| 1. |
- Chen, Gongmei, et al.
(författare)
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Machine learning-based evaluation of parameters of high-strength concrete and raw material interaction at elevated temperatures
- 2023
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Ingår i: Frontiers in Materials. - : Frontiers. - 2296-8016. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- High-strength concrete (HSC) is vulnerable to strength loss when exposed to high temperatures or fire, risking the structural integrity of buildings and critical infrastructures. Predicting the compressive strength of HSC under high temperature conditions is crucial for safety. Machine learning (ML) techniques have emerged as a powerful tool for predicting concrete properties. Accurate prediction of the compressive strength of HSC is important as HSC can experience strength losses of up to 80% after exposure to temperatures of 800°C–1000°C.This study evaluates the efficacy of ML techniques such as Extreme Gradient Boosting, Random Forest (RF), and Adaptive Boosting for predicting the compressive strength of HSC. The results of this study demonstrate that the RF model is the most efficient for predicting the compressive strength of HSC, exhibiting the R2 value of 0.98 and lower mean absolute error and root mean square error values than the other applied models. Furthermore, Shapley Additive Explanations analysis highlights temperature as the most significant factor influencing the compressive strength of HSC. This article provides valuable insights into the timely and effective determination of the compressive strength of HSC under high-temperature conditions, benefiting both the construction industry and academia. By leveraging ML techniques and considering the critical factors that influence the compressive strength of HSC, it is possible to optimize the design and construction process of HSC and enhance its resilience to high-temperature exposure.
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| 2. |
- Nadeem, Muhammad, et al.
(författare)
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Evaluation of mechanical properties of cored interlocking blocks – A step toward affordable masonry material
- 2023
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Ingår i: Results in Engineering (RINENG). - : Elsevier. - 2590-1230. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- This research study is about the evaluation of mechanical properties of locally prepared Cored 6” self-interlocking blocks. Currently, all the construction practices, whether brick masonry, block masonry, or reinforced concrete, are time consuming, relatively energy inefficient, not eco-friendly, and non-sustainable. Another issue in masonry construction is that the strength and behavior of bricks or blocks masonry depend upon the properties of the binding material (mortar) used in masonry wall joints. Considering these issues, Eco Blocks are newly introduced interlocking blocks with different sizes and shapes. Construction with interlocking blocks is faster, economical, and easier, as they do not require binding material. The aim of this study was to obtain the mechanical properties such as the compressive strength (individual block and prism), diagonal tensile strength, shear parameters, modulus of elasticity, shear modulus, and flexural strength of Cored 6′′ Eco Blocks through comprehensive experimental investigation. These showed encouraging results as compared with typical interlocking compressed earth blocks and also satisfied the threshold set forth by the international standards regulating earth construction. The compressive and flexural strengths of the blocks have been obtained as 6.03 MPa and 1.66 MPa, respectively. Based on the results outcomes, Cored 6” Eco Blocks can be utilized in load bearing walls.
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| 3. |
- Nagaraju, T. Vamsi, et al.
(författare)
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Development of sustainable high performance geopolymer concrete and mortar using agricultural biomass—A strength performance and sustainability analysis
- 2023
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Ingår i: Frontiers in Materials. - : Frontiers. - 2296-8016. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Geopolymer concrete is a sustainable substitute for traditional Portland cement concrete. In addition, rising carbon taxes on carbon emissions and energy intensive materials like cement and lime, impacts the cost of industrial by products due to their pozzolanic nature. This research evaluates the compressive strength and flexural strength of geopolymer concrete, and the compressive strength of geopolymer mortar. Geopolymer mortar data were used for the strength assessment employing an analytical approach, and geopolymer concrete data were utilized for the strength and sustainability performances. Using artificial neural networks (ANNs), multi-linear regression (MPR) analysis, and swarm-assisted linear regression, compressive strength models were created based on experimental datasets of geopolymer mortar mixes with variable precursors, alkali-activator percentages, Si/Al, and Na/Al ratios. The strength and sustainability performances of geopolymer concrete blends with various precursors were assessed by considering cost-efficiency, energy efficiency, and eco-efficiency. The work’s originality comes from enhancing sustainable high-performance concrete without overestimating or underestimating precursors. Extensive experimental work was done in the current study to determine the best mix of geopolymer concrete by varying silica fume, ground granulated blast furnace slag (GGBS), and rice husk ash (RHA). A scanning electron microscopic study was conducted to understand the geopolymer matrix’s microstructure further. A comprehensive discussion section is presented to explain the potential role of RHA. The replacement of conventional concrete in all its current uses may be made possible by this sustainable high-performance concrete utilizing RHA.
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| 4. |
- Vivek, S.S., et al.
(författare)
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Impact and Durability Properties of Alccofine-Based Hybrid Fibre-Reinforced Self-Compacting Concrete
- 2023
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Ingår i: Case Studies in Construction Materials. - : Elsevier. - 2214-5095. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- Many research works have already been made and are still in progress on metallic fibres, as their incorporation reduces the brittleness of the concrete and improves its resistance to the impact and crack propagation. But the use of such non-metallic fibres may induce corrosion which is a major problem to be addressed from the durability aspect. To overcome this problem, in the present research work, a non-metallic hybrid fibre combination was investigated with synthetic fibres like polypropylene and abaca fibres. Also, rather than using conventional cementitious materials such as silica fume, fly ash, and ground granulated blast furnace slag, a new generation of ultra-fine material namely alccofine was used as a partial replacement for the cement by 15%. Abaca fibre was utilised in a constant addition of 0.5% and blended with polypropylene fibre in a range varying from 0% to 2% with an increment of 0.5%. The fresh properties of self-compacting concrete (SCC) in mono and hybrid fibres combinations were assessed through slump flow, J-ring, and V-funnel tests. Water absorption and sorptivity tests were conducted to ensure the durability of the prepared mix. Further, impact tests were carried out on the prepared cylinder specimens to check the capability of the mix with the non-metallic hybrid combination. The main objective here was to check whether a high-strength durable SCC could be achieved using non-metallic fibres and natural fibres. From the obtained experimental results, it was observed that 15% alccofine as a partial substitute to the cement with the addition of 0.5% of abaca fibre and 2% of polypropylene fibre to SCC performed better than the control SCC.
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