Lifecycle assessment analysis of recycled concrete aggregate incorporating fly ash and hemp fiber

The critical roles of recycling are increasing depending on depleted natural resources and its devastating consequences. Concrete has been one of the most used building materials for many years to response the basic need of human beings for shelter. The studies on the recycling of concrete are crucial to minimize negative effects of both the high amount of energy consumed during the production phase and the limited recycling opportunities after destruction. Considering the amount of construction and demolition waste (CDW) after the February 6, 2023 earthquakes in Türkiye, it is clear that recycling concrete (RC) may make a positive contribution to environmental sustainability and natural resources usage. In addition, as a result of the ongoing urban transformation projects throughout Türkiye, especially in Istanbul, there is a need to recycle CDW, the majority of which consists of concrete. This paper examines the equivalent CO2 emissions of recycled concrete aggregate (RCA) incorporation of various proportion fly ash and hemp fiber based on previous studies by applying the Excel-based GreenConcrete LCA software developed at the University of California Berkeley Campus (UC Berkeley). As a result of the investigations, it is seen that the use of RCA, which is generated in large quantities both as a result of earthquakes and urban transformation projects, reflects positively on the environmental impacts in the LCA analysis. In addition, the use of concrete mixtures that contribute to the recycling of wastes such as fly ash and hemp fiber used as admixtures contributes to reducing the environmental damage of these wastes and improving the concrete content such as thermal and structural performances.