Feasibility of using bio-enzyme as an admixture in reactive powder concrete MA Raja, S Judes Sujatha Materials Research Express, 2023 Utilizing bio-based elements as cement additives has a significant impact on the production of extremely durable and sustainable concrete composites. In the present research work, the effect of a bio-enzyme (Terrazyme) on the strength, durability, and microstructure of RPC was researched at various proportions of Terrazyme (TZ) as binder replacement (0, 0.5, 1, 1.5, 2, and 2.5%). The migration of water and transport properties of concrete are accessed through measurement of the water absorption and gas permeability. Results show that the use of TZ in RPC slightly reduced the compressive strength, and the reduction was more significant at high replacement levels when subjected to water curing. A significant reduction in the permeability of RPC with a relatively low permeability coefficient is obtained even at higher dosages of TZ in autoclaved RPC specimens with greater mechanical strength. In addition, greater chloride penetration with the prolongation of ages is obtained. The inclusion of TZ can not only enhance the waterproofing and penetration resistance of RPC but also achieve economic and ecological benefits.
Effect of Elevated Temperature on the Properties of Self-Compacting Mortar Containing Nanomaterials and Zircon Sand Sahaya Ruben, M. Sophia, M. A. Raja, Chandran Masi Advances in Civil Engineering, 2022 The present research work tries to assess the performance of a self-compacting mortar containing zircon sand as a substitute for river aggregate in combination with nanoalumina and nanosilica as cement replacements. The fresh state results, as observed through the mini slump cone and mini V funnel, showed positive effects of zircon sand on workability attainment. The EFNARC limits of workability were even satisfied at high substitution levels of the nanoparticle due to the contribution of zircon sand. The mechanical properties, durability, and microstructure of the mortar were evaluated by conducting experiments at room temperature and then at 200°C, 400°C, 600°C, and 800°C. Results show that there was a significant improvement in the thermal stability of the RPC mixes due to the synergistic effect of nanomaterials and zircon sand addition. The addition of nanomaterials and zircon sand accelerated the microstructural buildup and durability at elevated temperatures. The findings thus suggest a novel and effective approach to using zircon sand as a potential alternative to quartz sand in RPC in combination with nanomaterials to produce temperature-resistant concrete structures.
