Pond ash as a fine aggregate for controlled low-strength materials (CLSM): a study of its geotechnical and geoenvironmental aspects

Minimizing the utilization of natural resources and recycling industrial by-products on a large scale poses a severe challenge worldwide for sustainable development. Successful utilization of pond ash as a fine aggregate in controlled low-strength material (CLSM) enhances those possibilities. In this paper, laboratory tests were performed to determine the engineering properties of pond ash-based CLSM mixture and its feasibility, along with environmental assessment. The results showed that pond ash could be effectively used as fine aggregate in CLSM production with desired engineering properties. At maximum flowability, the w/c ratio reduces significantly with increased cement content. The strength properties of CLSM mix are exactly related to the percentage of cement content present in the mixture at constant flowability of 300 mm. Low cement content CLSM mixture was more compressible than higher cement content. The leaching concentration of heavy metals in the CLSM mix are within permissible limit according to USEPA threshold limit.