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Abstract: This study aims to determine an optimal recovery time after a participant has exercised to exhaustion in a controlled climatic condition. Ten males and four females volunteers were examined under hot (30°C) and humid (75% relative humidity) environment in a climatic chamber to simulate typical summer outdoor working conditions of construction workers in Hong Kong. The participants (age 31.3 ± 9.3 years; height 168.5 ± 9.8 cm; weight 62.5 ± 7.1 kg; and percentage body fat 22.9 ± 7.2%) performed graded upper body exercise at a target cadence of 70 rotation per minute (RPM) until exhaustion and were recovered inside the climatic chamber until their physiological conditions returned to the pre-exercise level or lower. Physiological Strain Index (PSI) was used as a yardstick to determine the rate of recovery. The physiological conditions of the participants were monitored by recording their ear temperature (to estimate core temperature), heart rate, oxygen consumption, respiratory exchange ratio and Ratings of Perceived Exertion (RPE). It was found that on average a participant could achieve 97% energetic recovery in 40 min; 90% in 35 min; 82% in 30 min; 75% in 25 min; 68% in 20 min; 60% in 15 min; 53% in 10 min; and 46% in 5 min. Linear regression results showed that recovery time is a significant independent variable to determine the rate of recovery (R 2 = 0.95, P < 0.05). Depending on the level of recovery, an optimal recovery time after exhaustion in a hot and humid environment can be determined based on these findings. [Copyright &y& Elsevier]

A construction project is mostly initiated by the needs of the client. In order to satisfy the client’s requirements in terms of time, cost, and quality, various procurement methods are recommended for selection to increase the chance of success for the complex sequence of activities. Design-build (D&B) integrates design and construction to overcome some of the hurdles inherent in the traditional design-bid-build method. It has been extensively used worldwide and its distinctive features are claimed to deal with the problems of the traditional design-bid-build method. An investigation into the determinants of successful D&B projects can therefore help set a benchmark study for industry practitioners to compare their project performance. To better indicate the success level of D&B projects, the writers developed a project success index for D&B projects in the Hong Kong context, which is assessed by the key project performance indicators of time, cost, quality, and functionality. Multiple regression analysis is then applied to show that the project nature, the effective project management action, and the adoption of innovative management approaches are the critical success factors for D&B projects. The identification of success criteria can furnish project participants with indicators to attain success for their D&B projects for benchmarking and control purposes. The predictors for D&B project success were also determined to enrich the knowledge base for the D&B procurement system. [ABSTRACT FROM AUTHOR]

Learning from incidents (LFI) is a process to seek, analyse, and disseminate the severity and causes of incidents, and take corrective measures to prevent the recurrence of similar events. However, the effects of LFI on the learner's safety performance remain unexplored. This study aimed to identify the effects of the major LFI factors on the safety performance of workers. A questionnaire survey was administered among 210 construction workers in China. A factor analysis was conducted to reveal the underlying LFI factors. A stepwise multiple linear regression was performed to analyse the relationship between the underlying LFI factors and safety performance. A Bayesian Network (BN) was further modelled to identify the probabilistic relational network between the underlying LFI factors and safety performance. The results of BN modelling showed that all the underlying factors were important to improve the safety performance of construction workers. Additionally, sensitivity analysis revealed that the two underlying factors-information sharing and utilization and management commitment-had the largest effects on improving workers' safety performance. The proposed BN also helped find out the most efficient strategy to improve workers' safety performance. This research may serve as a useful guide for better implementation of LFI practices in the construction sector.