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 CO
-eq (equivalent to kg CO
) 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.
This paper studies the fresh and mechanical properties of high-strength concrete (HSC) by incorporating recycled concrete aggregates (RCA) of varying sizes and concentrations. The recycled aggregate ...concrete (RAC) was prepared by partially replacing RCA with natural coarse aggregate (NCA) at 0%, 15%, 30%, and 45%, with aggregate sizes ranging from 5 to 12 and 12–20-mm. Fresh concrete properties, such as slump, Kelly ball, compacting factor, K-slump, and fresh density, were tested to determine the influence of RCA size and concentration. In addition, the mechanical properties were studied through the execution of compressive, split-tensile, and stress-strain tests. The test results revealed that increasing the RCA concentration declines the fresh and hardened properties of HSC. In the fresh concrete experimentation, the 12–20 mm aggregate size RAC mixes exhibited greater workability than the 5–12 mm aggregate mixes. On the contrary, 5–12 mm aggregate mixes RAC had higher compressive and split-tensile strength and a higher modulus of elasticity than 12–20 mm aggregate mixes concrete. When it comes to sustainability, the study found that the smaller size range of RAC produces inferior embodied CO2(eCO2) and provides a cost-effective and sustainable solution for the construction industry.
The use of recycled aggregates (RA) in the concrete industry has become increasingly popular due to the reduction in natural aggregate (NA) consumption and the ability to reuse demolition waste. This ...research focuses on analyzing the performance of recycled aggregate concrete (RAC) cured with sodium sulfate (Na2SO4). Five different mixtures were created, varying from 0% RA without supplementary cementitious material (SCM), to 0%, 15%, 30%, and 45% substitution of NA with RA and SCM. The slump test was performed on all fresh RAC mixtures, which showed a decrease in slump with an increase in RA content. Both 5% Na2SO4 solution curing at 91 days and standard curing at 7, 28, and 91 days resulted in a reduction in compressive strength and ultrasonic pulse velocity (UPV) as the proportion of RA increased. Compared to standard curing, the compressive strength of specimens cured with 5% Na2SO4 solution at 91 days showed a decrease of approximately 5-7%. The UPV of SCM-based mixes showed 14-28% improvement with respect to normal aggregate concrete (NAC) in normal water curing. Furthermore, the SCM-included specimens have produced less deterioration in Na2SO4 immersion as SCM particles resist the severity of the dominant sulfate environment.
This paper presents and discusses the results of the study on physical and mechanical properties of Industrial Waste Modified Mortar (IWMM) in comparison to Unmodified Mortar (UM). Industrial wastes ...used as ternary cement replacement were Micro Silica (MS) and Finely Ground Waste Vase (FGWV). Porosity and compressive strength of cement based products are the crucial properties that reflect the durability. Results of this study showed incorporation of 15%MS and 20%FGWV as ternary binders reduced 32.8% porosity and increased 4.3% compressive strength of mortar.
In this study, aluminium dross waste generated from aluminium smelting industries was employed as adsorbent in removing of congo red dye in aqueous solution. The raw aluminium dross as adsorbent was ...characterized using Scanning Electron Microscope (SEM), Brunauer-Emmett-Teller (BET) for surface area and X-Ray Fluorescence (XRF) Spectroscopy. Adsorption experiments were carried out by batch system at different adsorbent mass, pH, and initial dye concentration. The results showed that the per cent removal of dye increased as adsorbent mass increased. It was found that 0.4 gram of adsorbent can remove approximately 100 % of dye at pH 9 for dye concentration 20 and 40 ppm. Therefore, it can be concluded that raw aluminium dross without undergone any treatment can be effectively used for the adsorption of congo red in textile wastewater related industries.
The characteristics of catalysts impregnated in coconut shell (CS) and palm kernel shell (PKS) activated carbon were determined as potential precursors of catalysts used in a flue gas denitrification ...system at low temperature. In this study, Manganese (Mn) and Copper (Cu) with metal loading of 8% were impregnated in the activated carbon (AC) before undergoing low temperature calcination process. The morphological properties of samples was analysed using Scanning Electron Microscopy (SEM) and Brunauer, Emmett and Teller (BET) was used to determine the surface area and pore size of samples. The exhaust gas from a diesel engine at a constant flow rate of 4L/min was passed through in a fixed-bed catalytic reactor containing the catalyst, and the concentration of NOx was measured for temperatures ranging from 150°C to 250°C. It was found that the CS catalysts (CS-Mn and CS-Cu) and PKS catalysts (PKS-Mn and PKS-Cu) have the potential to reduce NOx concentration, and results showed that the metal loading of 8% resulted NOx reduction ranging from ~48% to 64%.
A growing interest of sugarcane bagasse fibre composite has been observed in recent years due to its attractiveness properties such as low specific weight, renewable source and producible with low ...investment at low cost. However, these materials have a low interfacial adhesion between fibre and matrix which lead to reduction in certain mechanical properties of the composite. To overcome this problem, studies show that certain chemical treatments on the surface of the fibres are some alternatives that significantly increase the adhesion reinforcement/matrix, in some cases improving its mechanical properties. The objective of this study was to evaluate the effect of different type of chemical treatment which are alkali and acid treatment on sugarcane bagasse fibre surface morphology. Seeking to improve the adhesion fibre matrix, the fibre has been treated with 5% of NaOH and 5% of HCL solution with added of bagasse fibre used in the range of 0% to 3% of cement weight respectively. Through SEM investigation, it is confirmed that chemical treatment helps to remove hemicelluloses from raw bagasse fiber as well as improved fibre matrix adhesion.
Cement as an essential element for cement-based products contributed to negative environmental issues due to its high energy consumption and carbon dioxide emission during its production. These ...issues create the need to find alternative materials as partial cement replacement where studies on the potential of utilizing silica based materials as partial cement replacement come into picture. This review highlights the effectiveness of microstructural characterization techniques that have been used in the studies that focus on characterization of calcium hydroxide (CH) and calcium silicate hydrate (C-S-H) formation during hydration process of cement-based product incorporating nano reactive silica based materials as partial cement replacement. Understanding the effect of these materials as cement replacement in cement based product focusing on the microstructural development will lead to a higher confidence in the use of industrial waste as a new non-conventional material in construction industry that can catalyse rapid and innovative advances in green technology.
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