Fly Ash and Silica in Expanded Polystyrene Concrete: Finding the Research Gap

There are various types of lightweight concrete that already exist today. In producing lightweight concrete, the use of added materials in lightweight concrete has been widely studied. Among of those materials, fly-ash and silica based material are commonly being used as additive material in concrete. The purpose of this literature research is to determine the extent of the use of fly-ash and silica in Expanded Polystyrene (EPS) lightweight concrete. From several studies that have been done previously, lightweight concrete from EPS was quite significant to give good results in order to reduce the unit weight of concrete, but has not shown the expected compressive strength results. The literature review method to gather information about the use of fly ash and silica in EPS lightweight concrete will be conducted in a systematic way. Data search was performed on qualified journal databases such as Science Direct and Scopus. The timeframe of journals taken was that published between 2000-2020 to ensure getting the latest research. From the results of observing and searching the article, there were at least two methods of using fly-ash and silica as added material, which were in pure/as-is form (as part of concrete mixture material) and modified form (both modifying the form of fly-ash and silica or as part of modifying the aggregate). The use of fly-ash and silica have shown positive results in improving the quality of lightweight concrete. But from the literature search results, there were still many gaps or things that can be developed and processed to look for other mixed methods and materials. This can increase the ability of fly-ash and silica as an additive material in order to create better EPS lightweight concrete.