Model tests on geosynthetic-encased construction concrete debris column in fly ash fill

Providing geosynthetic-encased stone columns is a commonly adopted technique to improve the load-carrying capacity and reduce settlements in weak fills. Addressing the geo-environmental aspect, two different waste materials, i.e., fly ash and concrete debris, have been used for the sustainable environmental management. This paper presents a series of model tests results carried on single unencased and geosynthetic-encased construction concrete debris (CCD) column installed in fly ash fill under short-term loading. Footing size was taken as twice the column diameter for 25% area replacement ratio. Two sizes of columns, 50mm and 75mm diameter, have been used for both end-bearing and floating end conditions. The results were analyzed in terms of bearing capacity ratio and settlement ratio. Experimental model tests clearly show that circumferential geosynthetic encasement greatly influences the ultimate load-carrying capacity of CCD column and reduces settlement of treated fly ash fill bed.