Effect of Fly Ash and Metakaolin Substituted Forms on Structural Properties in Light Mortar with Pumice Aggregate

Abstract

In this study, experimental tests were conducted on composite mortars in different forms prepared using lime, pumice, fly ash, and metakaolin. This research aims to recycle fly ash produced as industrial waste and produce a building material that is durable, lightweight, and provides good insulation. In the composite structure mortar mixture designs prepared for the experiments, CEN standard sand was replaced with Nevşehir pumice (0.5-4 mm) at the rates of 10%, 20%, and 30%, respectively, and fly ash-metakaolin was replaced with the cement at the rates of 10%, 20%, and 30%, respectively. A total of 13 different mixtures were prepared. Unit volume mass test, Ultrasonic test, water absorption test, compressive strength test, flexural strength, thermal conductivity coefficient test, scanning electron microscope (SEM) analysis, and thermogravimetric - differential thermal (TGA/DTA) analysis were performed on the prepared samples. As a result of the research, it was determined that the mortar mixture obtained by substituting 30% pumice with standard sand and 30% fly ash and metakaolin with cement provided the highest compressive strength, lowest dry unit volume weight, and thermal conductivity coefficient compared to other mortar mixtures.