Utilization of fly ash cenosphere to study mechanical and thermal properties of lightweight concrete

Abstract

The utilization of cenosphere by-product of fly ash as a substitution of sand in concrete is an effective way to reduce thermal conductivity. This study investigates the mechanical and thermal properties of cenosphere substituted in the lightweight concrete. Cenosphere is the recycled material and possesses good thermal insulation properties. Study objectified replacement of sand over the FA cenospher to study the mechanical and thermal properties of the concrete. Experimental setup of the study 10%, 20% and 30% sand by weight is replaced with cenosphere. Concrete specimen prepares and cured for the period of 3, 7 and 28 d. Compressive strength of the concrete is analyzed for 3-7 and 28 d where tensile strength is analyzed for 28 d. Study shows significant improvement in the compressive strength and tensile strength. Thermal conductivity is analyzed for 28 d cured concrete samples using Heat flow FOX-50 instrument. Thermal conductivity reduces by 35% with the replacement of 30% sand over cenosphere which shows the significant reduction. Due to the lower density of cenosphere density of concrete samples reduced which is one of the leading factors to the lower thermal conductivity. Study concluded by replacement of 30% FA cenosphere compressive strength increased conversely thermal conductivity and density of the concrete specimen has reduced.

Keywords

• fly ash cenosphere
• compressive strength
• tensile strength
• thermal conductivity
• density
• lightweight concrete