Effect of grain-size distribution of sand on the properties of fine-graded concrete

Abstract

The effect was investigated of the grain-size distribution of 3 sand types on the cement consumption in fine-graded concrete, on its strength properties, frost resistance, and water absorption. The study indicates that a 5 to 10-12% content of sand grains less then 0.14 mm in diameter should be taken as the optimum quantity. Details are given of the tests in which sand was dispersed in fractions which were than blended in the desired proportions. They were then compacted into a cube measuring 10 x 10 x 10 cm on a vibration table to determine porosity in the compacted state. The lowest porosity in the vibro-compacted state was observed in the medium sand, while coarse and fine sand exhibited nearly identical porosity. The compositions of the concrete mixes were calculated, and the compression strengths were determined at 3, 28, and 180 days. Analysis indicated that concrete comprising all 3 sand types and aged 180 days has nearly identical compression and tensile strength, but a difference was observed in the flow rate. The results are also given of 200 alternate freezing and thawing cycles, analysis of change in workability factor, investigations of the physico-mechanical properties, and watertightness factor.