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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. Does the method of molding test specimens affect the test results? A. Yes. Unless specimens are carefully molded, erratic test results will be obtained. The concrete should be placed in the mold in layers; then, each layer should be rodded or vibrated if the slump is 25 mm (1 in.) or greater, and vibrated if the slump is less than 25 mm (1 in.). The mold should be held firmly in a vertical position during filling and stood on a base plate that is a true horizontal plane. Leakage of water from the molded concrete should be avoided. See ASTM C31 and ASTM C192 for guidance on making and curing test specimens in the field and in the laboratory, respectively. References: SP-1(02); ASTM C31; ASTM C192 Topics in Concrete: Testing of Concrete
Q. Does the method of molding test specimens affect the test results?
A. Yes. Unless specimens are carefully molded, erratic test results will be obtained. The concrete should be placed in the mold in layers; then, each layer should be rodded or vibrated if the slump is 25 mm (1 in.) or greater, and vibrated if the slump is less than 25 mm (1 in.). The mold should be held firmly in a vertical position during filling and stood on a base plate that is a true horizontal plane. Leakage of water from the molded concrete should be avoided. See ASTM C31 and ASTM C192 for guidance on making and curing test specimens in the field and in the laboratory, respectively.
References: SP-1(02); ASTM C31; ASTM C192
Topics in Concrete: Testing of Concrete
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