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Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
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Home > Tools > Frequently Asked Questions
Q. Are the proportions of ingredients inter-related to produce concrete of a given workability? A. Yes. For example, to maintain the desired slump, the proportion of fine-to-coarse aggregate should be reduced as the cementitious material content is increased, if the w/cm remains the same. If the amount of coarse aggregate and cement are kept constant, but the air content is increased, the volumes of water and fine aggregate would be reduced, thus reducing the w/cm to partially compensate for the strength reduction due to increased air content. References: SP-1(02); ACI PRC-211.1-22; ACI 211.4R-08; ACI PRC-211.7-20; ACI 211.6T-14 Topics in Concrete: Concrete Fundamentals; Mixture Proportioning; Specifications
Q. Are the proportions of ingredients inter-related to produce concrete of a given workability?
A. Yes. For example, to maintain the desired slump, the proportion of fine-to-coarse aggregate should be reduced as the cementitious material content is increased, if the w/cm remains the same. If the amount of coarse aggregate and cement are kept constant, but the air content is increased, the volumes of water and fine aggregate would be reduced, thus reducing the w/cm to partially compensate for the strength reduction due to increased air content.
References: SP-1(02); ACI PRC-211.1-22; ACI 211.4R-08; ACI PRC-211.7-20; ACI 211.6T-14
Topics in Concrete: Concrete Fundamentals; Mixture Proportioning; Specifications
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