Current Issue : July-September Volume : 2025 Issue Number : 3 Articles : 5 Articles
The prefabrication and assembly of rebar parts can reduce construction costs and time while enhancing construction quality and safety. The primary objective of this paper is to quantify the overall stiffness of rebar parts. A three-dimensional rotational stiffness solution model of welded spots is proposed from the perspective of revealing the overall stiffness required for welded rebar parts. Considering the influence of the rebar diameter, 105 sets of T-type welded rebar specimens and two types of loading devices were designed, and a graded loading failure test was carried out. On this basis, the constitutive model of welded spots and the method for evaluating the model parameters are presented. Moreover, in order to verify the rationality of the proposed constitutive model and its parameter values, the deformation of welded rebar parts for the middle pylon of Changtai Yangtze River Bridge was tested onsite. The results show that analyzing the three-dimensional rotational stiffness of welded spots is the key to obtaining the overall stiffness of welded rebar parts, and its rotational stiffness decreases rapidly after an elastic platform. The constitutive model parameters of welded spots such as initial stiffness, elastic rotation angle, and stiffness degradation rate conform to Gaussian distribution. When the model parameters of welded spots are taken as the mean value of the distribution function, the simulated values are basically in good agreement with the measured values, with a maximum error of only 8.54%, indicating that the proposed constitutive model can better quantify the overall stiffness of the welded rebar parts....
The built environment directly impacts human health and well-being, yet most green certification systems prioritize energy efficiency over occupant health. The WELL Building Standard (WELL), launched in 2014, addresses this gap by focusing on the health and comfort of building users. Despite its growing importance, limited academic research systematically examines its global implementation. This study will fill this research gap by analyzing 1559 WELL-certified projects worldwide using the WELL database. The results reveal that 50% of certifications are concentrated in China and the United States, while regions such as Africa and Latin America show minimal adoption. Most projects are office buildings (83%), with fewer in education, healthcare and residential sectors. Additionally, most certified projects have achieved Gold or Platinum levels, and there has been a notable increase in certifications since the COVID-19 pandemic. By identifying geographic and typological disparities, this research provides a global overview of WELL adoption and offers insights for practitioners and policymakers seeking to promote healthfocused building practices....
The safety of bridge construction has become a special concern for the Indonesian government since many bridge construction accidents occurred in 2017 and 2018. Construction projects involve a small number of contractor employees, so when conducting accident risk assessments, the results become less accurate. Monte Carlo simulation is a method that can be applied to conduct risk analysis with limited available data. This research began with the identification of potential risks that might occur in bridge construction, resulting in 24 types of risks. Risk assessment was conducted based on the list of risks identified by the contractor’s employees who were working on a bridge project. The results of the risk assessment were then analyzed and prepared for the Monte Carlo simulation process. The simulation results showed accurate outcomes with a total of 10,000 simulations. The greatest risks occur when a worker falls, which has a risk index of 12.5961, and a girder collapses during installation, which has a risk index of 16.1873....
The employment of automated non-destructive testing (NDT) methods for crack characterization in concrete, needs calibration and benchmarking in a controlled environment. This requires test specimen with comparable and ideally reproducible cracks. To this end, in this paper a method is presented that aims to mimic cracked concrete specimens with a high degree of control over the resulting crack parameters width, depth and length for material testing and calibration of automated (NDT) methods. The method comprises 3D-printing of formwork with integrated crack patterns. The obtained crack width accuracy is tested by comparing printed cracks and resulting cracks in the concrete with the desired width from the print file. This procedure enables the realization of crack widths ≥ 0.2 mm with a deviation in the range of 25% between desired and resulting crack width. Further, the proposed methodology is independent of intrinsic material properties which enables this accuracy....
This study assesses the wind resistance and vortex-induced vibration (VIV) risks of the Dongzhou River Bridge in China reconstruction during critical construction stages. Computational Fluid Dynamics (CFD) simulations analyzed wind effects when the twin main girders were maximally separated, revealing asymmetric vortex shedding patterns influenced by upstream–downstream aerodynamic interactions. The upstream girder’s wake generated complex flow fields, increasing turbulence on the downstream girder and indicating elevated VIV susceptibility. A 1:50 scale aeroelastic model validated these findings through wind tunnel tests, confirming that CFD-predicted critical VIV wind speeds aligned with experimental observations. Tests identified a distinct “jump-like” vibration mode at specific wind speeds (35–40 m/s full-scale equivalent), characterized by abrupt amplitude escalation rather than gradual growth—a signature of unstable VIV resonance. However, measured amplitudes remained below the 61.5 mm full-scale equivalent safety threshold, confirming that vibrations posed no critical risk. While aerodynamic coupling between girders requires monitoring during cantilever construction, the study concludes that existing control measures ensure safe construction and operation without structural modifications. These results provide actionable guidelines for wind risk mitigation through construction sequencing and real-time wind speed restrictions....
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