Assessment of Desiccation Cracks in Soil Fused with Biochar and Dolochar Using Digital Image Processing

The expansive soils exhibit high swelling and shrinkage characteristics, cracking, and stickiness which causes poor yielding of crops and high seepage of ground water through concerned soil. The cracking resistance of soil can be enhanced to maximize the yield and control seepage. In the present study, industrial waste biochar and dolochar was added with locally collected soil to assess the effects of those sustainable materials on engineering properties of soil as well as on enhancing the cracking resistance. Atterberg limits, free swelling index, compaction characteristics, and unconfined compressive strength tests on expansive soil were carried out at three different biochar contents (i.e., 2.5, 5, and 10%) and three dolochar contents (i.e., 5, 10, and 20%) added with bentonite. The development and proliferation of fractures in a desiccated soil specimen were captured using a digital image capturing device and processed. The results showed that at 5% biochar and 10% dolochar, optimum values were obtained. The crack intensity factor (ratio of the area of the cracks to the total specimen area), the average width, and the total area of cracks decreased with increasing biochar up to 5% and dolochar up to 10%, thereby increasing the relative integrity of the specimen.