“Knowledge is such a treasure which cannot be stolen”. IS (): Plain and Reinforced Concrete - Code of. Practice [CED 2: Cement and Concrete]. Download IS – IS Code Book (Indian Standards) – We have compiled a Best & Standard Reference Books on Civil Engineering (Indian Standards) IS. India Standard Code Pdf Download. IS Plain and Reinforced Concrete - Code of Practice is an Indian Standard code of.
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Download IS PDF for Civil Engineering. IS PLAIN AND REINFORCED CONCRETE CODE OF PRACTICE (Fourth Revision). IS Indian Standard code book for RCC design guidelines - Download as PDF File .pdf), Text File .txt) or read online. A code book for RCC design. IS Indian Standard. PLAIN AND REINFORCED CONCRETE -. CODE OF PRACTICE. (Fourth Revision). ICS 0 BIS BUREAU.
The prepared surface should be in a clean saturated surface dry condition when fresh concrete is placed, against it. In the case of construction joints at locations where the previous pour has been cast against shuttering the recommended method of obtaining a rough surface for the previously poured concrete is to expose the aggregate with a high pressure water jet or any other appropriate means. Fresh concrete should be thoroughly vibrated near construction joints so that mortar from the new concrete flows between large aggregates and develop proper bond with old concrete.
Where high shear resistance is required at the construction joints, shear keys may be-provided. Sprayed curing membranes and release agents should be thoroughly removed from joint surfaces. The period of curing shall not be less than 10 days for concrete exposed to dry and hot weather conditions.
In the case of concrete where mineral admixtures or blended cements are used, it is recommended that above minimumperiods may be extended to 14 days. Such compounds shall be applied to all exposed surfaces of the concrete as soon as possible after the concrete has set. Hence, constant and strict supervision of all the items of the construction is necessary during the progress of the work, including the proportioning and mixing of the concrete. Supervision is also of extreme importance to check the reinforcement and its placing before being covered.
Curing is the process of preventing the loss of moisture from the concrete whilst maintaining a satisfactory temperature regime. The prevention of moisture loss from the concrete is particularly important if the-watercement ratio is low, if the cement has a high rate of strength development, if the concrete contains granulated blast furnace slag or pulverised fuel ash. The curing regime should also prevent the development of high temperature gradients within the concrete.
Supersulphated cement concrete is seriously affected by inadequate curing and the surface has to be kept moist for at least seven days. The water-cement ratio shall not exceed 0.
If the charge in the tremie is lost while depositing, the tremie shall be raised above the concrete surface, and unless sealed by a check valve, it shall be re-plugged at the top end, as at the beginning, before refilling for depositing concrete. Coffer-dams or forms in still water shall be sufficiently tight to prevent loss of mortar through the walls. De-watering by pumping shall not be done while concrete is being placed or until 24 h thereafter.
Otherwise it may be leached and become segregated. Concrete shall be deposited, continuously until it is brought to the required height.
While depositing, the top surface shall be kept as nearly level as possible and the formation of seams avoided. The methods to be used for depositing concrete under water shall be one of the following: c Drop bottom bucket -The top of the bucket shall be covered with a canvas flap. The bottom doors shall open freely downward and outward when tripped.
The bucket shall be filled completely and lowered slowly to avoid backwash. The bottom doors shall not be opened until the bucket rests on the surface upon which the concrete is to be deposited and when discharged, shall be withdrawn slowly until well above the concrete. As far as possible preference shall be given to concentrations represent the maximum permissible natural aggregates. The be as large as possible within the limits specified but sample shall not receive any treatment before testing in no case greater than one-fourth of the minimum other than that envisaged in the regular supply of water thickness of the member, provided that the concrete proposed for use in concrete.
The sample shall be stored can be placed without difficulty so as to surround all in a clean container previously rinsed out with similar reinforcement thoroughly and fill the comers of the water.
For most work, 20 mm aggregate is suitable. The cubes shall given to the use of 10 mm nominal maximum size. The test blocks shall be preparedand tested in in the case of ribs of main beams, the nominal accordance with the requirements off S 1 Part 5. Mixing or curing of concrete with sea water is not 5. All-in-aggregate may be used only where sea water. Under unavoidable circumstances sea water specifically permitted by the engineer-in-charge. Wids claust?
However, water used for scales, loose rust and coats of paints, oil, mud or any curing should not produce any objectionable stain or other substances which may destroy or reduce bond. The presence Sand blasting or other treatment is recommended to of tannic acid or iron compounds is objectionable. Previous experience with and data on such materials Specialist literature may be referred to in such cases.
The characteristic yield strength of Table 2. Table-5 may be used for plain concrete constructions, 5. There is normally a gain of strength beyond 28 days. The design should be based on 28 days charac- IS Ordinary M 10 10 Concrete M 15 6. For a given humidity and M 35 35 temperature, the total shrinkage of concrete is most M40 40 M 45 45 influenced by the total amount of water present in the M JO 50 concrete at the time of mixing and, to a lesser extent, M 55 55 by the cement content.
High M60 60 6. When the designer wishes to use an does not include the elastic strain. The modulus of elasticity is primarily influenced by npe of Aggregate Coeficient of Thermal the elastic properties of the aggregate and to a lesser Expansion for CommtePC extent by the conditions of curing qd age of the Quartzite 1.
The modulus of elasticity is normally related to the Sandstone 0. Granite 0. Suggested such that the concrete is of adequate workability for ranges of workability of concrete measured in the placing conditions of the concrete and can properly accordance with IS are given below: The diameter of tbe needle shall be determined based on the density and spacing of reinforcement bars and thickness of sections. The materials and mix proportions specified and used should be such as f the shape and size of the member.
The of water, oxygen, carbon dioxide, chloride, sulphate and concrete mix to provide adequate durability under these other potentially deleterious substances. Impermeability conditions should be chosen taking account of the is governed by the constituents and workmanship used accuracy of current testing regimes for control and in making the concrete.
Adequate curing is Where freezing and thawing actions under wet essential to avoid the harmful effects of early loss of conditions exist, enhanced durability can be obtained moisture see 13S. Member profiles and their by the use of suitable air entraining admixtures. When intersections with other members shall be designed and concrete lower than grade M 50 is used under these detailed in a way to ensure easy flow of concrete and conditions, the mean total air content by volume of proper compaction during concreting.
Concrete is more vulnerable to deterioration due to chemical or climatic attack when it is in thin sections, Nominal Maximum Size Entrained Air in sections under hydrostatic pressure from one side Aggregate Percentage only, in partially immersed sections and at corners and edges of elements. The life of the strycture can be WW lengthened by providing extra cover to steel, by 20 5fl chamfering the corners or by using circular cross- 40 4fl sections or by using surface coatings which prevent or reduce the ingress of water, carbon dioxide or Since air entrainment reduces the strength, suitable aggressive chemicals.
Chwes 8. Environment Exposure Conditions or polychloroprene sheet; or surface coating based on 1 2 3 asphalt, chlorinated rubber, epoxy; or polyurethane i Mild Concrete surfaces protected against materials should also be used to prevent access by the weatheror aggressiveconditions,except those situatedin coastal area.
For other sizes of aggregate solid aggressive chemicals they should be changed as given in Table 6. For SO, contents near tbe upper limit of any class, cement contents above these minimum are advised.
Alternatively, Portland slag cement conforming to IS having more than 50 percent slag or a blend of ordinary Portland cement and slag may be used provided sufficient information is available on performance of such blended cements in these conditions. To prevent this, the total water-soluble sulphate content of the concrete 8. The sulphate content and materials is necessary, so that deleterious should be calculated as the total from the various constituents do not exceed the limits.
The 4 percent limit does not apply to concrete made 8. Whenever there is chloride in concrete there is an 8. To minimize the chances of cracking and disruption of concrete. Damage to deterioration of concrete from harmful chemical salts, concrete from this reaction will normally only occur the levels of such harmful salts in concrete coming when.
The total amount of source of alkali; chloride content as Cl in the concrete at the time of placing shall be as given in Table 7. Wherever aggregate combination are well established, and do not - possible, the total chloride content of the concrete include any instances of cracking due to alkali- should be determined.
When the materials are unfamiliar, 8. The additions such as fly ash or ground granulated blast furnace slag may be taken into account in the concrete composition with respect to Ihe cement content and water-cement ratio if the suitability is established and as long as the maximum amounts taken into account do not exceed the limit of pozzolona and slag specified in IS Part I and IS respectively.
Clause 8. Sl Nominal Maximum No. Aggregate Size Contents in Table 5 8. Additional protection may be obtained by the use of Tabie 7 Limits of Chloride Content of Concrete chemically resistant stone facing or a layer of plaster Clause 8.
Acid Soluble 8. Full compaction is steam cured nt elevated tempe- particularly important in the vicinity of construction rntureand pre-stressedconcrete ii Reinforced conctite or plain concrete 0. Further advantage can be obtained by use of fly It is essential to use proper and adequate curing ash Grade 1 conforming to IS or techniques to reduce the permeability of the concrete granulated blastfurnace slag conforming to and enhance its durability by extending the hydration IS as part replacement of ordinary of the cement, particularly in its surface zone Portland cement having total alkali content as see Na,O equivalent not more than 0.
Concrete in sea-water or exposed directly along the c Measures to reduce the degree of saturation of sea-coast shall be at least M 20 Grade in the case of the concrete during service such as use of plain concrete and M 30 in case of reinforced concrete. For more guidance specialist of the mix to obtain the densest possible concrete; slag, literatures may be referred.
The mix proportions shall be selected to ensure the 9. The target mean strength of concrete 9. If The standard deviation for each grade of concrete shall design mix concrete cannot be used for any reason on be calculated, separately. Attempts should be made to obtain the 30 samples, as early as possible, when a mix is used 4 Type of mix, that is, design mix concrete or nominal mix concrete; for the first time.
As soon as the results of 9. Quality assurance in M 10 3. M45 The job of quality control and quality assurance Nominal mix concrete may be used for concrete of would involve quality audit of both the inputs as well M 20 or lower.
The proportions of materials for as the outputs. Inputs are in the form of materials for nominal mix concrete shall be in accordance with concrete; workmanship in all stages of batching, Table 9.
Gradedcoarse aggregateshall be used. Exumple For an average grading of tine aggregate that is. Assurance Plan, for its participation in the project. The individual Quality Assurance possible concrete. All ingredients of the concrete Plans shall fit into the general Quality Assurance Plan. A Quality Assurance Plan shall define the tasks and Allowance for building process and its results.
Such documentation bulking shall be made in accordance with IS should generally include: Part 3. NOTE-Quality control charts are recommended wherever the The amount-of the added water shall be adjusted to concrete is in continuous production over considerable period. For the determination of moisture content 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 Where structures are only partially immersed or are in contact with aggressive soils or waters on one side only, IS : unusually severe conditions or abrasionare anticipated, such parts of the work shall be protected by bituminous or silica-fluoride coatings or stone facing bedded with bitumen.
It may be achieved by treating the surface of reinforcement with cement wash or by suitable methods. Design mix concrete is preferred to nominal mix. If design mix concrete cannot be used for any reason on the work for grades of M 20 or lower, nominal mixes may be used with the permission of engineer-in-charge, which, however, is likely to involve a higher cement content. The target mean strength of concrete mix should be equal to the characteristic strength plus 1.
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.