Estudo da influência de adições no módulo de elasticidade dinâmico, na resistência à fadiga e na tenacidade à fratura para concretos convencionais

Abstract

In Brazil most used the industrial wastes as concrete additions are the blast furnace slag finely ground to an amorphous state and the silica fume. Recently, wastes from civil construction, specially the red ceramics, have been evaluated as possible concrete constituents. These materials act like cements or pozolanic material. They change the strength evolution of concrete with the cure time as well as the concrete durability.However, then are few studies on the effect of these additions on bending, Young modulus, fracture energy and static fatigue. In this paper these mechanical properties are analyzed in concrete with various additions of silica fume, granulated blast furnace slag and red ceramic waste. The addition of 5% of silica is more effective than the addiction of 10% as a hardening agent, of the first hardening stages. In general the studied additions do not seem to affect the elasticity modulus on the first 28 days. The additions of 10% of silica fume, slag and red ceramic tend to decrease significantly the bending strength. The concrete without addition and with addition of 5% of silica fume shows sensitivity to cyclic efforts. The fracture energy is not affected by the additions and not even by the factor water cement.