Improvement of engineering properties of expansive soil using liming leather waste ash

The expansive soils have always presented various challenges for geotechnical and civil engineers due to their low bearing capacity and high swell-shrinkage characteristics. This study aims to utilize liming leather waste ash (LLWA) as a sole expansive soil stabilizer examining its effects on various engineering properties of soil such as consistency limits, compaction parameters, unconfined compressive strength (UCS), California bearing ratio (CBR), and swell parameters. The observations are also made on the curing effects on the strength parameters of the soil-additive mix. It was observed that the LLWA contains cementitious characteristics of lime and silica combined and can substantially reduce the plasticity and swell-shrink behavior of the soil and improve its strength and bearing characteristics. The UCS and CBR values have also shown multifold increase post curing with UCS and soaked CBR escalating by 278% and 387% respectively. The test results are further explained through the microstructure study which confirms the mineralogical transformation and cementation of soil particles. A one-dimensional rainfall-simulated leachate study has been carried out over a pavement model at the end to access the possible impact of ash treatment on the water table.