POTENTIAL OF GEOPOLYMER COATING FOR LIGHTWEIGHT AGGREGATE VIA MILLING AND DIPPING METHOD: A REVIEW

The high demand for construction materials and building products, particularly aggregates, necessitates the development of innovative as the natural aggregate resource depletes. Lightweight aggregates are one of the alternatives has meet industry demand with low apparent density, excellent thermal insulation property and fire protection. Unfortunately, lightweight aggregate has a high-water absorption rate, which results in low strength and high porosity. These conditions had a negative impact on the qualities of fresh concrete, such as strength, slump, and cracking. Surface coating is thought to be a good way to prevent water absorption by lightweight particles, which lowers the concrete's performance. To reinforce the concrete, inorganic polymer composite material and cement were commonly employed to coat lightweight particles. The article presents a review on current issues facing by lightweight aggregate, mix proportion of geopolymer coating (aluminosilicate raw materials, alkaline activator ratio) and coating method (milling and dipping). This review has highlighted performance of lightweight aggregate for concrete application can be enhanced by approaching geopolymer coating as surface coating.