The influence of fly ash characteristics as a supplementary cementitious material (SCM) on concrete's mechanical properties

Abstract. The utilization of fly ash as a Supplementary Cementitious Material (SCM) in concrete offers numerous benefits that support sustainable construction. These advantages include reducing CO2 emissions, minimizing waste, enhancing energy efficiency, and lowering costs. Additionally, fly ash can improve the performance of concrete. The characteristics of the fly ash used significantly influence the performance of the resulting concrete. This study aims to evaluate the impact of three types of fly ash used as SCM. The tested fly ash samples originate from three different power plants, namely FA-BSW, FA-BAR, and FA-PLN. Testing was conducted by creating concrete mixtures using variations of these three fly ash sources and comparing them with a control concrete mixture using ordinary Portland cement (OPC), labeled as FA-0. Workability was measured through slump tests on fresh concrete, while dry density and compressive strength were evaluated on hardened concrete specimens (100 mm x 200 mm cylinders) at 3, 7, 28, and 56 days. Additionally, the Strength Activity Index (SAI) was analyzed to assess the pozzolanic activity of the fly ash relative to OPC. The findings from this study are intended to provide valuable insights into the characteristics and performance of these three fly ash types in concrete, as well as their influence on the mechanical properties of the material.