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In this article, CNTs have been used in concrete, and the resulting properties are evaluated. Also, the CNT-reinforced concrete was exposed to elevated temperature, and the corresponding change in mechanical performance was investigated. Mechanical properties were studied, such as compressive and flexural strengths, stress-strain response, elastic modulus, compressive toughness, mass loss, and deterioration caused by exposure to elevated temperatures. Concrete specimens were heated to 200, 400, 600, and 800 °C at a heating rate of 5 °C/min and then tested for residual properties. CNT-reinforced concrete showed a higher compressive strength, elastic modulus, flexural strength, and compressive toughness than the control specimens. 0.15-CNT reinforced samples showed an increase of nearly 33% in Compressive strength and 50% in flexural strength. From the visual inspection, CNT-reinforced specimens showed less cracking at higher temperatures. Moreover, the effect of plastering concrete with CNTs was studied, which depicted better strength retention on exposure to fire. At 600 °C, 0.3 P-CNT plaster samples retained up to 43% of compressive strength and 46% of flexural strength, whereas control samples only retained up to 29% and 34% of their original strengths, respectively. Thus, it can be concluded that CNTs utilization in concrete is efficient for improved concrete fire resistance. [ABSTRACT FROM AUTHOR]

Unreinforced masonry structures are vulnerable to seismic loading due to their brittle behavior, and must therefore be strengthened. This paper presents the seismic performance of brick masonry strengthened with steel and plastic meshes. For this purpose, twenty masonry wallets of (600 × 600 × 113 mm) were constructed, keeping the same materials and workmanship. Fifteen of them were reinforced using steel and plastic meshes. These specimens were tested for in-plane static cyclic diagonal tension (shear) behavior. The critical parameters, such as shear stress, strain, failure modes, ductility, energy dissipation, and stiffness degradation were investigated. Compared to reference and plastic-reinforced specimens, the steel-reinforced samples were found to be highly effective. Furthermore, the recommended category of steel increased the shear capacity, energy dissipation, and ductility ratio by 1.3, 14, and 6.3 times, respectively. [ABSTRACT FROM AUTHOR]

This paper reports the theoretical findings of the new modified type of tuned liquid column ball damper (TLCBD), called a tuned liquid column ball spring damper (TLCBSD). In this new modified form, the ball inside the horizontal section of the damper is attached to the spring. Furthermore, two types of this modified version are proposed, known as a tuned liquid column ball spring sliding damper (TLCBSSD) and a tuned liquid column ball spring rolling damper (TLCBSRD). In the former, the rotational motion of the ball attached to the spring is restricted, whereas in the latter, the ball attached to the spring can translate as well as rotate. Mathematical models and optimum design parameters are formulated for both types. The performance of these new modified damper versions is assessed numerically and subjected to harmonic, seismic, and impulse loadings. The results show that the performance of the newly proposed dampers is relatively better than traditional TLCBDs in harmonic and seismic excitations. The peak response reduction soon after the impact load becomes zero is comparatively better in TLCBSDs over TLCBDs. Overall, the newly proposed passive vibration control devices performed excellently in structure response reduction over TLCBDs. [ABSTRACT FROM AUTHOR]

Unreinforced masonry structures are vulnerable to seismic loading due to their brittle behavior, and must therefore be strengthened. This paper presents the seismic performance of brick masonry strengthened with steel and plastic meshes. For this purpose, twenty masonry wallets of (600 × 600 × 113 mm) were constructed, keeping the same materials and workmanship. Fifteen of them were reinforced using steel and plastic meshes. These specimens were tested for in-plane static cyclic diagonal tension (shear) behavior. The critical parameters, such as shear stress, strain, failure modes, ductility, energy dissipation, and stiffness degradation were investigated. Compared to reference and plastic-reinforced specimens, the steel-reinforced samples were found to be highly effective. Furthermore, the recommended category of steel increased the shear capacity, energy dissipation, and ductility ratio by 1.3, 14, and 6.3 times, respectively.