A study on the use of waste glass in preparing alkali-activated repairing material

Excessive autogenous shrinkage and poor bond performance associated with GGBS-based alkali-activated repairing materials are limiting factors affecting their wide applications. To address these issues, this study focuses on the use of waste glass powder (WGP) as a precursor and glass cullet (GC) as a fine aggregate in preparing alkali-activated repairing mortars (AARMs). The bond strengths and autogenous shrinkages were assessed. Results found that the optimal content of WGP in preparing AARMs was 50% for obtaining a bond strength of 1.70 MPa and shrinkage of about 3500 µstrains. In addition, it was observed that incorporating 50% WGP in combination with GC further decreased the shrinkage compared to the mixture prepared with river sand. Furthermore, the inclusion of 10 wt% MK decreased the flowability and strengths. However, it significantly reduced the autogenous shrinkage (1900 µstrains), producing a compact and intact interfacial bonding zone due to the absence of micro cracking and the presence of N-A-S-H alongside C-A-S-H gels.