“Knowledge is such a treasure which cannot be stolen”. IS (): Plain and Reinforced Concrete - Code of. Practice [CED 2: Cement and Concrete]. India Standard Code Pdf Download. IS Plain and Reinforced Concrete - Code of Practice is an Indian Standard code of. Download IS – IS Code Book (Indian Standards) – We have compiled a Best & Standard Reference Books on Civil Engineering (Indian Standards) IS.
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IS Indian Standard. PLAIN AND REINFORCED CONCRETE -. CODE OF PRACTICE. (Fourth Revision). ICS 0 BIS BUREAU. IS code is very imporatnt books/Notes for a civil engineer, here you can know about IS code or thier name, use etc, also you can download IS CODE PDF. ( Fourth Revision) IS GENERAL CONSTRUCTION IN. Download IS PDF for Civil Engineering. IS PLAIN AND REINFORCED CONCRETE CODE OF PRACTICE (Fourth Revision).
To avoid confusion and error in batching, consideration To allow for the variation in mass of aggregate due to should be given to using the smallest practical number variation in their moisture content, suitable adjustments of different concrete mixes on any site or in any one in the masses of aggregates shall also be made.
In the plant. In batching concrete, the quantity of both cement absence of -exact data, only in the case of nominal and aggregate shall be determined by mass; admixture, mixes, the amount of surface water may be estimated if solid, by mass; liquid admixture may however be from the values given in Table Water concrete plant shall be preferred.
For large and medium F. The material should additional tests to show that the quality and strength be stock-piled for several hours preferably a day before of concrete are satisfactory. The grading of coarse and fine aggregate should be checked as frequently as possible, the frequency The charge to ensure that the specified grading is mixer should comply with IS 1 and IS 12 The maintained.
If there is For other types of more efficient mixers, of formwork. The strength referred to shall be that of manufacturers recommendations shall be followed; concrete using the same cement and aggregates and for hydrophobic cement it may be decided by the admixture, if any, with the same proportions and cured engineer-in-charge.
Oand 2. For further details immediately after removal regarding design, detailing, etc. These tolerances apply to concrete dimensions only, and Release agents should be The forms without coating the reinforcement.
Care shall Reinforcement placing should Within the concrete mass, different types of metal in contact Rough handling, shock loading prior to embedment should be avoided to ensure that bimetal corrosion does and the dropping of reinforcement from a height should not take place. Reinforcement should be secured against displacement outside the specified limits.
After mixing, concrete shall be transported to the formwork as rapidly as possible by methods which will a for effective depth 2oO. Spacers in its final position to avoid rehandling. The concrete between the links or the bars where no links exist shall be placed and compacted before initial setting of and the formwork should be of the same nominal size concrete commences and should not be subsequently as the nominal cover.
Methods of placing should be such as Spacers, chairs and other supports detailed on to preclude segregaion. Care should be taken to drawings, together with such other supports as avoid displacement of reinforcement or movement may be necessary, should be used to maintain the of formwork. As a general guidance, the maxi- specified nominal cover to the steel reinforcement.
Over vibration and under vibration of connections, tests shall be made to prove that the joints concrete are harmful and should be avoided.
Vibration are of the full strength of bars connected. Welding of of very wet mixes should also be avoided. The it is desirable to avoid them. If this is not possible, period of curing shall not be less than 10 days for their number shall be minimized. Concreting shall be concrete exposed to dry and hot weather conditions. Construction joints should above minimumperiods may be extended to 14 days.
Such compounds shall be applied to all exposed uneven surface. It is recommended to clean out laitance surfaces of the concrete as soon as possible after the and cement slurry by using wire brush on the surface concrete has set.
The surface may also be used to provide effective barrier prepared surface should be in a clean saturated surface against evaporation. It is exceedingly difficult and costly to alter concrete Fresh concrete should be thoroughly vibrated near once placed. Hence, constant and strict supervision of construction joints so that mortar from the new concrete all the items of the construction is necessary during flows between large aggregates and develop proper the progress of the work, including the proportioning bond with old concrete.
Supervision is also of extreme importance to check the reinforcement and Where high shear resistance is required at the its placing before being covered. Sprayed curing membranes and release agents should The prevention of moisture loss from the concrete is particularly important if the-water- Part 1 or IS Part 2.
The curing regime should also prevent the development of high temperature gradients within the concrete. The water-cement ratio shall not Exposed surfaces of concrete shall be kept exceed 0. If the charge in the tremie is lost while the space into which concrete is to be deposited. Otherwise it may be leached and of the tremie method, the vertical end piece of become segregated.
Concrete shall be deposited, the pipe line is always inserted sufficiently deep continuously until it is brought to the required height. The bottom doors water shall be one of the following: The bucket shall be filled completely and pipes the lower end of which is always inserted lowered slowly to avoid backwash. The on the surface upon which the concrete is to be concrete emerging from the pipe pushes the deposited and when discharged, shall be material that has already been placed to the side withdrawn slowly until well above the concrete.
They shall be placed carefully in header batch of the mix or the entire contents the and stretcher courses so that the whole mass is. The tremie pipe shall interlocked. Bags used for this purpose shall be be not less than mm in diameter and shall free from deleterious materials.
A separate and also to the faces of the concrete shall not lifting device shall be provided for each tremie exceed one metre.
Stone aggregate of not less pipe with its hopper at the upper end. Unless than 50 mm nor more than mm size shall be the lower end of the pipe is equipped with an deposited outside the steel cages over the full approved automatic check valve, the upper end area and height to be concreted with due care to of the pipe shall be plugged with a wadding of prevent displacement of the cages.
As the grouting proceeds, the concrete. It will be necessary to raise slowly the pipe shall be raised gradually up to a height of tremie in order to cause a uniform flow of the not more than 6 mm above its starting level concrete, but the tremie shall not be emptied so after which it may be withdrawn and placed into that water enters the pipe.
At all times after the the next cage for further grouting by the same placing of concrete is started and until all the procedure. Additional samples may be The amount of grout to be sent down shall be required for various purposes such as to determine the sufficient to fill all the voids which may be either strength of concrete at 7 days or at the time of striking ascertained or assumed as 55 percent of the the formwork, or to determine the duration of curing, volume to be concreted.
Additional samples may also be required for testing samples cured by The care shall be exercised not to disturb the concrete as specimen shall be tested as described in IS The individual If more, the test results of the sample are invalid. For this purpose the values should be arrived at based a The mean strength determined from any group on actual testing.
In all cases, the 28 days compressive of four consecutive test results compiles with strength specified in Table 2 shall alone be the criterion the appropriate limits in co1 2 of Table However, the hardened concrete Where applicable, use should The methods as considered in the design. If within 24 h of removal of the imposed probe penetration, pullout and maturity. If the recovery is less can supplement the data obtained from a limited than 80 percent, the structure shall be deemed to be number of cores.
These methods are based on measuring a concrete property that bears some unacceptable. The accuracy of these methods, With an other materials and of the workmanship, as verified appropriate degree of safety, they should sustain all by inspections, is adequate for safety, serviceability the loads and deformations of normal construction and and durability.
Account should compliance with clearly defined standards for be taken of accepted theories, experiment and materials, production, workmanship and also experience and the need to design for durability.
Calculations alone do not produce safe, serviceable and durable structures. In structural design, account shall be taken of the dead, Unless more accurate calculations are If within 24 h of the removal Part 3 and IS Part 4 respectively. The recovery after the second test should be at least 75 percent of the maximum deflection In this case only 0.
To ensure stability at all times, account shall be taken 4 Foundation movement see IS , of probable variations in dead load during construction, b Elastic axial shortening, repair or other temporary measures. Wind and seismic loading shall be treated as imposed loading. Under transient wind load the lateral sway at the top For seismic. Part 5. The fire resistance of a care shall be exercised by the designer to ensure structural element is expressed in terms of time in hours adequate safety for possible stress reversal.
Fire resistance of concrete elements depends upondetails of member size, cover The stability of a structure as a whole against In cases where dead load provides the restoring moment, Restoring moment ilue to imposed loads ceilings and sacrificial steel in tensile zone, should be shall be ignored. For unsymmetrical or very tall centre to centre distance shall be used. The assumptions made shall be consistent for all the Where a member is built into a masonry wall which For such a The simplifying assumptions as given in Table 13 Shear for Coeffkients Clauses For non- centroid of the area of tension reinforcement and the monolithic construction the design of the membershall maximum compression fibre, excluding the thickness be done keeping in view This will not apply to deep beams.
The shears computed at the face of the support shall be used in the design of the member at that section However, where simplified analysis using coefficients is adopted, In the absence of more accurate determination, the redistribution of moments shall not be done.
The deflection shall half the sum of the clear distances to the adjacent beams generally be limited to the following: For high stmngthdeformedbarsof gradeFe For a cantilever, the clear distance from the free end of the cantilever to the lateral restraint shall not Slabs spanning in one direction and continuous over d supports shall be designed according to the provisions aDDkabk to continuous beams. If such supports are formed slab for one load does not overlap the effective due to beams which justify fixity at the support of slabs, width of slab for another load, both calculated then the effects on the supporting beam, such as, the as in a above, then the slab for each load can bending of the web in the transverse direction of the be designed separately.
If the effective width beam and the torsion in thelongitudinal direction of the of slab for one load overlaps the effective width beam, wherever applicable, shall also be considered in of slab for an adjacent-load, the overlapping the design of the beam. Oand above 2. Where this moment per metre width of slab shall be ratio is one, that is, where the transverse and calculated separately for each load according to longitudinal flexural rigidities are approximately its appropriate effective width of slab calculated equal, the value of effective width as found for solid as in a above and added together for design slabs may be used.
But as the ratio decreases, calculations. The procedure should be as be as given in The slabs spanning in two directions at right angles 2 Determine the points of contraflexure of the and carrying uniformly distributed load may be new support moments [from c ] with the designed by any acceptable theory or by using span moment [from l ].
For determining Extend half the support tension steel at each 3 -bending moments in slabs spanning in two directions end to at least an effective depth or 12 bar at right angles and carrying concentrated load, any diameters beyond the nearest point of accepted method approved by the engineer-in-charge contraflexure. Table 26 for adjacent panels may differ significantly. Where bi-axial bending is considered, it is sufficient to ensure that eccentricity exceeds the The unsupported length, 1, of a compression member minimum about one axis at a time.
Reinforcing steel of same type and grade shall be used b in beam and slab construction, it shall be the as main reinforcement in a structural member. Bundled bars shall be enclosed within stirrups struts in each vertical plane, provided that to be or ties. Bundled bars shall be tied together to ensure an adequate support, two such struts shall the bars remaining together.
Bars larger than 32 mm meet the columns at approximately the same diameter shall not be bundled, except in columns. Such struts shall be of should be taken into consideration, where applicable adequate dimensions and shall have sufficient see afso IS The development length Ld is given by For bars in compression, the values of bond stress for b Stirrups-Notwithstanding any of the bars in tension shall be increased-by 25 percent. Hooks should normally The bearing stressinside a bend in tiy otherbend shall be calculated 1 Bends-The anchorage value of bend shall as given below: The projected For limit state method of design, this stress shall not length of hooks, bends and straight lengths beyond bends if provided for a bar in compression, shall only exceed - 1.
For working Bent 4 tension bar at a re-entrant angle should be avoided. The excess stirrup area shall be not At least one-third of the total reinforcement provided less than 0. Bars in a bundle shall terminate at different points cl For 36 mm and smaller bars, the continuing bars spaced apart by not less than 40 times the bar diameter provide double the area required for flexure at except for bundles stopping at a support.
Adequate end anchorage shall be provided for tension Where splices are provided in the-reinforcing bars, they , b When a flexural member is part of the primary shall as far as possible be away from the sections of lateral load resisting system, the positive reinforcement required to be extended into the maximum stress and be staggered. It is recommended support as described in a shall be anchored to that splices in flexural members should not be at sections where the bending moment is more than 50 develop its design stress in tension at the face percent of the moment of resistance; and not more than of the support.
The compression. Where lap occurs for a tension bar located at: Where spacing limitations and the lapped bar or where the clear distance minimum concrete cover see Where both condition 1 and 2 apply, the lap The following shall apply for spacing of bars: NOTE-Splices in tension members shall be enclosed in spirals made of bus not less than 6 mm diameter with pitch a The horizontal distance between two parallel not more than mm.
NOTE4ldsdwrnutprccludethcuscoflaqex heof f When splicing of welded wire fabric is to be aggregatesbeyond the congested teinforcemt in tb carried out, lap splices of wires shall be made same mcmk, the size of -gates m8y be rsduced so that overlap measured between the extreme aroundcongested reinforcementto comply with thir provi8ioll.
W Greater horizontal. It is the immersed. It shall be not less than the diameter of the bar. Unless the calculation of crack widths shows that a In the case of columns of minimum dimension of mm or under, whose reinforcing bars a Beams - The horizontal distance between do not exceed 12 mm, a nominal cover of 25 mm may parallel reinforcement bars, or groups, near the be used. Structural Members 2 The horizontal distance between parallel The total area ofsuch reinforcement shall be not where less than 0.
Compression reinforcement The maximum spacing of shear reinforcement in beams shall be enclosed by stirrups for effective measured along the axis of the member shall not exceed lateral restraint.
The arrangement of stirrups shall be 0. In no case shall the spacing The rules given in However, this value can be reduced to where 0.
Wherebarsfrom B-6 torsion reinforcement shall be provided as below: Where 8 Spacing of longitudinal bars measured along flanges are in tension, a part of the main tension the periphery of the column shall not exceed reinforcement shall be distributed over the effective mm. If the effective flange width reinforcement is not taken in account in strength exceeds one-tenth of the span, nominal longitudinal calculations, nominal longitudinal reinforcement reinforcement shall be provided in the outer portions not less than 0.
The effective lateral ii Sixteen times the smallest diameter of support is given by transverse reinforcement the longitudinalreinforcement bar to be either in the form of circular rings capable of tied; and taking up circumferential tension or by iii mm.
The ends of the transverse 2 Diameter-The diameter of the polygonal reinforcement shall be properly anchored links or lateral ties shall be not less than one- [see Where an increased 2 If the longitudinal bars spaced at a distance of not exceeding 48 times the diameter of load on the column on the strength of the the tie are effectively tied in two directions, helical reinforcement is allowed for, the pitch additional longitudinal bars in between these of helical turns shall be not more than 7.
In other cases, the a compression member are placed in more requirements of Adequate times the diameter of the largest bar in horizontal support at the offset bends shall be treated the inner row see Fig. Metal pression member are grouped not in ties or spirals so designed shall be placed near not contact and each group adequately tied with more than eight-bar diameters from the point of bend.
Where column faces are offset 75 mm or more, determining the pitch and diameter of the splices of vertical bars adjacent to the offset face shall transverse reinforcement in accordance with be made by separate dowels overlapped as specified The diameter of such transverse in Normally structures occur. Expansion joints shall be so provided that the exceeding 45 m in length are designed with one nor necessary movement occurs with a minimum more expansion joints.
However in view of the large resistance at the joint. The structures adjacent to the number of factors involved in deciding the location, joint should preferably be supported on separate spacing and nature of expansion joints, the provision columns or walls but not necessarily on separate of expansion joint in reinforced cement concrete foundations. Reinforcement shall not extend across structures should be left to the discretion of the an expansion joint and the break between the sections designer.
IS gives the design considerations, shall be complete. All dimensions in millimetres. The depth of the corbel at the face of the support is 1 2. The concrete and reinforcement may be assumed to The lever arm z for a deep beam shall be detemined as 4 The magnitude of the resistance provided to below: Alternatively, the slabs D is as defined in The span to effective depth ratios given evenly distributed.
For voided slabs and slabs constructed of box or I-section units, an effective rib widthshall be calculated They Side face reinforcement shall comply with require- shall be spaced at centres not greater than 1.
Generally ribs shall be formed along each edge parallel to the spanof one When required to contribute to the The recommendations given in The curtailment, For this purpose, the longer span reinforcement shall be provided over the support shall be considered.
The minimum thickness of slab to control cracking. This reinforcement shall shall be mm. For exterior to the reinforcement shall not be less than panels, the width of drops at right angles to the non- 10 mm. In all other cases, cover shall be continuous edge and measured from the centre-line of provided according to Methods of Analysis and Design beams, by columns with or without flared column It shall be permissible to design the slab system by heads see Fig.
The end spans may be shorter but which moment acts. Bending moments at critical cross-section shall -be distributed to the column strips and middle strips as M,,shall be distributed in the following proportions: Interior negative design moment: In the case of recessed or coffered slab which is made solid in the b if the sum of the flexural stiffnesses of the region of the columns, the stiffening effect may columns, XC, does not satisfy a , the positive be ignored provided the solid part of the slab design moments for the panel shall be multiplied does not extend more than 0.
Each frame consists of a row of equivalent columns or supports, bounded Positive momentfor each span b maximum negative moment in the slab at a For each span, the column strip shall be designed to support may be assumed to occur when three- resist 60 percent of the total positive moment in the quarters of the full design live load is on the panel. Moments determined by means of the equivalent frame Negative moment at an interior the periphery of the critical section which is enclosed support by radial projections of the openings to the centroid of the reaction area shall be considered ineffective At an interior support, the column strip shall be see Fig.
Negative moment at an exterior Shear stresses shall be taken as varying the calculated shear stress at the critical section shall linearly about the centroid of the critical section. If the Shear stresses shall be investigated at minimum lengths specified in Fig. Larger successive sections more distant from the support and lengths of reinforcement shall be provided when shear reinforcement shall be provided up to a section required by analysis.
While b Where adjacent spans are unequal, the extension designing the shear reinforcement, the shear stress of negative reinforcement beyond each face of the common column shall be based on the longer carried by the concrete shall be assumed to be 0.
NOTE - D is the diameterof the column and the dimension of the rectangularcolumn in the directionunder consideration. The minimum thickness of walls shall be mm. However, for openings conforming to the following, no special 2 2. The equivalent of rein- a braced wall at any level between horizontal lateral forcement interrupted shall be added on all sides supports, shall be calculated on the assumption that of the openings. Jt shall Reinforced concrete walls subjected to direct L, of lateral restraint.
Design of Shear Reinforcement wall, it may be designed for vertical forces in accordance with In plane bending may be equal to Vu - Tcw. In case of working stress neglected in case a horizontal cross-section of the wall method Vu is replaced by V. The strength of shear is always under compression due to combined effect reinforcement shall be calculated as per The nominal shear stress znu in walls shall be obtained In the case ofstairs with open wells, where spans partly 3 0.
Where flights farther apart than three times the wall thickness or landings are embedded into walls for a length of nor mm. The effective span of stairs without stringer beams shall At the face of the column, pedestal or wall, for.
For reinforcement in the short The remainder of the cone or pyramid araund the concentrated load; reinforcement shall be-uniformly distributed in in this case, the footing shall be designed for the outer portions of the footing. If reinforcement is vertical to two horizontal; and curtailed, the anchorage requirements shall be checked in accordance with The concrete in the supporting or supported member would dowel shall extend into the column, a distance equal be exceeded, reinforcement shall be provided for to the development length of the column bar and into developing the excess force, either by extending the the footing, a distance equal to the development length longitudinal bars into the supporting member, or by of the dowel.
This provision does not supersede the requirement supported column or pedestal and a minimum of four of minimum tensile reinforcement based on the depth bars shall be provided. Where dowels are used, their of the section. Where specific attention is required to limit the designed crack width to a particular value, The acceptable gross errors in design, which might result in limit for the safety and serviceability requirements concentration and excessive width of flexural crack.
In members where cracking design to ensure an adequate degree of safety and in the tensile zone is harmful either because they are serviceability. In general, the structure shall be exposed to the effects of the weather or continuously designed on the basis of the most critical limit state exposed to moisture or in contact soil or ground water, and shall be checked for other limit states. The characteristic values should be based on statistical data if available; where such data The the structure could be assessed from rupture of one or characteristic strength for concrete shall be in more critical sections and from buckling due to elastic accordance with Table 2.
Until the relevant Indian or plastic instability including the effects of sway Standard Specifications for reinforcing steel are where appropriate or overturning. Since data are not Redistribution of the calculated moments nature of loading and the limit state being may be made as given in Redistribution of Moments in Continuous Beams and Frames The values of yf given in Table 18 shall normally be c The elastic moment at any section in a member used.
While assessing the long term effects due to creep the dead load and that pat of the live load likely to be permanentmay only be consided. I This value is to be consideredwhen stability against overturningor stress reversalis critical. An acceptable stress- strain curve is given in Fig. Yield line theory or any other acceptable method e The stresses in the reinforcement are derived may be used.
Alternatively the provisions given in from representative stress-strain curve for the Annex D may be followed. Qpical curves are given in Fig. Attempts should be made to obtain the 30 samples, as early as possible, when a mix is used for the first time.
The calculation of the standard deviation shall be brought up to date after every change of mix design. As soon as the results of samples are available, actual calculated standard deviation shall be used and the mix designed properly. The construction should result in satisfactory strength, serviceability and long term durability so as to lower the overall life-cycle cost.
Quality assurance in construction activity relates to proper design, use of adequate materials and components to be supplied by the producers, proper workmanship in the execution of works by the contractor and ultimately proper care during the use of structure including timely maintenance and repair by the owner.
Some common cases should be specified in a general Quality Assurance Plan which shall identify the key elements necessary to provide fitness of the structure and the means by which they are to be provided and measured with the overall purpose to provide confidence that the realized project will work satisfactorily in service fulfilling intended needs.
The job of quality control and quality assurance would involve quality audit of both the inputs as well as the outputs. Inputs are in the form of materials for concrete; workmanship in all stages of batching, mixing, transportation, placing, compaction and curing; and the related plant, machinery and equipments; resulting in the output in the form of concrete in place.
To ensure proper performance, it is necessary that each step in concreting which will be covered by the next step is inspected as the work proceeds see also Table 8 Assumed Standard Deviation Clause 9.
The proportions of materials for nominal mix concrete shall be in accordance with Table 9. Gradedcoarse aggregateshall be used. Exumple For an average grading of tine aggregate that is. Suppliers and subcontractors activities shall be covered in the plan. A Quality Assurance Plan shall define the tasks and responsibilities of all persons involved, adequate control and checking procedures, and the organization and maintaining adequate documentation of the building process and its results.