Comparative Study of Waste Glass Powder as Pozzolanic material in Concrete

Glass is used in many forms in day-to-day life. It has limited life span and after use it is either stock piled or sent to landfills. Since glass is non-biodegradable, landfills do not provide an environment friendly solution. Hence, there is strong need to utilize waste glasses. Many efforts have been made to use waste glass in concrete industry as a replacement of coarse aggregate, fine aggregate and cement. Its performance as a coarse aggregate replacement has been found to be non-satisfactory because of strength regression and expansion due to alkali-silica reaction. The research shows that there is strength loss due to fine aggregate substitution also.The aim of the present work was to use glass powder as a replacement of cement to assess the pozzolanic activity of fine glass powder in concrete and compare its performance with other pozzolanic materials like silica fume and fly ash. A series of tests were conducted to study the effect of 15% and 30% replacement of cement by silica fume, fly ash and glass powder on compressive strength and durability in the form of capillary absorption. The particle size effect was evaluated by using glass powder of size 150µm-100µm and glass powder of size less than 100µm. The present study shows that waste glass, if ground finer than 100µm shows a pozzolanic behavior. It reacts with lime at early stage of hydration forming extra CSH gel thereby forming denser cement matrix. The early consumption of alkalis by glass paticles mitigate alkali-silica reaction hence increase durability of concrete