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American Society for Testing and Materials

The paper recognizes that the introduction of polymers and advanced polymer composites in the civil engineering world has been a comparatively rapid process vis-s-vis other civil engineering materials when they were first introduced. Aerospace and marine industries have been first to utilize advanced polymer compounds, but recently there has been a growing interest among civil/structural engineers in the importance of the unique mechanical and in-service properties of these materials together with their customized fabrication technologies. The paper outlines the development stages of this exciting material and provides a look into the future prospects for it.

The evolution of and the way forward for advanced polymer composites in the civil infrastructure

Heavy metals contamination has become a global environmental problem owing to anthropogenic sources. They are considered a stern threat to humans, aquatic life, and harmful pollutants to water resources due to their toxicity and carcinogenicity. Nanomaterials (NMs) have been used extensively from the available diversity of sorbents for heavy metals removal from wastewater. This review looks at the results of research undertaken using various NMs in the sequestration of Cr (VI). NMs have shown to be efficient and effective for the treatment of wastewater polluted by Cr (VI) owing to their unique properties like surface effect and quantum effect. Besides their large surface area, they also show exclusive characteristics like higher capacity, higher specificity, higher affinity, self-assembly, great reactivity, and catalytic-potential, making them superior adsorbing materials than traditional materials for Cr (VI) removal. The functionalization of these NMs was discovered to enhance their characteristics, hence improving the sorption capacity of NMs for Cr (VI) sorption. From previous studies reported, synthesized NMs had high sorption capacity for Cr (VI) and high retention of the sorbate metals. The Cr (VI) sorption onto various NMs or its functionalized materials were observed to depend on the pH, quantity of sorbent, contact time and temperature. The Langmuir isotherm and pseudo-second-order kinetic models best depicted the equilibrium data of the sorption processes. The determined sorption capacity of the various NMs for Cr (VI) sorption determined from the Langmuir model ranged from 3.197 to 666.67 mg/g for carbon nanomaterials, 8.67–1052.63 mg/g for metal and metals oxide NMs and 59.17–854.7 mg/g for polymers composite.

A review of hexavalent chromium removal from aqueous solutions by sorption technique using nanomaterials

Structural performance of FRP confined seawater concrete columns under chloride environment

Effect of shear span-to-depth ratio on shear strength components of RC beams

Characterization of the mechanical properties of eco-friendly concrete made with untreated sea sand and seawater based on statistical analysis

Experimental and theoretical investigation on the hybrid CFRP-ECC flexural strengthening of RC beams with corroded longitudinal reinforcement

An industrial applicable method to improve the properties of recycled aggregate concrete by incorporating nano-silica and micro-CaCO3

This paper presents an experimental study on shear behavior of full-scale rectangular reinforced concrete (RC) beams under shear-strengthening of carbon fiber-reinforced polymer (CFRP) U-strips. The test involved five RC beams with transverse reinforcement, including one control beam, one shear-strengthened by externally bonded (EB) CFRP U-strips only, and the remaining three strengthened in shear by a hybrid bonded (HB) CFRP system under different normal pressures applied on the CFRP U-strips. The transverse reinforcing steel bars and CFRP U-strips were extensively instrumented with strain gauges, which enabled the accurate quantitative assessment of shear strength contributions from CFRP (Vf), stirrups (Vs) and concrete (Vc) during the whole loading process of a shear test. Further, by comparing Vs and Vc for beams with and without CFRP strengthening, the interactions can be evaluated and clarified. In addition, key features of shear behaviors, e.g. failure mode, load-deflection curves, shear capacity and ductility, shear crack angle, and strain development and distribution of stirrups as well as CFRP strips, are presented, compared and analyzed.

Biao Hu

Papers

Characterization of the mechanical properties of eco-friendly concrete made with untreated sea sand and seawater based on statistical analysis

Effect of shear span-to-depth ratio on shear strength components of RC beams

Experimental and theoretical investigation on the hybrid CFRP-ECC flexural strengthening of RC beams with corroded longitudinal reinforcement

An industrial applicable method to improve the properties of recycled aggregate concrete by incorporating nano-silica and micro-CaCO3

Shear strength components of adjustable hybrid bonded CFRP shear-strengthened RC beams