定价： 515元 加购物车

定价： 590元 加购物车

定价： 515元 加购物车

定价： 590元 加购物车

4.1 Two types of alkali reactivity of aggregates have been described in the literature: the alkali-silica reaction involving certain siliceous rocks, minerals, and artificial glasses (1),3 and the alkali-carbonate reaction involving dolomite in certain calcitic dolomites and dolomitic limestones (2). This test method is not recommended as a means to detect combinations susceptible to expansion due to alkali-silica reaction since it was not evaluated for this use in the work reported by Buck (2). This test method is not applicable to aggregates that do not contain or consist of carbonate rock (see Descriptive Nomenclature C294).4.2 This test method is intended for evaluating the behavior of specific combinations of concrete-making materials to be used in the work. However, provisions are made for the use of substitute materials when required. This test method assesses the potential for expansion of concrete caused by alkali-carbonate rock reaction from tests performed under prescribed laboratory curing conditions that will probably differ from field conditions. Thus, actual field performance will not be duplicated due to differences in wetting and drying, temperature, other factors, or combinations of these (see Appendix X1).4.3 Use of this test method is of particular value when samples of aggregate from a source have been determined to contain constituents that are regarded as capable of participation in a potentially deleterious alkali-carbonate rock reaction either by petrographic examination, Guide C295/C295M, by the rock cylinder test, Test Method C586, by service record; or by a combination of these.4.4 Results of tests conducted as described herein should form a part of the basis for a decision as to whether precautions be taken against excessive expansion due to alkali-carbonate rock reaction. This decision should be made before a particular cement-aggregate combination is used in concrete construction (see Note 1).NOTE 1: Other elements that may be included in the decision-making process for categorizing an aggregate or a cement-aggregate combination with respect to whether precautions are needed, and examples of precautions that may be taken, are described in Appendix X1.4.5 While the basic intent of this test method is to develop information on a particular cement-aggregate combination, it will usually be very useful to conduct control tests in parallel using the aggregate of interest with other cements or the cement of interest with other aggregates.1.1 This test method covers the determination, by measurement of length change of concrete prisms, the susceptibility of cement-aggregate combinations to expansive alkali-carbonate reaction involving hydroxide ions associated with alkalies (sodium and potassium) and certain calcitic dolomites and dolomitic limestones.1.2 The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.1.3 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. When combined standards are cited, the selection of measurement system is at the user's discretion subject to the requirements of the referenced standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 加购物车

定价： 646元 加购物车

定价： 571元 加购物车

定价： 590元 加购物车

定价： 646元 加购物车

定价： 646元 加购物车

定价： 646元 加购物车

定价： 646元 加购物车

定价： 646元 加购物车

3.1 This test method provides a means of assessing the sulfate resistance of mortars made using portland cement, blends of portland cement with pozzolans or slags, and blended hydraulic cements. Test Method C452 is suitable for evaluating portland cements but not blended cements or blends of portland cement with pozzolans or slags.3.2 The standard exposure solution used in this test method, unless otherwise directed, contains 352 moles of Na2SO4 per m3 (50 g/L). Other sulfate concentrations or other sulfates such as MgSO4 may be used to simulate the environmental exposure of interest. Further discussion of these and other technical issues is given in the Appendix.1.1 This test method covers the determination of length change of mortar bars immersed in a sulfate solution. Mortar bars made using mortar described in Test Method C109/C109M are cured until they attain a compressive strength of 20.0 ± 1.0 MPa [3000 ± 150 psi], as measured using cubes made of the same mortar, before the bars are immersed.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 加购物车

定价： 646元 加购物车