Durability of Lightweight Concrete with Expanded Glass and Silica Fume

Although concrete has a significant environmental impact, it also offers interesting opportunities of recycling waste materials that may improve its sustainability. Together with different other industrial residues that are normally recycled in concrete, expanded glass can be used as a lightweight aggregate. However, the use of glass in concrete raises concerns about durability because of its poor stability in alkaline environments. This paper presents a study aimed at investigating the durability of lightweight concrete (LWC) made with expanded glass and silica fume used, respectively, for the replacement of the fine fraction of aggregate and as mineral addition. Expanded glass particles were characterized in terms of alkali-aggregate reaction, density, absorption, and microstructure. The combination of expanded glass and silica fume led to a structural lightweight concrete that was able to maintain its strength under exposure to moist and hot conditions and showed high resistance to the penetration of aggressive agents.