Strengthening of RC Structures by Using Engineered Cementitious Composites: A Review

This paper presents a review of the recent work assessing the performance of building structures strengthened with engineered cementitious composite (ECC). ECC characterizes tensile strain hardening and multiple cracking properties, as well as strong interfacial bonding performance with substrate concrete, which makes it a promising retrofitting material. A lot of researches have been conducted on reinforced concrete (RC) structures, including beams, columns, beam–column joints, and fire-damaged slabs, strengthened with ECC material, and an extensive collection of valuable conclusions were obtained. These strengthening systems usually combine ECC with FRP textiles or steel bars to form a composite strengthening layer. The review demonstrates that ECC strengthening can greatly improve the performance of RC structures.

Electrochemical Enantiomer Recognition Based on sp3-to-sp2 Converted Regenerative Graphene/Diamond Electrode

It is of great significance to distinguish enantiomers due to their different, even completely opposite biological, physiological and pharmacological activities compared to those with different stereochemistry. A sp3-to-sp2 converted highly stable and regenerative graphene/diamond electrode (G/D) was proposed as an enantiomer recognition platform after a simple β-cyclodextrin (β-CD) drop casting process. The proposed enantiomer recognition sensor has been successfully used for d and l-phenylalanine recognition. In addition, the G/D electrode can be simply regenerated by half-minute sonication due to the strong interfacial bonding between graphene and diamond. Therefore, the proposed G/D electrode showed significant potential as a reusable sensing platform for enantiomer recognition.

Metal Composites Behaviour Under Biaxial Stresses

For this study, different volume fraction (vol.%) of particulate alumina (Al2O3)reinforced aluminium alloy (Al 6061) with 5 vol.%, 15 vol.% and 25 vol.% are produced by powder metallurgy method. These samples were subjected to biaxial stresses in order to investigate the behaviour of the metal matrix composites (MMCs). Microstructure analysis on the individual sample before and after loading was performed under scanning electron microscopy. The small particles of 2 µm in size have exhibited strong interfacial bonding with the matrix. The particles of 5 µm in size have shown fractures and debonding interface. Large particles of above 20 µm in size have revealed severe fractures and particles pulled out. Behavior of the MMC was explained by relating the microstructures and displacement directions of the undeformed and deformed samples. Some understandings on the behaviour of the MMCs with different vol.% of Al2O3 due to biaxial stresses have been established.

Enhanced electromagnetic interference shielding behavior of Graphene Nanoplatelet/Ni/Wax nanocomposites

GNP/Ni/Wax nanocomposites fabricated by a molecular-level mixing process show enhanced shielding effectiveness due to homogeneously decorated Ni nanoparticles on GNP with strong interfacial bonding.

Graphite/Bio-Based Epoxy Composites: The Mechanical Properties Interface

Graphite reinforced bio-based epoxy composites with different particulate fractions of graphite were investigated for mechanical properties such as tensile strength, elastic modulus and elongation at break. The graphite content was varied from 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.% by weight percent in the composites. The results showed that the mechanical properties of the composites mainly depend on dispersion condition of the treated graphite filler, aggregate structure and strong interfacial bonding between treated graphite in the bio-based epoxy matrix. The composites showed improved tensile strength and elastic modulus with increase treated graphite weight loading. This also revealed the composites with increasing filler content was decreasing the elongation at break.