The use of building rubbles in concrete and mortar

Abstract

The main components of building rubble collected from demolished structures are waste concrete, brick and tile. A series of experiments using recycled aggregates of various compositions from building rubble were conducted. The test results show that building rubble can be transformed into useful recycled aggregate through proper processing. When the recycled aggregate was washed, the negative effects on the recycled concrete were greatly reduced. This is especially meaningful for flexural strength. Recycled coarse aggregate is the weakest phase given a low water/cement ratio. This effect will dominate the mechanical properties of recycled concrete. On the contrary, using recycled aggregate in concrete has little effect on its mechanical properties if the water/cement ratio is high. This mechanism does not occur in recycled mortar. The quantity of recycled fine aggregate will govern the mortar strength reduction percentage. Although using brick and tile in concrete will affect its mechanical properties, the effect is limited.