The effect of fly ash aggregate produced by cold bonding method on mortar properties

ABSTRACT THE EFFECT OF FLY ASH AGGREGATE PRODUCED BY COLD BONDING METHOD ON MORTAR PROPERTIES NAZMİYE KELEŞ MSc Thesis in Civil Engineering Supervisor: Prof. Dr. Niyazi Uğur KOÇKAL June 2023; 76 pages Fly ash, produced annually by burning 45 million tons of coal in Turkey, is a major source of economic and environmental problems (Guler et al. 2005). Fly ash particles released into the atmosphere during combustion are hazardous to the environment. As such, using fly ash as a recycled material has become increasingly popular over time due to its potential for reducing natural resource consumption and lightening mortar production aggregates. Unfortunately, though, utilization rates of fly ash in our country remain low despite its positive properties; therefore, more comprehensive research should be conducted on how best to utilize this resource within the construction sector before further damage is done to our environment. This study investigated the effect of using aggregates in mortar production by applying the cold bonding method with fly ash obtained from Seyitömer Thermal Power Plant to 40x40x160mm prismatic samples. The physical and mechanical tests conducted on these samples included spreading diameter, unit volume weight determination, bulk density, apparent void ratio, water absorption, capillarity compressive strength and bending tensile strength. Results showed that aggregate production was successful when utilizing this method and that it had a positive impact on mortar production. The test results indicate that, although the compressive strength decreased with an increase in fly ash aggregate ratio, the specific compressive strength increased. This demonstrates that fly ash aggregate is a durable material under high pressure loads and can be used as a suitable replacement for traditional materials such as cement or fine aggregate. Furthermore, this could lead to cost savings due to its lower production costs compared to other construction materials. According to this study, the use of fly ash, an industrial waste, as a recycling material in the building industry, has been shown to reduce environmental pollution, produce lighter concrete, and utilize fewer natural resources. KEYWORDS: Cold bonded fly ash aggregate, Fly ash, Lightweight aggregate, Mortars, Seyitömer thermal power plant.