Fracture behaviour of concrete containing limestone fines

摘要

The use of limestone fines as partial replacement of cement can lower the cost of concrete, protect the environment by reducing carbon dioxide emissions and thus contribute towards sustainable development. The effect of incorporating limestone fines on the mechanical and durability properties of mortar and concrete has been thoroughly investigated. However, little research has been done so far on the fracture behaviour of mortar and concrete beams containing limestone fines. In the present study, the effect of limestone as partial replacement of cement on strength and fracture behaviour of mortar and concrete was investigated. This was carried out experimentally by determining the load-deflection curves of concrete or mortar using the three-point flexural tests on notched samples so that the material characteristics at rupture, such as the fracture energy G_F and fracture toughness, K_I (stress intensity factor) for mode I of fracture could be deduced. The results showed that strength and fracture parameters were reduced with the increase of limestone fines in cement for both notched mortar and concrete beams.