Search

This study characterizes the transmittance behavior of structural light-transmitting concrete under natural sunlight. The experimentation involves the use of a novel test setup and a detailed analysis considering the variation and dependence on time of day, month of the year and seasonal variations. The test set consisted of 28 variations of fiber configurations, with two different diameters, spacing and bundling techniques used to increase the area of fibers while maintaining spacing to aid the placing of concrete without compromising on transmittance. The study provides a real-time observational understanding of the behavior of light-transmitting concrete, a result usually obtained by modelling and simulation. The statistical analysis helps in understanding the impact of various variables as well as their interrelationships, which can help in design optimization. Based on the behavior as well as the stipulations of standards, the applicability of the material to various structural applications has been identified. [ABSTRACT FROM AUTHOR]

The durability of the self compacting concrete is one of the prominent areas of concern in recent years since it has become prevalent due to its ease of handling in the construction industries. However, there is a lack of detailed durability study of M-sand self compacting concrete with polypropylene fibres in the literature. In this paper, self compacting concrete made by Portland pozzolana cement with natural sand and M-sand, different percentages of volume fraction (0%, 0.1%, 0.15% and 0.2%) polypropylene fibres with M-sand is thoroughly investigated for fresh properties, hardened properties, drying shrinkage, water absorption, permeability, acid resistance and corrosion crack initiation time. Further, SEM analysis was carried out to know the effect of polypropylene fibre on the concrete microstructure. The results confirmed that the use of M-sand has improved the fresh, hardened and durability properties of the self compacted concrete than natural sand. Also, it is observed that the addition of polypropylene fibres has reduced the fresh properties of self compacted concrete. However, M-sand with 0.15% polypropylene fibres has slightly improved the strength of self compacting concrete, compression strength by 6.97%, split tensile by 8.68% and flexure strength by 3%. Further, it has reduced the drying shrinkage by 40%, water absorption by 30%, water penetration by 33.33%, and increased the chemical resistance, surface crack initiation period than the natural sand self compacting concrete. Finally, this study concludes that M-sand with 0.15% polypropylene fibres improves the durability of self compacting concrete by reducing effect from aggressive environments and in turn contributes to increased corrosion resistance of reinforcements embedded in concrete. Thus, the study supports the use of self compacting concrete with M-sand and optimum amount of polypropylene fibres to achieve required sustainability in terms of strength and durability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Early hydration is accelerated due to the addition of nano-silica. • The pore structure of the OPC-GGBS binder is refined by the addition of nano-silica. • EAF aggregate-based High strength HPC is achieved using nano-silica. • The combination of EAF aggregate and nano-silica in HPC showed improved characteristics. The present study investigates nano-silica (NS) in ternary binder composite and the influence of the same on Electrical Arc Furnace (EAF) slag coarse aggregate-based various high-performance concrete (HPC) mixes. Processed Quarry Dust (PQD) was used as fine aggregate throughout the investigation to limit the consumption of natural river sand and make HPC more sustainable. Control HPC was designed using the Ordinary Portland Cement (OPC)- Ground Granulated Blast Furnace Slag (GGBS) binary binder and various replacement levels of natural crushed granite rock aggregate by EAF coarse aggregate. Additionally, the binary binder composite was added with colloidal nano-silica to achieve high strength HPC. A microstructure study was carried out on paste samples of OPC, OPC with GGBS, and OPC, GGBS with the inclusion of nano-silica. FESEM, EDX, XRD, FTIR, and TGA results showed that the addition of nano-silica has significantly enriched the microstructure characteristics of the binder system. The slump flow of HPC mixes decreased drastically with the inclusion of nano-silica and EAF aggregate. Mechanical properties viz., compressive strength, split tensile strength, flexural strength, and modulus of elasticity of HPC mixes containing EAF and nano-silica have exhibited superior results due to the synergetic effect of nano-silica as well as the more robust physical characteristics of EAF aggregate compared to natural crushed granite rock aggregate. The UPV values and water absorption tests have shown that nano-silica positively affects the binder composite system. [ABSTRACT FROM AUTHOR]