Reinforcement of steel beam-to-double column moment connection using side plates

One of the disadvantages of conventional steel structures in Iran is the common way of I-shaped beam to double column fixed connection that do not perform well against seismic loads. This article uses the side plate to modify and optimize the connection. Using this new geometry, the beam-to-column direct connection is eliminated, and there is no longer any concern about the brittle fracture of penetration weld of the beam-to-column connection and the weakness of panel zone that occur in the common fixed connections. In addition, by eliminating the direct transfer of beam flange force to the double column connection plate, the problem of deformation, complexity or buckling of the cover plate of the column is spontaneously removed. In this paper, in order to investigate the nonlinear behavior of beam-to-double column connection system, a number of three-dimensional finite element models under the effect of cyclic loading have been analyzed. The results show that the beam-to-double column connection using the side plates has good strength and ductility and can be used in special moment frames for seismic areas.

Investigating the Use of Active Transportation Modes Among University Employees Through an Advanced Decision Tree Algorithm

Now more than ever, the health and economic benefits of active transportation (AT) are evident and several planning efforts and programs are particularly targeted at improving active transportation options for different populations, such as students and seniors. Administrative employees at universities received less attention in the literature than other population groups.This population spends a lot of time doing sedentary activities and behaviors during their working time. Thus, the present study used a C5 decision tree to examine the usage of university employees’ AT modes when they are out of campus to get to work, shopping, and leisure. The effects of the sociodemographic and living environment of employees on their AT mode choice were also examined. According to the results, walking was the most frequently used mode to get to work and leisure and public transport was the most frequently used mode to get to shopping. Transit station conditions (25), sidewalk availability and coverage (36), and bike path availability and coverage (30) were the most important factors in the use of AT modes by employees to get to work, shop, and leisure, respectively. Furthermore, several decision rules were extracted from the C5 tree, which included combinations of multiple factors.KEYWORDS: Active transportation, mode choice, university employees, trip purposes, C5

Analysis of Rectangular Reinforced Concrete Liquied Tanks by Using Yield Line Theory

In the analysis of rectangular reinforced liquid storage tanks, a method assuming linear-elastic behavior for material can be used, i.e., the strip method, the moment coefficient method, the finite element method, etc. In the analysis of these types of tanks, tank walls can be considered as slabs. In this study, tank walls were analyzed as slabs subjected to hydrostatic loading; in the analysis, the yield line theory is used because it is more suitable for the linear inelastic behavior of reinforced concrete slabs than the ones based on the linear elastic theory. An iterative algorithm based on yield line theory is presented for the design of isotropically reinforced recrangular concrete slabs supported along all four edges. A computer program is coded which predicts the location of yield lines for the slabs depending upon certain parameters. As a result of this prediction, the manual design of such slabs can be significantly simplified by the use of the coefficient obtained by using the program. It was shown that the analytical computation of the ultimate moment per unit length requires the solution of a highly nonlinear system of equations. This difficulty was overcome by utilizing an iterative technique within the computer program. It also gives the value of the ultimate moment per unit length of the yield line.

A Review on Compressive Strength of Concrete Containing Waste Cathode Ray Tube Glass as Aggregates

The issue of the cathode ray tube (CRT) technology facing its end-of-time and increasing quantities across the globe has acquired the responsiveness of many researchers. The use of waste CRT glass as a construction material has fascinated them due to its significant advantage in recycling the hazardous and non-biodegradable waste CRT glass. However, lack of knowledge about the effects and features of CRT glass as a construction material could be a hindrance to the excessive utilization of waste CRT glass. Therefore, in order to establish the idea of using CRT waste glass as a more common construction material, this paper reviews several recycling techniques of CRT glass and further detail on the workability, density, and compressive strength properties of concrete and mortar using CRT glass (treated or untreated) as fine aggregates. The review showed that, generally, the use of CRT glass as a complete or partial replacement of natural sand shows a slight increase in density, workability, and concrete strength compared to conventional concrete. However, there are no clear trends that can be concluded as this review also showed that various factors influenced its performance, such as percentage replacement, particle size, lead (Pb) content, and types of admixtures.

Overview of Environmental Management Practice for Construction in Malaysia

The surrounding environment plays an important role in communities as living in a good environment can improve the health cycle, increase the quality of life and provide sustainable development for the country. The rapid growth of the human population has led to the increasing demand for infrastructure development and the construction sector in Malaysia. This overview of environmental management practice for construction in Malaysia has reviewed the overall structure of environmental management for the construction site in Malaysia. Construction management is covered in this review report, including construction waste generation, construction waste management, government bodies, government policy, the current status of the environment in Malaysia, challenges, future prospects, and other environmental considerations of environmental management practice for construction in Malaysia. Besides, the detailed guideline and orders for construction waste, effluence discharge, noise pollution, vibration, and emission release from construction in Malaysia have been reviewed and stated in this report. Lastly, a recommendation for strengthening the enforcement of law and regulation for environmental management practice to comply has been included in the conclusion of this report to overcome the challenges faced for sustainable construction development in Malaysia.