BS 1881-122-1983.pdf

BRITISH STANDARD BS 1881-122: 1983 Incorporating amendment No. 1 Testing concrete Part 122: Method for determination of water absorption UDC 666.972.017:691.32:620.1 BS 1881-122:1983 This British Standard, having been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Committee, was published under the authority of the Board of BSI and comes into effect on 31 January 1983. © BSI 12-1998 The following BSI references relate to the work on this standard: Committee reference CAB/4 Draft for comment 80/14205 DC ISBN 0 580 12959 4 Cooperating organizations The Cement, Gypsum, Aggregates and Quarry Products Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: The organizations marked with an asterisk in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Association of Consulting EngineersDepartment of Transport* Association of County CouncilsFederation of Civil Engineering Contractors Association of District CouncilsGypsum Products Development Association Association of Metropolitan AuthoritiesInstitute of Quarrying* Autoclaved Aerated Concrete Products Institution of Civil Engineers* AssociationInstitution of Highway Engineers* British Precast Concrete Federation Ltd.*Institution of Municipal Engineers* British Quarrying and Slag Federation*Institution of Public Health Engineers British Railways BoardInstitution of Structural Engineers* British Ready Mixed Concrete Association*Institution of Water Engineers and Scientists* British Steel IndustryNational Federation of Building Trades Cement Admixtures AssociationEmployers* Cement and Concrete Association*Natural Environment Research Council Cement Makers Federation*(Institute of Geological Science) Chemical Industries AssociationRoyal Institute of British Architects* Concrete Society Limited*Royal Institution of Chartered Surveyors* County Surveyors Society*Sand and Ballast Hauliers and Allied Trades Department of the Environment (Building Alliance Research Establishment)*Sand and Gravel Association Limited* Department of the Environment (PSA)*Society of Chemical Industry* Department of the Environment (Transport Stone Federation and Road Research Laboratory)* British Civil Engineering Test Equipment Greater London Council Manufacturers AssociationInstitute of Concrete Technology Electricity Supply Industry in England and Coopted member Wales Amendments issued since publication Amd. No.DateComments 6180July 1989Indicated by a sideline in the margin BS 1881-122:1983 © BSI 12-1998i Contents Page Cooperating organizationsInside front cover Forewordii 1Scope1 2Definitions1 3Apparatus1 4Test specimens1 5Procedure1 6Calculation and expression of results1 7Test report2 Figure 1 Correction factor3 Publications referred toInside back cover BS 1881-122:1983 ii © BSI 12-1998 Foreword This Part of this standard prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Committee, is a revision of clause 7 of BS 1881-5:1970, which has been deleted by Amendment No. 1 to that standard. The water absorption test in this Part is basically unchanged from that in the 1970 edition. No estimate of repeatability or reproducibility is given in this Part of this British Standard. Reference should be made to BS 5497-1 for further information on the determination of repeatability and reproducibility. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. BS 1881-122:1983 © BSI 12-19981 1 Scope This Part of this British Standard specifies a method for the determination of water absorption of concrete specimens cored from a structure or precast component. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this Part of this standard the definitions given in BS 5328 apply. 3 Apparatus 3.1 A balance, capable of weighing the specimen up to 5 kg to an accuracy of 0.1 %. The balance shall be calibrated on initial commissioning and at least annually thereafter using weights of which the accuracy can be traced to the national standard of mass. The balance shall be checked after relocation or disturbance. A certificate stating the accuracy shall be obtained from the organization carrying out the check. 3.2 A suitable coring machine, with a cylindrical bit having an impregnated or set diamond cutting edge for cutting a 75 ± 3 mm diameter core. NOTEA pillar drill or portable electric drill of about 12 mm nominal size with reduction gearing can generally be adapted for this purpose. 3.3 A well ventilated drying oven, complying with BS 2648, except that the internal space may exceed 0.085 m3, in which the temperature is controlled at 105 ± 5 °C, and such that the specimens can be placed in the oven as described in 5.1. 3.4 A tank, at least 125 mm deep, containing clean water maintained at a temperature of 20 ± 1 °C. 3.5 A dry airtight vessel, e.g. desiccator, of sufficient size to take the set of three specimens to be tested. 4 Test specimens 4.1 Preparation. For a representative sample, obtain a set of three specimens by coring from the full thickness of the concrete when this is between 32 mm and 150 mm, or by obtaining a core 75 mm long when the thickness of the specimen is greater than 150 mm. The diameter of each core shall be 75 ± 3 mm. Cores shall be drilled, as far as possible, perpendicular to the surface and in such a manner as not to damage the core. Mark each core clearly with its identification mark immediately after cutting, and record the orientation of the core. Cores that have been broken out of larger samples shall have the broken ends trimmed approximately square with the axis. NOTEOne end of each specimen should preferably be from one of the faces which would normally be exposed when the unit is in use. 4.2 Measurement of density. Measure the density of the specimens in accordance with BS 1881-114. 4.3 Measurement of dimensions. Measure the dimensions of the specimen in accordance with BS 1881-114. 4.4 Age of specimens at test. The test for absorption shall be made when the age of the concrete is 28 days to 32 days, which means that drying of the specimens shall begin at an age of 24 days to 28 days. NOTEIf the absorption test is carried out on concrete less than 28 days old an appreciably higher value may be obtained. Conversely, the absorption at ages greater than 28 days might be appreciably less. These variations are dependent, amongst other factors, on the rate of hydration of the cement. 5 Procedure 5.1 Place the three specimens in the drying oven (3.3) so that each one is not less than 25 mm from any heating surface or from each other. Dry the three specimens in the oven for 72 ± 2 h. 5.2 Further specimens shall not be placed in the same oven during the drying process and there shall be free access of air to all surfaces of the specimens. On removal from the oven, cool each specimen for 24 ± 0.5 h in the dry airtight vessel (3.5). Weigh each specimen and immediately completely immerse in the tank (3.4) with its longitudinal axis horizontal and at a depth such that there is 25 ± 5 mm of water over the top of the specimen. 5.3 Leave the specimens immersed in the water for 30 ± 0.5 min, unless otherwise specified. Remove each specimen, shake it to remove the bulk of the water and dry it with a cloth as rapidly as possible until all free water is removed from the surface. Weigh each specimen. 6 Calculation and expression of results The measured absorption of each specimen shall be calculated as the increase in mass resulting from immersion expressed as a percentage of the mass of the dry specimen. A correction factor according to the length of the specimen shall be obtained from the curve shown in Figure 1. The product of this correction factor and the measured absorption shall be known as the corrected absorption, this being the equivalent absorption of a core having a length of 75 mm. The results shall be expressed to the nearest 0.1 %. BS 1881-122:1983 2 © BSI 12-1998 The correction factor related to size is based on the formula 7 Test report 7.1 General. The report shall affirm that the tests were carried out in accordance with this Part of this standard. The report shall also state whether or not certificates of sampling, specimen preparation and curing are available. If available, a copy of each certificate shall be provided. 7.2 Information to be provided by the producer of the test specimens for inclusion in the test report 7.2.1 Mandatory information. The following information shall be provided by the producer of the test specimens for inclusion in the test report: a) identification of the test specimen, which preferably should be marked with indelible waterproof ink; b) date of production; c) conditions of storage and curing; d) age of concrete; e) date test required; f) type of density to be measured. 7.2.2 Optional information. If requested the following information shall be provided by the producer of the test specimens for inclusion in the test report: a) building project; b) part or component of the building; c) details of concrete mix. 7.3 Information to be provided by the test laboratory for inclusion in the test report. The following information shall be provided by the test laboratory for inclusion in the test report: a) identification of the test specimen; b) condition of specimen when received (include poor compaction and honeycombing); c) date of receipt of the specimen; d) dimensions of the specimen; e) conditions of storage and curing until test date; f) date of beginning of tests (placing in oven); g) density of the specimen (as-received, saturated or oven-dried and method of determining volume); h) measured absorption; i) corrected absorption; j) details of reinforcement (if any); k) orientation of the specimen to the structure; l) certificate that the test has been carried out in accordance with this Part of this standard; m) other remarks. correction factor volume mm3() surface area mm2()12.5× - -= BS 1881-122:1983 © BSI 12-19983 Figure 1 Correction factor BS 1881-122:1983 4 © BSI 12-1998 Testing concrete Summary of published British Standards Due to the present restructuring of BS 1881 Methods of testing concrete and BS 4408 Recommendations for non-destructive methods of test for concrete, the following information has been published, to help keep readers up-to-date, with the situation so far. (February 1983). BS 1881-1:1970Method of sampling fresh concrete on site Method of mixing and sampling fresh concrete in the laboratory. BS 1881-2:1970Slump test Compacting factor test “V-B” consistometer test Method for determination of weight per cubic metre of fresh concrete Method for determination of air content of fresh concrete Analysis of fresh concrete. BS 1881-3:1970Making and curing test cubes Making and curing no-fines test cubes Making and curing test beams Making and curing test cylinders Method for accelerating the curing of test specimens: 1) the 55 °C method 2) the 82 °C method. BS 1881-5:1970Method for determination of the dynamic modulus of elasticity by an electrodynamic method Method for determination of changes in length of concrete prisms (initial drying shrinkage, drying shrinkage and wetting expansion) Method for determination of initial surface absorption. BS 1881-6:1971Analysis of hardened concrete. BS 1881-114:1983Method for determination of density of hardened concrete. BS 1881-115:1983Specification for compression testing machines for concrete. BS 1881-116:1983Method for determination of compressive strength of concrete cubes. BS 1881-117:1983Method for determination of tensile splitting strength. BS 1881-118:1983Method for determination of flexural strength. BS 1881-119:1983Method for determination of compressive strength using portions of beams broken in flexure (equivalent cube method). BS 1881-120:1983Method for determination of the compressive strength of concrete cones. BS 1881-121:1983Method for determination of static modulus of elasticity in compression. BS 1881-122:1983Method for determination of water absorption. BS 4408-1:1969Electromagnetic cover measuring devices. BS 4408-2:1969Strain gauges for concrete investigations. BS 4408-3:1970Gamma radiography of concrete. BS 4408-4:1971Surface hardness methods of testing concrete. BS 4408-5:1974Measurement of the velocity of ultrasonic pulses in concrete. BS 1881-122:1983 © BSI 12-1998 Publications referred to BS 1881, Testing concrete. BS 1881-114, Method for determination of density of hardened concrete. BS 2648, Performance requirements for electrically-heated laboratory drying ovens. BS 5328, Methods for specifying concrete, including ready-mixed concrete. BS 5497, Precision of test methods1). BS 5497-1, Guide for the determination of repeatability and reproducibility for a standard test method. 1) Referred to in the foreword only. BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BSI Ð British Standards Institution BSI is the independent national body responsible for preparing British Standards. 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