1、 ISO 2015 Testing of concrete Part 12: Determination of the carbonation resistance of concrete Accelerated carbonation method Essais du bton Partie 12: Dtermination de la rsistance du bton la carbonation Mthode de carbonation acclre INTERNATIONAL STANDARD ISO 1920-12 First edition 2015-05-15 Referen
2、ce number ISO 1920-12:2015(E) ISO 1920-12:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electroni
3、c or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier,
4、 Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO 1920-12:2015(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Principle 2 5 Reagents and apparatus . 2 6 Preparation of specimens . 3 6.1 General . 3 6.2 M
5、aking, curing, and testing of prisms and cubes 3 7 Carbonation depth measurements 5 7.1 Exposure period and generation of colour change 5 8 Determination of the carbonation depth 5 8.1 General . 5 8.2 Measuring the depth of carbonation 5 8.3 Appreciation of dense aggregates 5 8.4 Appreciation of por
6、es and porous aggregates and extreme values . 6 8.5 Expression of the results 7 9 Test report . 7 10 Precision . 7 Annex A (informative) Guidance on suitable storage chambers . 8 ISO 2015 All rights reserved iii Contents Page ISO 1920-12:2015(E) Foreword ISO (the International Organization for Stand
7、ardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right
8、to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures u
9、sed to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules
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12、n the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is
13、ISO/TC 71, Concrete, reinforced concrete and pre-stressed concrete, Subcommittee SC 1, Test methods for concrete. ISO 1920 consists of the following parts, under the general title Testing of concrete: Part 1: Sampling of fresh concrete Part 2: Properties of fresh concrete Part 3: Making and curing t
14、est specimens Part 4: Strength of hardened concrete Part 5: Properties of hardened concrete other than strength Part 6: Sampling, preparing and testing of concrete cores Part 7: Non-destructive tests on hardened concrete Part 8: Determination of dr ying shrinkage of concrete for samples prepared in
15、the field or in the laborator y Part 9: Determination of creep of concrete cylinders in compression Part 10: Determination of static modulus of elasticity in compression Part 11: Determination of the chloride resistance of concrete, unidirectional diffusion Part 12: Determination of the carbonation
16、resistance of concrete Accelerated carbonation methodiv ISO 2015 All rights reserved ISO 1920-12:2015(E) Introduction Ferrous steel reinforced concrete structures need to be durable to ensure that the intended service life is achieved. The corrosion of reinforcement induced by carbonation can play a
17、 significant role in the serviceability of a structure and consequently carbonation resistance of concrete is an important property to measure. This International Standard sets out a test method that may be applied to cast test specimens to assess the potential carbonation resistance properties of a
18、 concrete mix. ISO 2015 All rights reserved v Testing of concrete Part 12: Determination of the carbonation resistance of concrete Accelerated carbonation method 1 Scope This procedure is a method for evaluating the carbonation resistance of concrete using an accelerated carbonation test. After a pe
19、riod of preconditioning, the test is carried out under controlled exposure conditions using an increased level of carbon dioxide to which, the vertical sides of the specimen are exposed. The test results are not designated to set performance requirements but to compare the carbonation resistance of
20、different concretes of the same strength class, which are used in the same environmental conditions. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cite
21、d applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 1920-2, Testing of concrete Part 2: Properties of fresh concrete ISO 1920-3, Testing of concrete Part 3: Making and curing test specimens ISO 1920-4, Testing of concrete Part 4: S
22、trength of hardened concrete 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions apply. 3.1 depth of carbonation depth as measured using a phenolphthalein solution sprayed on a freshly-split concrete surface 3.2 single point carbonation depth depth of ca
23、rbonation measured at a single point on a specimen, d k,point 3.3 specimen face carbonation depth mean depth of carbonation of a single exposed face of a single specimen, d k,face 3.4 specimen carbonation depth mean depth of carbonation of a single specimen, d k,spec 3.5 mean carbonation depth mean
24、depth of carbonation of two specimens, d k INTERNATIONAL ST ANDARD ISO 1920-12:2015(E) ISO 2015 All rights reserved 1 ISO 1920-12:2015(E) 4 Principle Two concrete cubes are cast and cured for 28 d in accordance with ISO 1920-3 (see also changes to the curing conditions in 6.2). The two concrete cube
25、s are then conditioned in a laboratory air environment for 14 d prior to sealing the top, bottom, and two opposite side faces. After sealing of all but two faces, the cubes are placed in a storage chamber meeting the conditions specified in 5.4 and having a carbon dioxide level of (3,0 0,5) % for a
26、period of 70 d. After 70 d of exposure, the cubes shall be split in half, perpendicular to the exposed faces, and the depth of carbonation measured in accordance with the procedure given in Clause 7. The test under reference conditions takes therefore a minimum of 112 d, period that comprises a mini
27、mum age of the specimen of 28 d prior to conditioning, a minimum conditioning period of 14 d, and a minimum exposure to increased carbon dioxide levels of 70 d. In case where a higher range of additions such as pozzolanic materials, slag, and others are used, extended curing and drying times are all
28、owed and the same should be reported. If required, further cubic specimens may be casted and used for measurement of the depth of carbonation at exposure periods other than 70 d. Each cubic specimens shall be used for testing at one period of exposure only. When the purpose of the test is to measure
29、 the depth of carbonation on the same specimen at more than one exposure period, concrete prisms shall be used. In this case, two prisms are cast and cured for 28 d in accordance with ISO 1920-3 (see also amendments of the curing conditions in 6.2). The prisms are conditioned in a laboratory air env
30、ironment for 14 d prior to sealing the top, bottom, and two end faces. After sealing all but two longitudinal faces, the prisms are placed in a storage chamber, meeting the conditions specified in 5.4 and having a carbon dioxide level of (3,0 0.5) % for the overall test period which should be 70 d.
31、After each exposure period, a 50 mm slice is broken from each prism and tested for carbonation depth. After splitting off a slice, the split end faces of the prisms are sealed and the remainder of the prisms returned to the storage chamber. The specimens, cubes, or prisms shall be positioned with th
32、eir exposed faces in the vertical position. The curing conditions may vary from one country to another in accordance with local provisions; however, these conditions shall be recorded and reported. 5 Reagents and apparatus 5.1 P ar affin w ax or equi v alent, for sealing the non-exposed faces of tes
33、t specimens. 5.2 A solution, made of 1 g of phenolphthalein powder dissolved in 100 ml solution composed of 70 ml ethanol and 30 ml of deionised water. 5.3 A magnifier and a g auge, to measure the depth of carbonation perpendicular to the exposed concrete surface with a precision of 0,5 mm. 5.4 A st
34、orage chamber with a carbon dioxide concentration at (3,0 0,5) % by volume, temperature at (22 2) C, and a relative humidity at (55 5) %, see Annex A for details of a suitable chamber. In hot climate locations, the conditions in the storage chamber may be temperature at (27 2) C and relative humidit
35、y at (65 5) %. Experience has shown that if saturated surface-dry specimens are placed in the storage chamber shortly after removal from water curing, the relative humidity could exceed that permitted. Also, in storage chambers without active control of the carbon dioxide, the levels could drop belo
36、w the permitted tolerance as the carbonation process continues. It is therefore a recommendation of this test method that the storage chamber has active control on carbon dioxide, relative humidity, and temperature.2 ISO 2015 All rights reserved ISO 1920-12:2015(E) Other carbon dioxide concentration
37、 levels, other humidity levels, and other temperature levels may be used. However, this shall be recorded and reported. NOTE Relative humidity levels may be maintained using methods at the discretion of the laboratory, for example, active humidification/dehumidification or saturated salt solutions.
38、5.5 Apparatus, for recording the relative humidity with a precision of 2,0 % and the temperature with a precision of 0,5 C. 5.6 Apparatus, for recording CO 2concentration with a precision of 0,1 % by volume. It is recommended that recording apparatus be fitted with an audio/visual alarm to alert bre
39、aches of CO 2concentration within the storage chamber due to possible apparatus malfunction. 5.7 Fans, to facilitate steady circulation of air within the storage chamber. 6 Preparation of specimens 6.1 General Cubes and/or prisms for the determination of the carbonation resistance shall be made in a
40、ccordance with this part of ISO 1920. If the specimens are to be made by a test laboratory, the test laboratory shall be supplied with a full specification including the mix quantities and the mixing procedure, and where appropriate, the constituent materials. Where the specimens are prepared by the
41、 client or their representative, the test laboratory shall be informed of the day of casting and provided with a confirmation that the specimens were stored as required by this part of ISO 1920. For the determination of the depth of carbonation at any given exposure period, two cubic specimens havin
42、g a cross-section of 100 mm or greater shall be prepared. For the determination of the depth of carbonation at more than one exposure period on the same test specimen, two prisms, 400 mm long and having a cross-section of 100 100 mm, shall be prepared. The shortest dimension of the specimen, cube, o
43、r prism, shall not be less than four times the maximum nominal upper aggregate size. The use of mould release agents should be avoided or minimized, as they might influence the carbonation depth. 6.2 Making, curing, and testing of prisms and cubes Before casting the specimens, measure the consistenc
44、e class or target value using the slump test, Vebe test, degree of compactability, or flow table test (as appropriate), as described in ISO 1920-2. For each mix, cast two prisms/cubes from a single batch of concrete. Cast the prisms horizontally according to ISO 1920-3. In hot climate locations, the
45、 curing conditions after demoulding the specimen can be different from those mentioned in ISO 1920-3. In this case, the specimens shall be stored in water or in a chamber having a temperature in the range of (27 2) C and a minimum relative humidity of 95 %. After finishing the prisms/cubes, cover th
46、e exposed surface with polythene or similar impermeable sheeting to prevent drying. After (22 2) h, the moulds shall be stripped and the prisms/cubes transferred without delay into a water-filled bath with temperature control set in the range of (20 2) C in accordance with ISO 1920-3. In hot climate
47、 locations, the temperature of the water in the bath may be in the range of (27 2) C. It is recommended that at least two compressive strength specimens are made and tested in accordance with ISO 1920-4 at 28 d. Where a number of mixes are made, additional testing, e.g. the 28-day strength, should b
48、e undertaken to confirm consistent manufacture or identify anomalous batches where mixes might need to be repeated. After removal from the curing tank, the specimens shall be immediately wrapped and sealed in polythene or similar material that will prevent drying during transportation. Alternatively
49、, they should be transported while remaining fully immersed in water, e.g. in a mobile curing tank. On arrival at the test laboratory, the test specimens shall be unwrapped, checked for damage, and then stored in a water-filled ISO 2015 All rights reserved 3 ISO 1920-12:2015(E) curing tank with temperature in the range of (20 2) C in accordance with ISO 1920-3 until they are 28 d old. In hot climate locations, the temperature of the water in the bath may be in the range
