Using Recycled Glass in Alkali-Activated Materials

Portland cement-based products, primarily concretes, are the world\u27s most commonly used building materials. However, Portland cement production is characterized by high energy demands, consumption of non-renewable prime materials and the emission of greenhouse gases. Alkali-activated materials (AAMs) constitute a possible alternative to Portland cement due to lower energy demands, lower polluting gas emissions and the absence of durability related technical problems. AAMs is prepared by an alkaline activator and industrial by products such as slag, fly ash and silica fume. The purpose of this study is to examine the use of recycled glass in AAMs production through forming sodium silicate hydrate (waterglass) – a common alkali activator. A series of bench-scale glass dissolution reactions were performed using sodium hydroxide solutions with commercially cleaned and characterized recycled glass. Reactions were performed at 80oC and continuously stirred where all glass particles are suspended. Concentration of dissolved silicon were monitored for every 48 hours for 3 weeks and analyzed using ICP (Inductively Coupled Plasma). Impact of glass particle size and concentration of sodium hydroxide were examined. Highest dissolved silicon concentration was found to be at 70,000 ppm with the finest glass particle size of around 70 µm using 1M sodium hydroxide.https://ir.library.illinoisstate.edu/urshsc/1003/thumbnail.jp