The potential of ground clay brick to mitigate Alkali–Silica Reaction in mortar prepared with highly reactive aggregate

• A brief study has been done to evaluate the pozzolanic reactivity and ASR mitigation performance of ground crushed brick.
• A brief study has been done to evaluate the effect of ground crushed brick fineness on ASR mitigation performance.
• Microscopic analysis has been conducted to evaluate the microstructure of the mortar containing ground crushed brick.
• A comparison has been made to investigate the pozzolanic reactivity of ground crushed brick using XRD analysis.

The objective of this work was to study the effect of ground clay brick on mitigating the Alkali Silica Reaction (ASR) in mortar bars prepared with highly reactive aggregates. To evaluate the potential of ground crushed clay brick to mitigate ASR distress in mortar, mortar bars and mortar cubes were cast with combination of different dosages of ground clay brick (partial replacement of portland cement). The pozzolanic reactivity of ground clay brick was also evaluated using strength activity index test. In addition, the Scanning Electron Microscopy (SEM) and the Energy-Dispersive X-ray Spectroscopy (EDS) were conducted to evaluate the microstructure and location of the ASR gel and its chemical composition. The results from this study indicated satisfactory level of pozzolanic reactivity when cement was partially replacement by the ground clay brick. Also, it was found that replacing 25% of cement with ground clay brick (by weight) could significantly decrease the ASR expansion by 67% at the age of 14 days. However, this study suggested that the compressive strength values of the specimens containing higher dosages of ground crushed brick (i.e. 50% replacement level) were significantly lower than that of the control specimens.