Browsing by Author "Mydin, Md Azree Othuman"

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    Bamboo stem ash as a sustainable cement replacement in lightweight foam mortar enhancing mechanical thermal and microstructural properties.
    (Scientific Reports, 2025) Mydin, Md Azree Othuman; Azman, Nurul Zahirah Noor; Awoyera, Paul O.; Özkılıç, Yasin Onuralp; Fadugba, Olaolu George; Abdullah, Mohd Mustafa Al Bakri; Omar, Roshartini; Datta, Shuvo Dip
    This study presents a novel approach to enhancing the properties of lightweight foam mortar (LFM) by utilizing bamboo stem ash (BSA) as a partial cement replacement. Unlike traditional supplemental cementitious materials (SCMs) like fly ash or silica fume, BSA provides a special blend of lightweight properties and a high silica concentration. Thus, the effect of BSA (in proportions of 0–25% and steps of 5%) on the mortars’ fresh, hardened, microscale properties, such as workability, density, strength, durability, and microstructural characteristics, was explored. At 15% BSA replacement, the compressive strength reached 8.25 MPa at 28 days, 7% higher than the control mix (7.7 MPa). The study identifies 15% BSA as the optimal replacement level, striking a balance between mechanical strength, durability, and thermal insulation. Beyond 15%, increased porosity begins to reduce strength, while thermal resistance continues to improve. Thus, a 10–15% replacement range is recommended for applications requiring structural integrity and insulation. The density of the foam mortar decreased from 1000 kg/m3 for the control mix to 960 kg/m3 at 20% BSA replacement, improving the material’s lightweight characteristics. Also, the porosity increased from 24.8% (control) to 30.2% (25% BSA), positively influencing thermal insulation properties. Thermal conductivity measurements indicated a reduction from 0.25 W/mK (control) to 0.18 W/mK at 25% BSA replacement, demonstrating improved thermal resistance. BSA incorporation improves the pore structure and fosters stronger interfacial bonding within the matrix, especially at 15% replacement, according to microstructural investigation using SEM. The water absorption rate increased slightly from 18.2% (control) to 21.6% (25% BSA), still within reasonable bounds for lightweight construction applications. As demonstrated by the mortars’ notable performance, BSA may effectively replace OPC in LFM, improving its mechanical, thermal, and environmental qualities. With the results, BSA has shown potential for developing eco-friendly building materials and aiding in reducing carbon emissions in the built environment. These results show that BSA can be a green and practical substitute for OPC in lightweight building applications, especially for prefabricated panels, insulation layers, and non-load-bearing walls. Its ability to enhance mechanical strength while reducing thermal conductivity makes it a promising material for energy-efficient and sustainable building solutions.
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    Sustainable innovation in foamed concrete using waste sanitary ware as fine aggregate for properties enhancement
    (Science Progress, 2025) Mydin, Md Azree Othuman; Sor, Nadhim Hamah; Al Bakri Abdullah, Mohd Mustafa; Isleem, Haytham F.; Dulaimi, Anmar; Awoyera, Paul O.; Fadugba, Olaolu George; Tawfik, Taher A.
    The solid waste generated by the waste sanitary ware (WSW) sector is of considerable magnitude on a global scale. Recycling ceramic waste is an essential practice that ensures its proper disposal. Therefore, the objective of this research endeavor was to investigate the effects of replacing sand with WSW on different characteristics of foamed concrete (FC), such as its thermal properties, transportability, freshness, and mechanical strengths. A range of replacement rates, ranging from 5% to 25%, was considered. The utilization of WSW replacements increases the initial and final setting times, along with the densities of the mixtures, according to the test results. Nevertheless, the slump of the fresh test decreases. Significant improvements were observed in the mechanical characteristics when the replacement ratio was established at 10%. Furthermore, the results of the scanning electron microscopy evaluation and pore distribution analysis indicated that the performance of FC containing up to 10% WSW was superior as a filler for pores. Also, the addition of WSW resulted in a decrease in sorptivity, porosity, and water absorption. Nevertheless, the thermal conductivity of FC was enhanced. Nevertheless, considering the comprehensive examination, the most optimal approach to manufacturing environmentally friendly FC may involve replacing 10% of WSW.