Effect of the maximum aggregate size on mechanical properties of four-grade RCC

For study the effect of the maximum aggregate size on mechanical properties of four-grade RCC, paper carried out mechanical tests of four-grad and three-grade RCC separately with 120mm and 80mm of the maximum aggregate size, and contrasted corresponding performances of wet screened small specimens(the maximum aggregate size is 40mm). The results shown that from 80mm to 120mm of the maximum aggregate size of RCC, the compressive strengths were no significant change, axial tensile strengths decreased 6%; Contrast full graded to wet screened specimens, compressive strengths of the former were higher 13% ∼ 27%, axial tensile strengths of the former were lower 27%, the similar laws lie in four and three grade concrete. The change of the maximum aggregate sizes produced the difference in mechanical properties of four grade, three grade and wet screened specimens, which was the comprehensive results of positive and negative factors.