Mohammad Nadeem Akhtar
Department of Civil Engineering, Fahad Bin Sultan University, Tabuk,

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Influence of Natural Zeolite and Mineral additive on Bacterial Self-healing Concrete: A Review J. N. Akhtar; Rizwan Ahmad Khan; Rehan Ahmad Khan; Mohammad Nadeem Akhtar; Jamal K. Nejem
Civil Engineering Journal Vol 8, No 5 (2022): May
Publisher : Salehan Institute of Higher Education

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/CEJ-2022-08-05-015

Abstract

With time, the development of micro-cracks in concrete is a frequently reported problem in the structures due to the ingress of harmful substances, leading to the degradation of its quality and strength, which ultimately declines the construction. The present work is a review paper based on enhancing the self-healing property of concrete by inducing different bacteria alone or incorporating different mineral additives. It has been seen that various rehabilitated methodologies are in queue to surmount concrete’s weaknesses and to increase its strength and durability. The latest methodology includes using non-pathogenic microbes in concrete as Microbial induced Calcium Carbonate Precipitation (MICCP). The property of precipitating calcium carbonate (CaCO3) crystals by their metabolic activities helps repair the cracks in harsh conditions and improve their strength. Ureolytic bacteria like Bacillus pasteurii/Sporosarcina pasteurii, Bacillus subtilis, Bacillus megaterium, etc., have a specific property by which they can excite urea when integrated with a calcium source and help in sealing the cracks by CaCO3 precipitation. Different studies have observed that specimens having a bacterial concentration of 105-107 cells/ml with Natural Zeolite (NZ) replacement (10%) represents better interaction of the microstructure of concrete because of the formation of calcium silicate hydrate (CSH) gel. Further, the reduction in CH bond with reduced pore space has also been observed. NZ alone enhances micro-structural property, but it shows CaCo3 precipitation and more densification of microstructure under bacterial combination. XRD also confirms an increase in the calcite composition when the bacterial concentration of 105-107 cells/ml is used. The overall properties of standard and high-strength bacterial concrete (105-107 cells/ml) with 10% Natural Zeolite replacement can provide a better option for the future of sustained and strong concrete. Doi: 10.28991/CEJ-2022-08-05-015 Full Text: PDF
Enhancing Sustainability and Economics of Concrete Production through Silica Fume: A Systematic Review Ayedh Mohammad Alhajiri; Mohammad Nadeem Akhtar
Civil Engineering Journal Vol 9, No 10 (2023): October
Publisher : Salehan Institute of Higher Education

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/CEJ-2023-09-10-017

Abstract

This review article addresses the problems associated with the carbon footprint of the cement industry. The PRISMA framework methodology was for data extraction from published studies. In-depth research has been done in the literature on using silica fume as a cement replacement in concrete production, considering environmental, engineering, and economic (EEE) factors. The strength, durability, and economic parameters results revealed a positive variation of up to 5–20% substitution of silica fume. However, most past studies reported the threshold at a 10% replacement ratio. A novel benefit-cost ratio analysis was also done in this review study. The benefit-cost ratio analysis reveals the economically beneficial effects that can be achieved in sustainable silica fume-based concrete with a (5–20%) silica fume combination. The benefit-cost ratio showed positive effects, up to 20% cement replacement with silica fume. Hence, the higher cement replacement with silica fume is also beneficial in terms of the benefit-cost ratio. Further research has been proposed based on the findings of this review study. Doi: 10.28991/CEJ-2023-09-10-017 Full Text: PDF
Evaluating Recycled PET as an Alternative Material for the Construction Sector Towards Sustainability Omar Albatayneh; Mohammad Nadeem Akhtar
Civil Engineering Journal Vol 10, No 4 (2024): April
Publisher : Salehan Institute of Higher Education

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/CEJ-2024-010-04-020

Abstract

Addressing the environmental threat of Polyethylene Terephthalate (PET) waste is critical for sustainable development. Despite PET's prevalence in everyday products, its improper disposal endangers environmental health. This study targets a pivotal gap in current research. PET waste's potential as a sustainable building material will be thoroughly evaluated, focusing on whether recycling PET waste is feasible. In the construction industry, it can be a substitute for natural sand and an additive in cement. This study contributes to a dual-purpose solution: mitigating environmental pollution and innovating in construction material science. The systematic literature review (SLR) delves into existing studies, focusing on PET's impact on concrete properties when substituting natural sand at ratios of 5% to 20% and as a cement additive at 0.5% to 2% by weight. The findings revealed that up to a 10% PET replacement enhances compressive strength, highlighting a sustainable pathway for construction practices. However, replacements above 10% show a reduction in strength, indicating an optimal substitution threshold. Moreover, incorporating PET additives at 1% by cement weight optimizes flexural strength, underscoring the material's viability in enhancing structural integrity. This study sheds light on PET waste's application in reducing environmental impact and proposes a viable, eco-friendly alternative for construction materials. The recommendation for further research underscores the necessity to refine PET's application in construction, aiming to bridge the knowledge gap and encourage sustainable future innovations. Doi: 10.28991/CEJ-2024-010-04-020 Full Text: PDF
Durability Assessment of Sustainable Mortar by Incorporating the Combination of Solid Wastes: An Experimental Study Mohammad Nadeem Akhtar; Dima A. Husein Malkawi; Khaldoon A. Bani-Hani; Abdallah I. Husein Malkawi
Civil Engineering Journal Vol 9, No 11 (2023): November
Publisher : Salehan Institute of Higher Education

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/CEJ-2023-09-11-09

Abstract

The excessive mining of high-quality river sand for cement sand mortar resulted in environmental impacts and ecological imbalances. The present study aims to produce sustainable mortar by combining solid waste such as desert sand, stone dust, and crumb rubber to fully replace river sand. In addition, replacing cement with silica fume helps reduce the environmental carbon footprint. The present research prepared three types of mortar mixes: natural dune sand mortar (M1), natural dune sand stone dust crumb rubber mortar (M2), and natural dune sand stone dust crumb rubber silica fume mortar (M3). The developed mortar samples were examined at ambient and elevated temperatures of 100°C, 200°C, and 300°C for 120 minutes. Furthermore, 3 cycles of 12 hours each at freezing temperature (-10° ± 2°C) and crushed ice cooling (0° to -5°C) were also tested. Results of the study showed an increment in compressive strength values in M1, M2, and M3 mortar mixes (up to 200°C). Later, an abrupt drop in the compressive strength was noticed at 300°C in all mixes M1, M2, and M3, respectively. The mix M3 combinations resist heating impacts and perform significantly better than other mixes M1 and M2. Also, M3 combinations resist the cooling effect better than M1 and M2. It can be concluded that the mortar mix M3 with desert sand, stone dust, crumb rubber, and silica fume combination is considered the best mix for both heating and cooling resistance. Hence, the developed sustainable mortar M3 combination can be utilized in all adverse weather conditions. Doi: 10.28991/CEJ-2023-09-11-09 Full Text: PDF