealed by a professional electrical engineer or master electrician. SANITARY/PLUMBING Sanitary Drawings are prepared, signed and dry-sealed by a licensed sanitary engineer. Sanitary drawings show the arrangement of toilet fixtures, water layout, sewer layout, isometric of the layout, catch basin details, septic vault details, and legend. For the plate, the students are required to do the water line, sewer line, and legend. THE FOLLOWING SHEETS SHOW SOME SAMPLES OF THE DIFFERENT PARTS WORKING DRAWINGS SITE DEVELOPMENT PLAN AR 3A WOOD, CONCRETE, AND STEEL AR 3B CONSTRUCTION AR 3C MODULE 02 Ar. Danilo S. Faustino, II, UAP Historical Background of Construction Office: College of Architecture and Technology Fine Arts Session: Week 2- Week 3 No. of Hours: 10 hours Objective: to familiarize the students about the fundamental background in construction technology, its origin and development. Introduction Construction history is a thriving domain (Picon, 2006). Construction is the act of building something on site or the manner in which materials are assembled. Building technology, on the other hand, is discovering how to use tools and techniques efficiently to get the best result. The development of the construction industry has taken a quantum leap from its basic and traditional form to the highly technological processes (Friedman, 2013). Historical Background During the Stone-Age Era, men lived in caves. When these early settlers experienced the discomfort of living in caves, they tried to build “lean-to” houses. This was the first constructed structure. As men tried to discover the materials around them to satisfy their basic need for shelter more different structure evolved. The most magnificent architectural example of the Stone-Age Era was the Stonehenge in England. Human muscles were used to move huge stones from quarrying place to its final position. The production process was very slow and labor-intensive requiring a great Source: construction+history.google.com number of workers to complete structure for a long period of time. Stone- construction was construction method of this early period. This method was carried up to the Asian civilization. Structures of this era were massive and monumental. Labor force was so intense that the invention of wedge, lever, sledges, roller and inclined plane were so helpful to somehow ease workers from the enormous task. This was evident in the building of the great pyramids in Egypt. It is believed the Egyptians were the first to practice manpower management, because leaders had to manage a large number of slave labor on pyramid and temple building of huge stonework. Greeks built temples for their gods and goddesses, and civic structures for political and social purposes. Marble, since abundant in the place, was the common material used in their structures. They also used wood trusses for some of their structures. Soon, another method of construction evolved, the CONCRETE Method. Romans should be credited for the development of this method. The use of cement started during the Roman days, due to the discovery of POZZOLANA. Cement was later improved through the development of Portland cement. Concrete method was later improved, and now we have the Reinforced Concrete. When Industrial Revolution rose, STEEL was developed. This paved way to the development of tools and machinery such as cranes, derricks, hoists and shovels earthmoving equipment which provided less labor operations and made field productivity soar. Availability of electricity, internal combustion engine and electrical motors replaced steam to make construction tools and equipment even more mobile and efficient. The development of production methods in construction has taken a slightly different path since the mid of the 1900s. It has undergone four phases of development namely; 1. Traditional, in 1950s, 2. First Industrial phase, 1960s, 3. Subcontracting phase, 1970s, and 4. Second Industrial Phase, 1980s “Traditional construction is characterized by site operations where skilled craft operatives work on relatively unprocessed materials. Non-craft laborers and a relatively small amount of plant support skilled workers. Thereof, a high proportion of the value of a building is added on-site, rather than off-site in a factory. Towards the end of the 1950s, however, greater attempts were made to emulate manufacturing. The construction process was industrialized by carrying out more of the construction process off-site, in factories. A typical example of this period was systems building – wall and floor panels were prefabricated off-site, to be bolted together on site. The intention was that large numbers of housing units could be built quickly, thus solving the housing shortage, which had existed since 1945… This first attempt to industrialize building production was largely unsuccessful – the systems were poorly designed and executed. Consequently, changes to social and organizational factors gathered pace in 1970s. The main change was the shift from direct employment to self-employment and labor only subcontracting. The principal effect of this was to create a stronger link between pay and productivity. This was because those employed were now paid a lump sum for carrying out a set amount of work, rather than a regular weekly wage. Hence, this particular payments-by-results system came to be known as the ‘lump’. With the changes described above, the stage was set for a new phase of industrialized construction. Once again, prefabricated components are being used structurally. The impact of these changes has been far reaching. The main focus of value added has shifted from the site to the factories where materials and components are made. Although the workforce is more flexible and has the potential to be multi-skilled, there has nevertheless been an increase in specialization of a sort. This is due to the division, and possible further subdivision, of work into packages.”(Stephen Lavender. 1996, pp. 268-271). As construction technologies developed, Construction Method will continuously evolve. DEVELOPMENT OF CONSTRUCTION METHOD 1. Stone construction 2. Wood Construction 3. Concrete Construction 4. Steel Construction 5. Prefabricated Construction STRUCTURAL DEVELOPMENT 1. trabeated - post and lintel 2. arcuated arch and pier 3. truss construction 4. corbel or cantilever CONCRETE –is an artificial stone as a result of mixing cement, aggregates and water. Concrete is the only major building material that can be delivered to the job site in a plastic state. This unique quality makes concrete desirable as a building material because it can be molded to virtually any form. The two major components of concrete are cement paste and inert materials. The cement paste consists of Portland cement, water and some air either in the form of naturally entrapped air voids or minute, intentionally entrained air bubbles. The inert materials are usually composed of fine and coarse aggregates. CEMENT – is a binding agent or glue, derived from the Latin word, “calmentum,” the name of a limestone, chips of which were used in mortar more than 2000 years ago in ITALY. COMMONLY USED CEMENT: 1. Portland 2. Pozzolana The Assyrians and Babylonians used clay as the bonding substance or cement. The Egyptians used lime and gypsum cement. In 1756, British Engineer, John Smeaton made the first modern concrete (hydraulic cement) by adding pebbles as coarse aggregate and mixing powered brick into the cement. In 1824, Joseph Aspdin, English bricklayer, a mason and an inventor, invented the Portland cement named after the island of Portland in the English Channel. Aspdin created the first true artificial cement by burning ground limestone and clay together. The burning process changed the chemical properties of the materials and created stronger cement. Its composition is 60% lime and about 25%silica together with smaller proportions of alumina, iron oxide and gypsum. The lime is obtained from limestone, silica and alumina from clay, and iron oxide from iron core. The gypsum was added after burning to regulate the set of hardening time of the cement. POZZOLANA – is a finely ground siliceous material which, as such, does not possess cementitious property in itself, but reacts in the presence of water with lime (calcium hydroxide) at normal temperature to form compounds of low solubility having cementitious properties. The action is termed pozzolanic action. Pozzolanas can be used in combination with or for the partial replacement of Portland cement. AGGREGATES – are inert materials that when bound together into conglomerated mass of Portland cement and water form concrete, mortar or plaster. CATEGORIES OF AGGREGATES: 1. COARSE AGGREGATES – that portion of aggregate that is retained on No. 4 (4.76 mm) sieve. It should easily fit into the forms and in- between rebars, and not larger than 1/5 of the narrowest dimension of the forms or 1/3 of the depth of the slab or ¾ of the minimum distance between rebars. 2. FINE AGGREGATE the product of natural disintegration of silica- bearing or calcium-bearing rock. Fine aggregates or sand are those that passes through No. 4 sieve and retained by a No. 200 (74 micron) sieves. WATER – potable water is satisfactory for use in concrete mix. WATER-CEMENT-RATIO – the proportion of water to cement to control the strength of concrete. HYDRATION – the setting up and the hardening of the cement paste which is caused by a chemical reaction between the cement and water. LAITTANCE – the adverse effect of excess water in a proportion for concrete mix. SALAMANDER – is an oil burning stove used in heating the water or aggregates in cases of freezing weather to keep it above 50 degrees F for purposes of 7 days curing. ADMIXTURE OR ADDITIVES – added to the basic ingredients to change the basic nature of concrete. TYPES OF ADMIXTURE OR ADDITIVES: 1. ACCELERATOR – speeds up the hardening or setting of concrete. 2. RETARDER – slow down the hardening 3. AIR-ENTRAINING AGENT – substances w/c holds air bubbles in concrete, to resist deterioration 4. DISPERSAL AGENT – prevents bleeding of water or moisture to the surface of concrete 5. CONCRETE HARDENER – improves hardness or denseness of concrete 6. WATER-REDUCING AGENT – improves workability of concrete 7. CONCRETE WATRPROOF – makes concrete more watertight 8. BONDING AGENT – improves bonding between old and freshly poured concrete 9. CONCRETE COLORING AGENT – produces colored surface 10. SET-INHIBITING AGENT – inhibits the set of cement paste 11. SURFACE SEALING AGENT–prevents evaporation of water from new concrete 12. GAS FORMING AGENTS-develops the potential strength of cement 13. POZZOLANIC ADMIZTURE-used for pozzolan cement decreases its weight per cubic meter. CONCRETE MAY BE DIVIDED INTO THREE (3) TYPES: 1. MASS OR PLAIN CONCRETE – a conglomeration of concrete materials producing solid mass. 2. REINFORCED CONCRETE – a concrete with reinforcement embedded in such manner that the two materials act together in resisting forces. R.C. was invented by Joseph Monier in 1849 and received patent in 1867. Monier was a Parisian gardener who made garden pots and tubs of r.c. with an iron mesh. He exhibited his invention at the Paris Exposition in 1867. 3. PRESTRESSED CONCRETE a. Pretensioning or bonded prestressing b. Post Tensioning or Unbounded prestressing PROPORTIONING OF CONCRETE MIXTURE The right proportioning of the ingredients of concrete provides a balance between the requirements of: a. economy c. strength e. appearance b. workability d. durability CONCRETE MIXES: CLASS OF MIXTURE CEMENT SAND GRAVEL Bags 40 kg cu. ft. cu.m. cu. ft. cu.m AA 1 1½ 0.043 3 0.085 A 1 2 0.057 4 0.113 B 1 2½ 0.071 5 0.142 C 1 3 0.085 6 0.170 TESTS FOR CONCRETE: 1. SLUMP TEST – check the amount of water placed in the mixture PROCEDURE: a. Place the freshly mixed concrete inside the mold in 3 layers each rodded separately by 16mm rod 25 times. b. Level the mold and lift at once c. Measure the slump action immediately by getting the difference in height between the height of the mold and the top of the slumped concrete RECOMMENDED SLUMPS FOR VARIOUS CONSTRUCTION TYPE OF CONSTRUCTION MAX. (cm) MIN (cm) r.c. foundation wall & footing 13 5 plain footing, caissons & sub-structure wall 10 2.5 slabs, beams, and reinforced walls 15 7.5 columns 15 7.5 pavement 7 5 heavy mass construction 7 2.5 2. COMPRESSIVE STRENGTH TEST – process applied in determining strength of concrete. 3. CONSISTENCY – refers to the state of fluidity of freshly mixed concrete. PROCEDURE: a. for a coarse aggregate not more than 5 cm diameter, prepare a cylindrical specimen 15 cm diameter and 30 cm long. b. For aggregate more than 5 cm diameter, prepare 3 times the maximum size of the aggregate and a height double its diameter. c. The mold should be of metal placed on a plane surface preferably 6-12 m. plate d. Place the fresh concrete inside the mold in 3 separate equal layers rodded separately with 16mm rod 25 strokes e. Level the surface with trowel and cover with a glass or plane steel. f. After 4 hours, cover the specimen with a thin layer of cement paste and cover again with planed metal or glass g. After 24 hours, curing shall be made in a moist atmosphere at 21 deg C. h. Test should be done 7 and 28 days period. i. Ascertain that both ends of the specimen are perfectly leveled j. Specimen is placed under a testing machine; then a compressive load is applied until the specimen fails. The load that makes the specimen fail is recorded. k. The recorded load divided by the cross sectional are of the cylinder gives the ultimate compressive unit stress of the sample. SPECIFIED COMPRESSIVE STRENGTH Class AA = 4500 psi = 35 Mpa A = 4000 psi = 30 Mpa B = 3500 psi = 25 Mpa C = 3000 psi = 20 Mpa D = 2500 psi = 15 Mpa PLACING AND FINISHING CONCRETE Concrete may be mixed on site, at the batching plant or even on the way to the construction site in a transit mix truck which has a large drum on it. Concrete shall be deposited on its final position without segregation, re- handling or flowing. Placing shall be done preferably with buggies, buckets or wheelbarrows. No chutes shall be allowed to except to transfer concrete from hoppers to buckets, buggies or wheelbarrows in which case they shall not exceed 20 ft in aggregate length. No depositing of concrete shall be allowed without the use of vibrators, unless authorized in writing by the designers and only for usual conditions where vibrators is extremely difficult to use. VIBRATOR- is a tube that is closed at one end. It is about 12” in length and 2” or 3” in width. A long hose containing a flexible shaft is fastened to the open end and put down into the wet concrete. The shaft in the hose is turned on by a gasoline engine or an electric motor which causes the tube or vibrator head to shake. The vibration forces the concrete tightly against the form and gets rid of air bubbles. Vibrator is used to settle the concrete around the forms and the reinforcement. After the concrete has been placed, the surface is made level with the top of the form by using a straightedge set on screeds. If the concrete slab is very large additional screeds must be set in between the ones on the form faces. Then, the cement finisher uses wood float back and forth over the surface until no coarse particle shows. Finally, a smooth finish called steel trowel finish is applied by moving the steel trowel back and forth over the surface. METAL REINFORCEMENT Concrete has tremendous compressive strength and durability. However, it has poor strength in tension. By adding STEEL supports embedded into the concrete, its tensile strength is improved considerably. Rebars also make thinner sections of concrete. The bond between concrete and steel bars must be sufficiently strong to prevent any relative movement between the reinforcement and the surrounding concrete. Reinforcing steel must be free of rust, scale, oil, or any surface material that could affect bonding. Rebars may be round or square. Smaller sizes are usually round, while over 1’ in diameter may be round or square. KINDS OF REINFORCING BARS 1. DEFORMED BARS – in order to obtain a strong bond between concrete and steel, rebars are manufactured with surface deformation. Each has been run through a machine at the steel mill that presses ridges into different patterns. 2. REINFORCING MESH – like wire fencing except that it is made of heavier wire. Reinforcing mesh is made in widths of 4’,6’, or 100’, delivered to the construction site in rolls. 3. PLAIN REBARS Deformed Bar Sizes NOM UNIT near ASTM 6M 7.5M 9M 10.5M 12M dia (mm) WT. Designation (19.68’) (24.6’) (29.52’) (34.44’) (39.36’) 6 0.222 No. 2 1.332 1.665 2.000 2.331 2.664 10 0.616 3 3.696 4.620 5.544 6.468 7.392 12 0.888 4 5.328 6.660 7.992 9.32 10.656 16 1.579 5 9.474 11.843 14.211 16.580 18.948 20 2.466 6 14.796 18.495 22.194 25.893 29.592 25 3.854 8 23.124 28.905 34.686 40.467 46.248 28 4.833 9 28.998 36.248 43.497 50.747 57.996 32 6.313 10 37.878 47.348 56.817 66.286 75.756 36 7.991 11 47.946 59.933 71.919 83.906 95.892 MINIMUM CONCRETE COVER 1. footings and the like – 8 cm 3. slabs – 2 cm to 4 cm 2. beams – 4 cm to 5 cm 4. thin shells – 2 cm BUILDING FORMS Concrete is a very versatile material. It can take any shape one wish to have because of its plasticity. Building forms are necessary to shape the concrete. BUILDING FORM is a temporary boarding, or sheathing or pans used to produce the desired shape and size of concrete. Forms should be watertight, strong enough and rigid to sustain weight of concrete, economical and simple. FORMS MUST BE: a. built so that it can be removed easily without changing the concrete or the materials; b. strong enough to keep from bulging from the weight of the wet concrete; c. economical and simple. CONSIDERATION ON SELECTION OF FORM: 1. Cost of materials 2. construction and assembling cost 3. number of times it could be used 4. strength and resistance to pressure, tear and wear. TYPES OF FORMWORK MATERIALS 1. wood/lumber 2. steel 3. combination TWO TYPES OF FRAMING FOR WOOD FORMS: 1. longitudinal rib type 2. perpendicular or cross rib type GREASING OF FORM Wood forms are greased or oiled to prevent it from absorbing the water in the concrete. Absorption of water causes the swelling and warping of forms. The mineral oil or paraffin are the most satisfactory to use but crude oil is the cheapest, but also preferred if mixed with one part of grease to 3 parts of oil. This mixer is required in warmer weather. Greasing should be done after the steel bars have been set to its final position. FORMS CAN BE SECURED WITH: 1. nails 4. bolts 2. cleats and braces 5. clamps 3. tie wires TWO TYPES OF FRAMING FOR WOOD FORMS 1. character of structure 2. availability of equipment and materials 3. anticipated repeat use or forms 4. familiarity with method of construction 5. ultimate shape, dimensions and surface finish SCAFFOLDING AND STAGING SCAFFOLDING – is a term used for small construction of lumber framework that serves as a guide and support for columns, beams, girders, flooring, and wall forms, which at the same time used as flatform of workers in building construction. It is also a temporary framework for other construction purposes. STAGING – is a more substantial framework progressively built up as building rise up. FALSE WORK – is another term for scaffolding and staging. Experience proves that economy of materials for scaffolding and staging result in a big loss due to: 1. delay of work 2. higher labor cost 2. accident 3. sub-standard quality of work Primary Cause of Accidents: 1. The use of poor-quality lumber 2. inadequate support and bases. 3. inadequate nails and other materials for economy sake PARTS OF STAGING: 1. vertical support 2. base support 3. horizontal braces 4. block or wedge support 5. diagonal support and/or braces ALLOWING CONCRETE TO SET Concrete is set when it will retain or hold the shape given by its particular form. Concrete which is set is firm, but is not hard or strong. The amount of time for concrete to set depends upon the kind of concrete used and the temperature and humidity during the time it is in the form. However, concrete will usually set in 12 to 24 hours. It usually takes a much longer period of time for concrete to become hard and strong. CURING CONCRETE Curing the concrete means the process through which the concrete becomes hard and strong. Not a result of concrete drying out, but it results from chemical reaction of the elements within the concrete. Techniques to keep the moisture in the concrete for 14-28 days a. curing with water b. curing with sealing membranes STRIPPING – is the process of removing the forms from around the concrete. GREEN CONCRETE – refers to concrete which has set but not yet cured. SCHEDULE OF STRIPPING OF FORMS PARTS OF STRUCTURE CLASSIFICATION TIME REQ’D 1. footings a. massive a. 1 day b. cantilever b. 5 days c. slab footing c. 3 days 2. walls and pilaster a. massive (12”thk. or >) a. up to 2’ high 1 day retaining wall, basement add 1 day for every 3’ elev. Shafts, bank vaults ht. or fraction thereof b. thin walls ( 16x the Ø of the main rebars; b. not > 48x the Ø of the lateral ties; c. not > than the shortest dimension of the cross section of the column. BUNDLED BARS – is recommended to accommodate the required steel bars and at the same time provide enough space for the concrete, thereby, observing the rules and specifications as to the spacing of bar limitation and the required concrete protective covering. Hooks for Rebars TYPES: FOOTINGS – FULL HOOK TIES – HALF HOOK COLUMNS - BEND HOOK – BETTER HOLD AT THE CONCRETE A. hook is provided to develop anchorage. B. PRINCIPLE OF R.C. TIED COLUMN C. REINFORCING & LATERAL TIE ARRANGEMENT D. ATTACHMENT TO FOOTING E. DETAILS OF TIED COLUMN / PIER E. COLUMN CONSTRUCTION 1. SPIRAL COLUMN – where circular concrete core is enclosed by spirals with vertical or longitudinal bars. The vertical reinforcement is provided with evenly spaced continuous spiral held firmly in position by at least three vertical bar spacers. 2. COMPOSITE COLUMN – structural steel column is embedded into the concrete core of a spiral column. 3. COMBINED COLUMN – a column with structural steel encased in concrete of at least 7 cm thk. reinforced with wire mest surrounding the column at a distance of 3cm inside the outer surface of the concrete covering. 4. LALLY COLUMN – a fabricated post made of steel pipe provided with a plain flat steel bars or plate which hold the girder, girts, or beam. TYPES OF STEEL COLUMNS 1. STRUTS OF ONE OR TWO ANGLES – 2 angles of double strut are riveted together by rivets driven through washers placed between the two angles at intervals of 4 to 6 feet. 2. STARRED ANGLES - 2 or 4 angles are connected with batten plates spaced at intervals of 3 to 4 feet. 3. LATTICED COLUMNS – made of channels/angles connected by lattice bars. 4. ROLLED H-COLUMN – obtainable with depths ranging from 6” to 16”. 5. BUILT-UP COLUMN – H-shaped section formed by a combination of plates and angles. 6. TOP CHORD SECTION – heavy trusses unsymmetrical and are made of 2 rolled 7. COLUMNS FOR BENTS – pair of channels and an I-beam with batten plates at intervals of 3 to 4 feet connecting the flanges of the channels. 8. BATTENED COLUMNS – 2 component parts of a column are connected only by batten plates. 9. BOX COLUMNS 10. LALLY COLUMNS – made up of cylindrical steel pipe shell filled with 1:1/2:3 Portland cement concrete.