Performance of Paste Phase of Alkali-Activated Composite Produced by Utilizing Fly Ash and GGBS

It takes a lot of energy to produce ordinary Portland cement (OPC), a key component of concrete, which results in a significant amount of carbon dioxide and other greenhouse gases (GHGs) being released into the environment. Alkali-activated composite (AAC) paste phase is a key factor in defining the mechanical characteristics and durability of these environmentally friendly alternative binders. The paste phase in AACs is thoroughly discussed in this work in terms of its composition, microstructure, and performance traits. Investigation is conducted into the effects of numerous variables, such as precursor composition, curing circumstances, alkali activator concentration (in %), on the qualities of the paste phase. Additionally, the microstructural analysis is carried to give light on the mechanisms underlying the AACs’ mechanical toughness and durability. The findings support the development of environmentally friendly and high-performing building materials by advancing our understanding of and ability to optimize the paste phase in AACs. It was determined that the ideal combination for an alkali-activated composite in its wet form was 6% Na₂O and 10% SiO₂. The results observed when the curing temperature was varied from 50 to 90 °C were around 68.06 MPa for 6% of Na₂O content at 70 °C and 70.07 MPa for 10% of SiO₂ content at 90 °C.