The Fracture Characteristics of Crushed Limestone Sand Concrete

Abstract

The use of crushed sand as a fine aggregate has rapidly increased due to a shortage of river sand. Accordingly, research on crushed sand concrete is required. In this research, the fracture characteristics of crushed limestone sand concrete were experimentally investigated through a wedge splitting test, and the results were compared with those of crushed granite sand concrete and river sand concrete. The strength of crushed limestone sand concrete was also investigated. It was shown that the fracture energy of concrete was little influenced by the type of fine aggregate. In addition, the fracture energy of crushed sand concrete was slightly higher than that of river sand concrete. This seems to be due to very fine sand (VFS) included in crushed sand, which tends to improve the cohesion between cement paste and aggregate. Also, the fracture energy was not proportionally increased with an increase of concrete strength. The characteristic length of crushed limestone sand concrete was almost the same as that of river sand concrete or crushed granite sand concrete. The characteristic length greatly decreased as the strength of concrete increased. (C) 1997 Elsevier Science Ltd.