Pozzolanic Rendering of Lime Sludge and Sandstone Reject Blend Sandeep P. Tembhurkar, Akshaykumar Raut, and Mangesh V. Madurwar Abstract The author has investigated the pozzolanic property of blended industrial rejects collected in sludge form from the textile industry and sandstone quarry. The pozzolanic potential of a blend of rejects was examined at 10, 20, 25, 30 and 35% replacing the primary binder, i.e. cement. The percentage replacement of each material was examined after mechanical treatment, i.e. grinding for 30 min dura- tion. Percentage replacement was carried out based on quantitative presence of SiO 2 , Al 2 O 3 and Fe 2 O 3 in industrial rejects to meet the requirement of IS 3812: (Part 1) 2013. The Pozzolana Activity Index, Chapelle Activity, and Electrical Conductivity tests were used to verify the pozzolanic ability of the blend. The Lime Sludge Reject (LSR) and Sandstone Sludge Reject (SSR) were characterized physically, chemically and mineralogically. The Ordinary Portland Cement (OPC) control mix will be used to compare the performance of blended concrete. The 28 days characteristic compressive strength (CCS) and durability properties were investigated. The identified industrial reject blend shows the improved poz- zolanic ef ficiency when analysed statistically for optimum replacement of cement to make the cement industry more sustainable. Keywords Pozzolanicity Á Supplementary cementitious material Á Industry rejects Á Lime sludge Á Sandstone sludge 1 Introduction The solid wastes are being generated all around the world from the agriculture, industries and mines. Asia alone generates 4.4 billion tons of solid wastes in a year [1]. In India, it was 960 million tons annually noted in the last decades [2]. The generated material has been used in the landfilling and remaining material has been dumped on the open land. The dumped waste gets decomposed by environmental S. P. Tembhurkar Á A. Raut Á M. V. Madurwar (&) Department of Civil Engineering, Visvesvaraya National Institute of Technology, Nagpur, Maharashtra, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Laishram and A. Tawalare (eds.), Recent Advancements in Civil Engineering, Lecture Notes in Civil Engineering 172, https://doi.org/10.1007/978-981-16-4396-5_26 283