This document summarizes a study that used fine quarry dust, a waste material from M-sand industry, to stabilize expansive black cotton subgrade soil. Key findings include:
1) When 50% of fine quarry dust is mixed with subgrade soil, the soil classification changes from highly expansive (CH) to low compressibility (CL), indicating reduced expansiveness.
2) Mixing 50% fine quarry dust decreases the subgrade soil's liquid limit, plastic limit, plasticity index, and differential free swell, further demonstrating reduced expansiveness.
3) Mixing 50% fine quarry dust increases the maximum dry density and soaked CBR of the subgrade soil. CBR