Accession Number : AD0252861

Title :   PLASTIC CONCRETE QUALITY CONTROL

Corporate Author : NAVAL CIVIL ENGINEERING LAB PORT HUENEME CA

Personal Author(s) : LORMAN, WILLIAM R.

Report Date : 31 JAN 1961

Pagination or Media Count : 79

Abstract : The basic philosophy is presented for controlling the uniformity of concrete during the mixing phase. The quality of fresh concrete is fixed by 3 principal features: mixing water, mix proportions, and aggregate ratios. The primary factors complementing the 3 principal features are: cement content, water-cement ratio, workability, and unit weight. The highlights of testing methods which hold appreciable promise and various associated approaches are discussed. Three tests (slump, compacting factor, and slope) are recommended for workability measurement and each is compatible with water content of the mix under consideration. Strength is predictable by means of empirical expressions relating watercement ratio to compressive strength and correlating these with flexural strength. Watercement ratio of fresh concrete, intended to conform to a predetermined mix design, could be corroborated by electrical resistance methods. Determination of water-cement ratio of any fresh concrete, of unknown mix design, could be determined in about a half hour by Dunagan's analytical procedure. Other methods involving neutron attenuation and X-ray spectrometry for ascertaining the water-cement ratio of any fresh concrete mix appear promising and presumably could be accomplished in less than 10 minutes. A selected bibliography of more than 500 items traces developments, during the past 60 years, in this area of concrete quality control. (Author)

Descriptors :   *BIBLIOGRAPHIES, *CONCRETE, CEMENTS, MECHANICAL PROPERTIES, MIXTURES, PHYSICAL PROPERTIES, PLASTIC PROPERTIES, QUALITY CONTROL, TEST METHODS, WATER.

Distribution Statement : APPROVED FOR PUBLIC RELEASE