Chemical stabilization of expansive soil using liming leather waste ash

The expansive soils have presented various challenges for geotechnical and civil engineers due to their low bearing capacity and high swelling-shrinkage characteristics. This study examines liming leather waste as an expansive soil stabilizer in ash form which has very limited use elsewhere. The black cotton soil-ash mix was checked for consistency limits, compaction parameters, UCS, CBR, swell and swell pressure for different proportions of liming waste ash. It was observed that the plasticity index, swell and swell pressure of the soil show a substantial decrease upon addition of the waste ash whereas the UCS and CBR values show a marked increase with unsoaked and soaked CBR escalating by around 138% and 310% respectively. The addition of 6% to 8% liming waste ash produced most desirable soil properties. The test results are supported through XRD, SEM and EDX analysis which confirm the formation of cementitious silica gel in various forms.

Automated summary

The addition of liming waste ash to black cotton soil can significantly improve soil properties, reduce soil expansiveness and swell pressure, and increase unsoaked and soaked CBR values.