Effects of carbonation modification on shear performance of recycled aggregate concrete beams: Test and mechanism analysis
The effective use of recycled aggregates (RAs) in construction significantly contributes to environmental preservation and the conservation of non-renewable natural resources. However, RAs typically exhibit inferior performance relative to natural aggregates (NAs). To improve the quality of RAs, car...
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Veröffentlicht in: | Engineering structures 2024-09, Vol.315, p.118385, Article 118385 |
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Sprache: | eng |
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Zusammenfassung: | The effective use of recycled aggregates (RAs) in construction significantly contributes to environmental preservation and the conservation of non-renewable natural resources. However, RAs typically exhibit inferior performance relative to natural aggregates (NAs). To improve the quality of RAs, carbonation modification has been introduced as an eco-friendly and practical method. This study explores the shear performance of concrete beams that incorporate various replacement ratios (30 %, 50 %, 70 %, and 100 %) of carbonated recycled aggregates (CRAs). The experiment employed Digital image correlation (DIC) system to evaluate the stress distribution on the concrete surface within the shear span section. The evaluation of shear performance was conducted through comprehensive analysis includes load-deflection curve, steel strain, the width of the primary diagonal crack, average principal tensile strain, orientation of principal directions, average shear strain, and shear deflection. A practical approach was adopted to separate the shear strength contributions of transverse steel (Vs) and concrete (Vc), based on transverse steel strains along the primary diagonal crack. Results indicate that carbonated recycled aggregate concrete (CRAC) beams demonstrate enhanced shear performance in comparison to recycled aggregate concrete beams. Shear strength significantly decreases with replacement rates exceeding 70 %. Furthermore, the experimental results were compared against shear strength with the design codes, and shear deflection with existing models.
•The ultimate shear strength of carbonated recycled aggregate concrete (CRAC) beams tends to decrease as the rate of carbonated recycled aggregate (CRA) replacement rises.•The shear contribution of concrete (Vc) in CRAC beams increases with CRA replacement rate, whereas the shear contribution of transverse steel (Vs) in CRAC beams decreases.•The principal compressive strain angle of CRAC beams is correlated with the inclination of the primary diagonal cracks.•The proportion of shear deformation in the total deformation increases with CRA replacement rate of CRAC beams.•By comparing existing shear deflection models with experimental results, JCSE model provides a more accurate prediction of shear deflection for CRAC beams. |
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ISSN: | 0141-0296 1873-7323 |
DOI: | 10.1016/j.engstruct.2024.118385 |