Effect of various powder content on the properties of sustainable self-compacting concrete

This research goal is to evaluate the characteristics of glass powder (GP), quartz powder (QP), and limestone powder (LP) as Supplementary Cementitious Materials (SCMs) to replace cement content in terms of fresh and hardened properties of Self-Compacting Concrete (SCC) for sustainable building construction. Moreover, the obtained results were modeled using a soft computing approach. This investigation created ten mixtures incorporating varying percentages of GP, QP, and LP by replacing cement at about 0 %, 10 %, 20 %, and 30 %, respectively. The slump flow and J-ring tests were done to observe how SCMs affected the properties in fresh condition. In addition, the mechanical properties and pore structure configuration of the specimens were investigated. It was observed that GP and LP positively affected the fresh properties, increasing the mixes flowability by up to 8 %. Moreover, 20 % GP was able to enhance the compressive strength by 7 % by improving the pore structure of the cement matrix, which was confirmed by the mercury intrusion porosimetry analysis. Finally, the built machine learning models indicated good accord with test outcomes for Artificial Neural Network (R2 = 0.95) and could be applied to calculate the compressive strength of concrete containing GP, QP and LP for construction housing sector

Eco-friendly and cost-effective self-compacting concrete using waste banana leaf ash

The requirements of higher cement content and numerous admixtures in self-compacting concrete (SCC) yield a comparatively high production due to the high cement consumption that limits its use in everyday construction. As a result, it is prudent to consider alternatives for decreasing the environmental effects while producing a cost-effective SCC. Therefore, this study aims to investigate the fresh mechanical, durability, and microstructural characteristics as well as the environmental impacts of self-compacting concrete (SCC) incorporating waste banana leaf ash (BLA) to determine the optimum percentage of BLA. Concrete mixtures with 10%, 20%, and 30% OPC substitutions were investigated. Test findings revealed that all the fresh mixes performed within the EFNARC (2002) recommended limit. Despite the fact that increasing concentrations of BLA reduced the mechanical properties, concentrations of up to 20% BLA demonstrated strength comparable to the control mix. Furthermore, chloride ion penetration increased to 4%, with 20% BLA replacement falling into the moderate ion permeability zone. Finally, a relatively lower CO2-eq (maximum 29.13% reduction) per MPa indicates a significant positive impact due to the reduced Global Warming Potential (GWP)

On the utilization of rice husk ash in high-performance fiber reinforced concrete (HPFRC) to reduce silica fume content

The HPFRC refers to a category of fiber-reinforced cement-based materials that have the remarkable capability to flex and strengthen prior to shattering. At present, research is being conducted with the intention of producing a worldwide guideline for the development of structures using HPFRC. However, due to its high initial price and constrained availability, its implementation is challenging, particularly in developing countries. In this study, the effects of fly ash (FA) and rice husk ash (RHA) were examined, with 10%, 20%, and 30% of the cement replaced with FA. Furthermore, the mix providing maximum compressive strength was then taken to replace the silica fume content at 10, 20, 30, and 40% by RHA, steel fiber was also added to optimize the compressive and flexural ductility performance of the specimens. An extensive evaluation of fresh, mechanical, microstructural, and durability of HPFRCs were carried out. In addition, the eco-mechanical properties of fiber-reinforced concrete are studied by taking into account the post-peak behavior of the manufactured specimens and associated CO2 emissions. Test results show that the maximum improvement in compressive, tensile, and flexural strengths was 6.49%, 12.85%, and 5.27%, respectively, at 10% RHA replacement. In addition, as the concentration of RHA increased, the flexural bending toughness increased between 7.4% and 9.2%, with good agreement between the analytical models and the experimental results of the uniaxial compressive stress–strain. Moreover, the gradual increase in RHA concentration improved the durability of the HPFRCs, as evidenced by a maximum reduction in sorptivity coefficient of up to 48 percent for 30% RHA replacement. Finally, the investigation shows how the eco-mechanical index (EMI) can be used to evaluate material design options for HPFRCs. Please note an (erratum/corrigendum) for this article is available via https://www.sciencedirect.com/science/article/pii/S095006182301613

Performance evaluation of high-performance self-compacting concrete with waste glass aggregate and metakaolin

High-Performance Self-Compacting Concrete (HPSCC) has attracted much attention in recent decades due to its remarkable ability to fill formworks with densely packed reinforcing bars while requiring minimal or no external compaction. Because of the negative environmental impacts of cement and natural aggregates in concrete production, a much more sustainable alternative to manufacturing HPSCC is required. Recycled glass waste is one of the most attractive waste materials that can be used to create sustainable concrete compounds, which is currently a major area of study among researchers. This study aims to develop information not only about the fresh, mechanical, and durability characteristics of HPSCC, evaluate the environmental impact and correlate the crushing strength using a non-destructive approach by utilizing waste glass aggregates at replacement percentages of 0%, 10%, 20%, 30%, and 40%. To improve the performance of the produced HPSCC, Metakaolin was also added. The results of the fresh concrete tests revealed that the substitution of an optimal level of waste glass with Metakaolin provides adequate implementation in flowability, passing ability, and viscosity behaviors. Even though there is a reduction in the mechanical performance with glass aggregates, Metakaolin significantly improved strength and ductility by up to 16.12% and 15.91%, respectively. Furthermore, in most cases, the use of glass aggregates with Metakaolin significantly alters the durability properties of concrete while minimizing the environmental impact as well as the overall project cost. Finally, the NDT assessment demonstrates that the analytical equation can efficiently predict the compressive strength and promising to use for field application

Integration of Rice Husk Ash as Supplementary Cementitious Material in the Production of Sustainable High-Strength Concrete

The incorporation of waste materials generated in many industries has been actively advocated for in the construction industry, since they have the capacity to lessen the pollution on dumpsites, mitigate environmental resource consumption, and establish a sustainable environment. This research has been conducted to determine the influence of different rice husk ash (RHA) concentrations on the fresh and mechanical properties of high-strength concrete. RHA was employed to partially replace the cement at 5%, 10%, 15%, and 20% by weight. Fresh properties, such as slump, compacting factor, density, and surface absorption, were determined. In contrast, its mechanical properties, such as compressive strength, splitting tensile strength and flexural strength, were assessed after 7, 28, and 60 days. In addition, the microstructural evaluation, initial surface absorption test, = environmental impact, and cost–benefit analysis were evaluated. The results show that the incorporation of RHA reduces the workability of fresh mixes, while enhancing their compressive, splitting, and flexural strength up to 7.16%, 7.03%, and 3.82%, respectively. Moreover, incorporating 10% of RHA provides the highest compressive strength, splitting tensile, and flexural strength, with an improved initial surface absorption and microstructural evaluation and greater eco-strength efficiencies. Finally, a relatively lower CO2-eq (equivalent to kg CO2) per MPa for RHA concrete indicates the significant positive impact due to the reduced Global Warming Potential (GWP). Thus, the current findings demonstrated that RHA can be used in the concrete industry as a possible revenue source for developing sustainable concretes with high performance