Controlling fresh properties of self-compacting concrete containing waste glass powder and its influence on strength and permeability

Abstract

Adjustment of superplasticizer (SP) dosage is one of the main factors in proportioning of self-compacting concrete (SCC) mixtures. The quantity of SP has to be within certain limits to avoid segregation or bleeding, which otherwise could alter the microstructure of concrete and affect its performance in the longer-term. Since SCC is produced with high cement content, some issues, such as high costs, environmental impacts due to natural resource depletion and carbon dioxide emissions associated with cement production, can arise. Utilization of recycled waste materials as cement replacements can be an effective solution to some of these issues. The aim of the present study was to investigate the effects of SP dosages on SCC containing waste glass powder of various sizes as cement substitutes, to study the variations in strength and durability. Three glass size ranges (10 µm, 20 µm and 40 µm) were compared. The results indicate that increase in SP dosage beyond a certain limit deteriorates concrete performance in terms of strength and oxygen permeability. The influence of SP on the performance of SCC containing coarser glass was insignificant as compared to finer glass SCC samples. 10 µm glass substituted at a 30% replacement rate showed the most comparable results to class F fly ash concrete.