Influence of aggregate type on mechanical behavior of normal- and high-strength concretes

Effects of aggregate type on the mechanical properties of both normal- and high-strength concretes were investigated under compressive loading. Basalt, sandstone, and Triassic and Devonian crushed limestone coarse aggregates were used in the concretes. For each coarse aggregate type, six concrete mixtures were made with the same portland cement and natural sand. In each concrete class, nominal slump, effective water-cement ratio, and cement content were kept constant. In all concrete mixtures, the grading and maximum particle size were the same. In low- or moderate-strength concretes, Triassic limestone containing concrete had the highest compressive strength. In high- strength concretes, however, the compressive strength of basalt containing concrete had the highest value. In high-strength concretes, the hysteresis loops of Triassic and Devonian lime- stone concretes are generally narrower than those of basalt and sandstone concretes. It can be concluded that the irreversible energy up to prepeak stress in compression decreases significantly and the loop becomes narrower with an increase in compressive strength. The brittleness index increases substantially with the compressive strength of concrete.