1.1 本实施规程涵盖了根据实施规程模制的混凝土圆柱体试验用无粘结帽盖系统的要求 C31/C31M 或 192/C192M ，或根据试验方法获得的岩芯 C42/C42M 。 允许使用规定硬度的无粘结氯丁橡胶帽进行规定最大重复使用次数的测试，而无需进行达到特定混凝土抗压强度水平的资格测试。超过该强度，水平氯丁橡胶帽将需要资格测试。无论混凝土强度如何，除氯丁橡胶外的所有弹性材料都需要进行鉴定测试。 1.2 抗压强度低于10 MPa[1500 psi]或高于80 MPa[12000 psi]的混凝土的验收试验不得使用无粘结帽。 1.3 本标准的文本是指提供解释性材料的注释和脚注。这些注释和脚注（不包括表和图中的注释和脚注）不应被视为本标准的要求。 1.4 单位-- 以国际单位制或英寸磅单位表示的数值应单独视为标准。每个系统中规定的值不一定是完全相等的；因此，为了确保符合标准，每个系统应独立使用，并且两个系统的值不得组合。 将两个系统的值合并可能导致不符合标准。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 ( 警告-- 用无粘结帽测试的混凝土试件比用粘结帽进行测试的类似试件破裂更剧烈。建议采用《骨料和混凝土测试手册》中给出的安全预防措施。 2. ) 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ===意义和用途====== 4.1 本规程规定在测试根据规程制造的硬化混凝土圆柱体时使用无粘结压盖系统 C31/C31M 或 192/C192M ，或根据试验方法获得的岩芯 C42/C42M 代替实践中描述的封盖系统 C617/C617M 。 4.2 弹性垫在初始载荷下变形，以符合试样端部的轮廓，并通过板和金属环防止过度横向扩展，以使载荷从试验机的支承块均匀分布到混凝土或砂浆试样的端部。

1.1 This practice covers requirements for a capping system using unbonded caps for testing concrete cylinders molded in accordance with Practice C31/C31M or C192/C192M , or cores obtained in accordance with Test Method C42/C42M . Unbonded neoprene caps of a defined hardness are permitted to be used for testing for a specified maximum number of reuses without qualification testing up to a certain concrete compressive strength level. Above that strength, level neoprene caps will require qualification testing. Qualification testing is required for all elastomeric materials other than neoprene regardless of the concrete strength. 1.2 Unbonded caps are not to be used for acceptance testing of concrete with compressive strength below 10 MPa [1500 psi ] or above 80 MPa [12 000 psi]. 1.3 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. 1.4 Units— The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. Combining values from the two systems may result in non-conformance with the standard. 1.5 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. ( Warning— Concrete specimens tested with unbonded caps rupture more violently than comparable specimens tested with bonded caps. The safety precautions given in the Manual of Aggregate and Concrete Testing are recommended. 2 ) 1.6 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. ====== Significance And Use ====== 4.1 This practice provides for using an unbonded capping system in testing hardened concrete cylinders made in accordance with Practices C31/C31M or C192/C192M , or cores obtained in accordance with Test Method C42/C42M in lieu of the capping systems described in Practice C617/C617M . 4.2 The elastomeric pads deform in initial loading to conform to the contour of the ends of the test specimens and are restrained from excessive lateral spreading by plates and metal rings to provide a uniform distribution of load from the bearing blocks of the testing machine to the ends of the concrete or mortar specimens.