| 1. |
- Eltantawi, I., et al.
(författare)
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Bond performance of tensile lap-spliced basalt-FRP reinforcement in high-strength concrete beams
- 2022
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Ingår i: Composite structures. - : Elsevier BV. - 0263-8223 .- 1879-1085. ; 281
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Tidskriftsartikel (refereegranskat)abstract
- This paper investigates the bond between high-strength concrete (HSC) and tensile lap-spliced basalt fiber-reinforced polymer (BFRP) bars. Ten large-scale BFRP-reinforced concrete beams (300 × 450 × 3900 mm) were fabricated and tested under four-point loading until failure. The parameters investigated included the BFRP bar diameter (10, 12, and 16 mm), the splice length (400–1200 mm range), and the bar surface texture (sand-coated (SC) and helically wrapped (HW)). Test results demonstrated that the flexural capacity of the beams reinforced with SC-BFRP bars was almost similar to that of beams reinforced with HW-BFRP bars. However, SC-BFRP bars showed a slightly higher bond with concrete compared to that of helically wrapped counterparts. The bond strength of spliced BFRP bars was inversely related to the splice length. Also, BFRP bars with larger diameter bars require longer splice lengths to reach their maximum capacity. Finally, the experimentally estimated critical splice lengths were compared to those calculated by existing models and code-based equations. Both ACI 440.1R-15 and CSA S806-12 provisions were conservative in predicting splice length for BFRP bars. However, the CSA-S6-14 design code was more accurate in estimating the splice length for BFRP with bigger diameters. Though, it was not conservative with smaller diameters.
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| 2. |
- Younis, Adel, et al.
(författare)
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Comparative Carbon-Footprint Analysis of Residential Buildings with Different Structural Materials
- 2022
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Ingår i: State-of-the-art Materials and Techniques in Structural Engineering and Construction. - : ISEC Press.
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Konferensbidrag (refereegranskat)abstract
- An important step towards achieving sustainability goals in the construction sector is taken by developing solutions that adopt ‘greener’ structural materials for buildings. This paper establishes a comparison among four existing residential buildings in Sweden, that utilize different structural solutions, in terms of their global warming potential (GWP). The structural solutions compared are prefabricated reinforced concrete (RC), light timber frame, cross-laminated timber (CLT) panels, and CLT modular construction. For each building, a life cycle assessment (LCA) was performed to estimate the greenhouse gas (GHG) emissions attributable to material production. In general, the results of this study revealed climate benefits associated with timber-based construction, with approximately 50% savings on average in the GHG emissions per unit floor area of the buildings as compared to prefabricated RC construction. Finally, this effort demonstrates the significance of the structural material choice on the overall carbon footprint of a building, especially at the production stage.
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| 3. |
- Younis, Adel, et al.
(författare)
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Cross-laminated timber for building construction : A life-cycle-assessment overview
- 2022
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Ingår i: Journal of Building Engineering. - : Elsevier. - 2352-7102. ; 52
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Forskningsöversikt (refereegranskat)abstract
- The building industry is a large contributor to greenhouse gas (GHG) emissions and a vast consumer of natural resources. It is estimated that, in the next 40 years, around 415 Gt of CO2 will be released as a result of global construction activities. Therefore, improvements in construction technologies are essential to reduce GHG emissions and thereby attain national and international goals to mitigate climate change. Cross-laminated timber (CLT) has emerged as an innovative alternative material to steel/concrete in building construction, given its relatively low carbon footprint, not to mention its high strength-to-weight ratio, simple installation, and aesthetic features. CLT is a structural composite panel product developed in the early 1990s, and the contemporary generation of CLT buildings are yet to reach the end of their service life. Accordingly, there has been growing interest to understand and optimize the performance of CLT in building construction. In view of that, this paper presents an overview on the feasibility of using CLT in buildings from a life-cycle assessment (LCA) standpoint. The authors performed a brief review on LCA studies conducted in the past decade pertaining to the carbon footprint of CLT buildings. On average, the findings of these studies revealed about 40% reduction in carbon footprint when using CLT in lieu of conventional construction materials (steel/concrete) for multi-story buildings. Furthermore, the paper explores the challenges associated with conducting LCA on CLT buildings, identifies the gaps in knowledge, and outlines directions for future research.
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| 4. |
- Younis, Adel, 1990-, et al.
(författare)
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Shear strength of recycled-aggregate concrete beams with glass-FRP stirrups
- 2022
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Ingår i: Composites Part C: Open Access. - : Elsevier BV. - 2666-6820. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The combined use of recycled concrete aggregate (RCA) and glass fiber reinforced polymer (GFRP) reinforcement in reinforced concrete (RC) structures is deemed plausible to achieve sustainable construction. This paper aims to examine the effect of such a combination (RCA + GFRP reinforcement) on the shear behavior of RC beams. Six medium-scale RC beams (150 × 260 × 2200 mm) critical in shear were tested under three-point loading until failure. The test variables were the aggregate type (natural/recycled) and the shear reinforcement (steel/GFRP/none). The failure modes, cracking patterns, load-carrying capacities, deformational and strain characteristics were analyzed and compared among the tested specimens. It was found that using 100% RCA in the concrete mix reduced the shear strength of RC beams (by 12% on average). Minor effects were observed on the shear strength of the beam specimens (∼2%) with altering the transverse reinforcement (GFRP versus steel). Theoretical load-carrying capacities of the tested beams were obtained as per contemporary design guides and compared with the experimental results.
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