LABORATORY AND FIELD TESTS FOR METHODS OF QUALITY CONTROL AND MODIFICATION OF MIX PROPORTIONS FOR CONCRETE IN RCC PAVEMENTS

Abstract

Based on the results of laboratory and field tests for concrete in Roller compacted Concrete Pavements, it was found that:(1) The quality of the fresh concrete can be determined using a slightly modified version of the VC test and the compaction method used for concrete in Roller Compacted Dam concrete.(2) The degree of compaction in speciments for quality control and the actual concrete at site can be determined from the modified VC values.(3) The strength can be determined from the degree of compaction and the water/cement ratio.(4) Among the parameters in mix proportioning, the volumetric water to cement ratio, the ratio of the amount of cement paste to the air voids in the sand, and the ratio of the amount of mortar to the air voids in the aggregate are the ones that affect the modified VC values.From the results of these tests, regression equations are proposed to estimate the consitency and the compressive strength of the concrete when the mix proportion is varied. Also the methods to suitably modify the mix proportion to obtain the concrete of required quality are discussed in this paper.