Effect of Fly Ash and Fine-Sand Addition on the Mechanical and Thermal Properties of Modified Adhesive

Abstract

This study presents an exploratory investigation into the mechanical and thermal properties of a modified adhesive (high adhesive, Sikadur®-330) when mixed with fly ash or a combination of fly ash and fine-sand at various ratios, as well as the adhesive's performance under high temperatures of 250℃. A series of physical tests, including compressive strength, consistency, modulus of rupture, density, and ultrasonic pulse velocity, were conducted alongside thermal assessments, such as final and initial shrinkage, linear expansion coefficient, and heat of reaction measurements. The results demonstrate that the incorporation of fly ash and fine-sand significantly enhances the adhesive's thermal properties by reducing both final and initial shrinkage, minimizing the linear expansion coefficient, and attenuating the heat of reaction. Furthermore, the mechanical properties of the adhesive were observed to improve upon exposure to high temperatures of 250℃. The addition of fine-sand and fly ash to the adhesive not only reduced costs but also led to a notable increase in the modulus of rupture and compressive strength. Consequently, the optimal ratio of adhesive, sand, and fly ash was determined to be 1:1:1 by weight, considering improvements in mechanical and thermal properties, cost reduction, and preserved workability.