Mechanical Properties of Wollastonite and Reclaimed Asphalt Pavement Concrete

Abstract

This study investigates the mechanical properties of concrete incorporating wollastonite powder and reclaimed asphalt pavement (RAP) aggregates. Wollastonite, a calcium metasilicate mineral, was used as a supplementary cementitious material to enhance the durability and sustainability of concrete. RAP, a waste material from asphalt pavement rehabilitation, was utilized as a replacement for natural aggregates. The experimental program involved preparing concrete mixtures with varying percentages of wollastonite powder (0-20%) and RAP (0-30%). The mechanical properties, including compressive strength, tensile strength, and flexural strength, were evaluated. The results showed significant improvements in mechanical properties with the addition of wollastonite powder, attributed to its pozzolanic reactivity and filler effect. The incorporation of RAP aggregates, however, exhibited a decrease in mechanical properties due to the weak bonding between RAP and cement paste. Nevertheless, the combined use of wollastonite powder and RAP resulted in a synergistic effect, offsetting the negative impact of RAP and yielding comparable mechanical properties to control concrete. The optimal mixture exhibited a 25% increase in compressive strength and 30% reduction in carbon footprint. This research demonstrates the potential of wollastonite powder and RAP to develop sustainable and durable concrete, contributing to the reduction of construction waste and environmental impacts. The findings provide valuable insights for the construction industry, promoting the adoption of eco-friendly materials and techniques in infrastructure development.