【国外标准】 Standard Specification for Production of Dry Cast Concrete Used for Manufacturing Pipe, Box, and Precast Structures

This specification covers the procedures and test methods for the production of dry cast concrete, defined as very low slump or zero-slump concrete that requires continuous and intense vibration, or mechanical means, or a combination of vibration and mechanical means to consolidate the concrete, enabling immediate removal of the forms from the product. The placement, consolidation, curing, or protection of the concrete are not covered by this specification. The aggregates shall be sized, graded, proportioned, and mixed with such proportions of cementitious material, water, and admixtures, if any, to produce a thoroughly mixed concrete of such quality that the precast product will conform to the test and design requirements of the relevant specification. Materials covered by this specification are the following: cementitious materials (cement, slag cement, fly ash), allowable combinations of cementitious materials, aggregates, and admixtures and blends.This specification also covers weigh batching and mixing, volumetric batching and continuous mixing, reporting, and strength of the specimen.1.1 This specification covers the production of dry cast concrete as defined in 3.2.1. Requirements for quality of concrete shall be as hereinafter specified. This specification does not cover the placement, consolidation, curing, or protection of the concrete.1.2 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this 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.