On the hygrothermal behavior of concrete containing glass powder and silica fume

In this work, the effect of the partial replacement of cement by alternatives derived from waste glass and silica fume on the hygrothermal behavior of concrete was investigated. For this purpose, concretes containing 20% and 30% of glass powder (GP) have been tested. In addition, two concretes containing the same replacement ratios of GP and 5% of silica fume (SF) were also manufactured. The mixtures were characterized in terms of workability, compressive strength, microstructure and hygrothermal properties. The results show that the use of 20% and 30% of GP improves the consistency of the concrete in the fresh state by 41% and 55%, respectively. In the hardened state, the use of GP engenders an increase in porosity and slightly affects the pore size distribution. However, the SF reduces the critical diameter and creates a range of micropores. Despite the decrease of compressive strength with increasing GP ratio, the concrete exhibits satisfactory performance for structural application at both 28 days (36-41 MPa) and 91 days (40-45 MPa). The cement substitution by 30% of GP and 5% of SF highlights a decrease in thermal conductivity and the specific heat of about 17% and 2.3%, respectively. The water vapor permeabilities of the concrete used ranged from 2.07e-12 to 4.74e-12 kg/m.s.Pa.

Automated summary

This study found that partial replacement of cement can improve the consistency and compressive strength of concrete, affecting pore structure and hygrothermal properties. Additionally, the use of glass powder and silica fume can reduce thermal conductivity and increase specific heat of concrete.