(332f) Lime Sludge: An Emerging Alternate Construction Building Material for the Partial Replacement of Fine Aggregate

Lime sludge genrated in chemical recovery section of a paper mill is recoverd through brurning lime kiln. Lime sludge generated from agro based paper mill poses problem in lime kiln due to high amount of silica.  There is need to seek its utilisation in various other industrial applications as secondary raw materials. This present study is focused on the utlisation of lime sludge in making concrete blocks. The experimental investigations are concerned with strength of concrete and optimum percentage of the partial replacement by replacing fine aggregate via 25 %, 30 %, 35%, 40 % and 50% of lime sludge. The mixture of concrete of lime sludge, fine aggregate, coarse aggregate, ordinary portland cement, polymeric binders, and water were prepared by using standard consistency method as per IS: 10262-2009. The dimensions of cubes were 100mm X 100mm X 100mm. Different concrete mixes by using lime sludge, fine aggregate, coarse aggregate, and cement in the varying proportions were prepared with water to binder w/(c + LS) ratio of 0.48 to 0.80 for target strength of 37 (N/mm²). The compressive strength of the cubes of concrete is reduced with the replacement of lime sludge of pulp and paper mill over the control cement cube concrete. However with the use of plasticisers the strength of concrete bloacks can be enhanced to a stisfactory level with the lime sludge replacment upto 30%. The effect of compressive strength at 7 days and 28 days has been discussed here.