Sustainable approach for recycling construction and demolition waste into building material in Tanzania

Abstract

Because it is desired to achieve sustainability in the construction industry, the recycled products should not only be measured by production costs, but by using economic, social and environmental criteria. Knowledge on how to precisely determine the sustainability of recycled building materials is still limited because most of the available sustainability assessment tools are developed to evaluate whole building components. This paper aims at investigating the possibility of recycling the construction and demolition (C&D) waste (mainly cementitious rubble) into building material such as concrete blocks that meet the requirements for structural walls in Tanzania in a sustainable manner. A sustainability tool was applied to determine which of the recycling recipes used to produce the qualified concrete blocks was sustainable. The findings showed the recipe which used sisal fibers (i.e., 0.25% amount of cement) in 100% recycled aggregates from C&D waste for concrete block production was found to be a more sustainable recipe than the others. This condition suggests that using 100% C&D waste into building materials contributes in conservation of resource of relatively the same amount of natural aggregates for future use which is in line with the sustainable construction concept. Therefore, it is possible to recycle 100% C&D waste into building materials in Tanzania using sisal fibers which are the locally produced materials.

Keywords: Sustainable construction, recycling, C&D waste, building material, Tanzania