Two-stage design method for base isolation structures includes simplified estimation and time history analysis. Simplified estimation is used in preliminary design stage for estimating the weight and the first period of an isolated structure, the upper structure is simplified as a SDOF system. According to the expected response reduction goals and response spectrum, the first period of the isolated structure, stiffness of isolation device and number of isolation bearing can be induced. Time history analysis is employed in detail design stage, for determination and optimization of isolation device based on current standards. The author has made it realized based on the old Seismic Code. As there are some changes of provision on base isolation analysis in new code, including the value of bearing stiffness and safety factor, etc., the method mentioned above should be updated. Numerical investigation shows that for regular multi-storey frame structures, the difference of the maxium ratio of floor shear between the old and new Seismic Code increase with fortification intensity.

The Two-Stage Design Method of Isolated Structures Based on New Code for Seismic Design of Buildings

Experimental, DFT and MD evaluation of Nandina domestica Thunb. extract as green inhibitor for carbon steel corrosion in acidic medium

In recent times, the applications of fiber-reinforced recycled aggregate concrete (FRAC) in practical engineering have gained greater popularity due to its superior mechanical strength and fracture properties. To apply FRAC in buildings and other infrastructures, a thorough understanding of its residual mechanical properties and durability after exposure to fire is highly important. According to the established research, the properties and volume fractions of reinforcing fiber materials, replacement levels of recycled concrete aggregate (RCA), and heating condition would affect the thermal–mechanical properties of FRAC. This review paper aims to present a thorough and updated review of the mechanical performance at an elevated temperature and post-fire durability of FRAC reinforced with various types of fiber material, specifically steel fiber (SF), polypropylene (PP) fiber, and basalt fiber (BF). More explicitly, in this review article the residual mechanical properties of FRAC, such as compressive strength, splitting tensile capacity, modulus of elasticity, mass loss, spalling, and durability after exposure to elevated temperatures, are discussed. Furthermore, this study also encompasses the relationship among the dosages of fibers, replacement levels of recycled aggregate, and the relative residual mechanical properties of FRAC that would help in the optimum selection of the fiber content. Conclusively, this study elaborately reviews and summarizes the relevant and recent literature on recycled aggregate concrete containing SF, PP fiber, and BF. The study further provides a realistic comparison of these fibers in terms of the residual mechanical performance and durability of FRAC that would help in their future enhancements and applications in practical engineering.

https://www.mdpi.com/2075-5309/12/4/487/pdf?version=1649937769

Influence of Elevated Temperatures on the Mechanical Performance of Sustainable-Fiber-Reinforced Recycled Aggregate Concrete: A Review

Choline amino acid ionic liquids as green corrosion inhibitors of mild steel in acidic medium

Insight into the anti–corrosion behavior of Reineckia Carnea leaves extract as an eco–friendly and high–efficiency corrosion inhibitor

Insight into the anti–corrosion performance of Artemisia argyi leaves extract as eco–friendly corrosion inhibitor for carbon steel in HCl medium

Insight into anti–corrosion behavior of Centipeda minima leaves extract as high–efficiency and eco–friendly inhibitor

In order to solve the problem of black pollution in the 21st century, a new type of rubber ceramsite concrete was prepared by pulverizing waste rubber tires into granules and adding aggregate to the ceramsite concrete. In order to reduce the weakening of mechanical properties of rubber, basalt fiber was used to modify the rubber. In this study, the compressive strength and splitting tensile strength of concrete specimens at days 3 and 28 were measured, the variation rule of compressive strength was explained based on the appearance of the microstructure, and the internal porosity of cubic specimens was characterized by the water absorption size. At the same time, an ultrasonic wave velocity test was used to test the uniformity and pore distribution of the block. The results showed that, with the increase in the rubber content, the compressive strength of rubber ceramsite concrete increases first and then decreases. The addition of basalt fiber can improve the compressive strength of the concrete. Water absorption is negatively correlated with compressive strength. Porosity is also negatively correlated with ultrasonic wave velocity. The basalt fiber length has no significant effect on the splitting tensile strength.

/pdf/a-study-on-the-mechanical-properties-and-microcosmic-2i95t2de.pdf

A Study on the Mechanical Properties and Microcosmic Mechanism of Basalt Fiber Modified Rubber Ceramsite Concrete

Expanded polystyrene (EPS) concrete is commonly used as the core material of commercial sandwich panels (CSPs). It is environmentally friendly and lightweight but has poor strength. Adding fibers can improve the microstructure of EPS concrete and reduce the weakening effect of EPS beads on the mechanical properties of concrete. An orthogonal experimental design (OED) was used in this paper to analyze the influence of length and content of polypropylene fiber (PF), glass fiber (GF), and carbon fiber (CF) on the physical and mechanical properties and micromorphology of EPS concrete. Among them, CFs have the most apparent impact on concrete and produce the most significant improvements in all properties. According to the requirements of the flexural performance of CSPs, the splitting tensile strength was taken as the optimization index, and the predicted optimal combination (OC) of EPS concrete with fibers was selected. The variations in the material properties, mechanical properties, and microstructure with age were analyzed. The results show that with increasing age, the dry density, compressive strength, and splitting tensile strength of concrete are markedly improved relative to those of the CSP core material and the control case (CC), and even the degree of hydration is improved.

https://www.mdpi.com/1996-1944/15/3/1228/pdf?version=1644395476

Zhi Miao Yan

Papers

Insight into the anti–corrosion performance of Artemisia argyi leaves extract as eco–friendly corrosion inhibitor for carbon steel in HCl medium

Insight into anti–corrosion behavior of Centipeda minima leaves extract as high–efficiency and eco–friendly inhibitor

A Study on the Mechanical Properties and Microcosmic Mechanism of Basalt Fiber Modified Rubber Ceramsite Concrete

Insight into the anti–corrosion behavior of Reineckia Carnea leaves extract as an eco–friendly and high–efficiency corrosion inhibitor

An Investigation of the Properties of Expanded Polystyrene Concrete with Fibers Based on an Orthogonal Experimental Design