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The pertinence of recycled brick aggregate (RBA) in concrete structures largely depends on their bonding ability with the rebars. Considering the practical detailing of concrete structures where main rebars are usually confined by stirrups, this study conducted bending pullout tests on 12 beam specimens to study the influence of concrete confinement on the bond behavior of rebar in RBA concrete. The investigated variables include RBA%, rebar diameter (), embedment length ( ), and the ratio of concrete cover to rebar diameter (). Bond stress-slip relationships were acquired, analyzed, and average bond strengths were compared to the AS 3600, CEB-FIP codes, and existing MacGregor's model. The average bond strength of confined specimens was nearly double that of the unconfined specimens. A progressive increase in bond strength was noticed with the presence of RBA regardless of confinement. The confined specimens also exhibited higher deformability, ductility, and toughness values than those of the unconfined beams. At 15% RBA content, the maximum toughness value of the confined specimen was 3078.1 J, while the unconfined specimens reached a value of 278.1 J, only. Similarly, the ductility of the confined beam was found in a range of 1.21-1.60 whereas the value is only 1.04-1.10 for the unconfined cases. Moreover, the confined specimens exhibited a significant number of cracks during their failure, while the unconfined specimens experienced a split type brittle failure. Nevertheless, these findings may contribute to the further development of the bond behavior of rebar in RBA-based concrete structures and thus play a role in the sustainability of construction materials.
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http://dx.doi.org/10.1016/j.heliyon.2024.e39925 | DOI Listing |
Bioresour Technol
September 2025
State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China.
The pyrolysis of flue-cured tobacco stalks (TS) faces challenges such as low bio-oil value and utilization efficiency. Existing studies have overlooked the anatomical heterogeneity of tobacco stalks, thereby limiting the directional regulation of high-value components, such as nicotine and phenolic compounds. This study divides TS into the husk (TSH), xylem (TSX), and pith (TSP), and investigates their physicochemical properties, pyrolysis behavior (through TGA and fixed-bed pyrolysis experiments), and interactions.
View Article and Find Full Text PDFJ Colloid Interface Sci
September 2025
Key Laboratory of Urban Rail Transit Intelligent Operation and Maintenance Technology & Equipment of Zhejiang Province, College of Engineering, Zhejiang Normal University, Jinhua 321004, China. Electronic address:
Developing high-performance wearable flexible sensors that can adapt well to complex environments has become a hotspot. Herein, a polyvinyl alcohol based composite hydrogel sensor with high mechanical strength, desirable frost/swelling resistance, and highly sensitive sensing performance was proposed by a multi-component collaborative design strategy. Meanwhile, an intelligent gesture recognition system was established by combining machine learning algorithm.
View Article and Find Full Text PDFJ Colloid Interface Sci
September 2025
State Key Laboratory of Hydro Science and Engineering, and Department of Energy and Power Engineering, Tsinghua University, Beijing, 100084, China. Electronic address:
Hypothesis: On highly cleaned planar surfaces submerged in highly cleaned water, flat surface nanobubbles with an angle of attachment of ∼15 are observed - never on engineering surfaces submerged in plain water, though here unidentified cavitation nuclei are always present and cause low tensile strength.
Experiments: In the present study, surface nanobubbles are generated by standard experimental techniques on a polished steel surface, and we find that the shape and the angles of attachment of the bubbles are influenced by the local substrate topography. These observations align with the theory of non-adsorbed liquid zones, which explains a surface nanobubble as a bubble with a skin of contamination molecules, which bond along the bubble rim at a contact angle of ∼14.
Acc Chem Res
September 2025
Department of Chemistry, FRQNT Centre for Green Chemistry and Catalysis, McGill University, 801 Sherbrooke Street W, Montréal, Québec H3A 0B8, Canada.
ConspectusMolecular photochemistry, by harnessing the excited states of organic molecules, provides a platform fundamentally distinct from thermochemistry for generating reactive open-shell or spin-active species under mild conditions. Among its diverse applications, the resurgence of the Minisci-type reaction, a transformation historically reliant on thermally initiated radical conditions, has been fueled by modern photochemical strategies with improved efficiency and selectivity. Consequently, the photochemical Minisci-type reaction ranks among the most enabling methods for C()-H functionalizations of heteroarenes, which are of particular significance in medicinal chemistry for the rapid diversification of bioactive scaffolds.
View Article and Find Full Text PDFACS Macro Lett
September 2025
Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States.
Introducing dynamic covalent chemistries into polymer networks allows access to complex linear viscoelasticity, owing to the reversible nature of the dynamic bonds. While this macroscopic mechanical behavior is influenced by the dynamic exchange of these chemistries, connecting the microscopic dynamics to the bulk properties is hindered by the time scale conventional techniques can observe. Here, light scattering passive microrheology is applied to probe short-time dynamics of dynamic covalent networks that consist of telechelic benzalcyanoacetate (BCA) Michael acceptors and thiol-functionalized cross-linkers.
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