Environmental assessment of supplementary cementitious materials and engineered nanomaterials concrete

Abstract

Concrete has been one of the most common building materials used in construction in the world for many centuries. The manufacturing of concrete plays an important role in the generation of global warming emissions and waste and causes non-renewable resource depletion. This research assesses the environmental impacts of the use of supplementary cementitious materials (SCMs) and engineered nanomaterials (ENMs) (i.e., by-products) as partial replacement of ordinary Portland cement in concrete. It also evaluates the structural performance of the use of construction and demolition waste as partial replacement of natural aggregate in concrete in terms of compressive strength and durability. Results show that the use of SCMs and ENMs reduces the global warming impact (GWI) and the cumulative energy demand (CED) of concrete production without reducing strength and durability. In some cases, it enhances durability and strength. However, there is a tradeoff between durability and strength improvement with the use of reengineered by-products resulting in increased GWI and CED. Although they produce almost the same GWI and CED as those of OPC concrete, improving the use of recycled aggregates as a partial natural aggregate replacement can reduce the use of virgin materials.