Engineering Properties of Industrial By-Products-Based Controlled Low-Strength Material

Controlled low-strength material (CLSM) also known by names such as flowable fill or controlled density fill is self-compacted in nature and used in civil engineering works such as backfills, void fills, conduit bedding and many more. These materials have strength lesser than 8.3 MPa. Generally, it consists of Portland cement, fine aggregate, fly ash and water but several other materials such as foundry dust and quarry dust can also be used. In this study, the different engineering properties of CLSM with different mix proportion were evaluated. Mix proportion mainly consists of red mud having 70%, 60% and 50% by weight of total composition along with fly ash of 20%, 30% and 40%, respectively, and phosphogypsum of 10% was studied. Portland cement was used as the binder material in all the composition in the proportion of 10% and 7% of the above composition. For different mix proportions considering flow value as an important parameter firstly percentage of water required for desired flow value (0.15–0.3 m) was evaluated by the trial method and then at those water content along with above mixture, other important engineering properties of CLSM such as compressive strength, bleeding and durability were evaluated. Except for the property of reexcavatibility (strength lesser than 2.1 MPa) for some composition all the other properties of all the composition were within the permissible limit. Overall it can be stated that red mud can be effectively used as one of the materials in CLSM.