Mechanical and Microstructure Properties of Plain and Blended Cement Structural Lightweight Aggregate Concrete Using Sintered Fly Ash Aggregates

Abstract

Infrastructure and industry have grown dramatically as a result of globalization and urbanization. However, there are certain challenges, such as meeting infrastructural needs that require a large amount of extraction of natural aggregates and disposal of waste generated as a result of industrialization. Both of these challenges have an adverse impact on the environment. Deforestation, erosion, contamination of nearby streams, and increase in noise, dust, and emissions are all consequences of aggregate extraction. The industrial waste can contaminate groundwater, lakes, streams, rivers and coastal waterways and harm the land and neighboring water bodies. Hence these challenges must be addressed as a priority for environmental sustainability. The current study developed structural lightweight aggregate concrete (SLWAC) using sintered fly ash aggregate (SFA). The investigation was done with the use of different binders such as Portland Pozzolana Cement (PPC), Ordinary Portland Cement (OPC), and Micro Fibre Cement (MFC). The present study explores the suitable binder to produce SLWAC at different water-cement ratios of 0.4, a0.44, and 0.48. The performance evaluation of SLWAC was investigated by mechanical behavior like compressive strength, split tensile, flexural strength, and impact test. Microstructure analysis is also included in this study to validate the mechanical experiment results. SLWAC made from OPC shows more mechanical strength than PPC and MFC, due to faster hydration and early strength gain. SLWAC made from microfiber cement, has more strength as compared to PPC. This could be due to fibers in MFC, acting as a reinforcing agent, which reduces micro cracks. The microstructure of SLWAC shows that the wall effect does not exist in SLWAC compared to normal aggregate concrete. It has a uniform and continuous microstructure of hydration products and partially penetrates the SFA. It could be associated with the superior interfacial transition zone having a lower w/c ratio because of the higher absorption of SFA. The findings show that all developed SLWAC can be used in structural members like beams, columns, and slabs.