A significant body of literature has been dedicated to research studies on construction labor productivity (CLP) and related issues, and a plethora of underlying theories and industrial practices on CLP application has been reported. However, research topics under CLP are highly diversified, and there is a lack of systematic analysis in CLP-related issues. Through a systematic review of selected papers from the well-known academic journals in construction management, major research areas such as factors affecting CLP, CLP modeling and evaluation, method and technology for CLP improvement, CLP trends and comparisons, effect of change/variation on CLP, and baseline/benchmarking CLP are identified. Critical reviews on these areas are presented by focusing on industry, project and activity levels to investigate the state of the art and trends of CLP research. Gaps in research and practices are discussed and future research directions are proposed. The outcomes of this paper may provide a platform for both researchers and industrial practitioners to appreciate the latest development and trend in productivity research.Department of Building and Real Estat

Global warming is bringing more frequent and severe heat waves, and the result will be serious for vulnerable populations such as construction workers. Excessive heat stress has profound effects on physiological responses, which cause occupational injuries, fatalities and low productivity. Construction workers are particularly affected by heat stress, because of the body heat production caused by physically demanding tasks, and hot and humid working conditions. Field studies were conducted between August and September 2016 at two construction training grounds in Hong Kong. Onsite wet-bulb globe temperature (WBGT), workers’ heart rate (HR), and labor productivity were measured and monitored. Based on the 378 data sets of synchronized environmental, physiological, construction labor productivity (CLP), and personal variables, a CLP-heat stress model was established. It was found that WBGT, percentage of maximum HR, age, work duration, and alcohol drinking habits were determining factors for predicting the CLP (adjusted R² = 0.68, p < 0.05). The model revealed that heat stress reduces CLP, with the percentage of direct work time decreasing by 0.33% when the WBGT increased by 1 °C. The findings in this study extend the existing practice notes by providing scientific data that may be of benefit to the industry in producing solid guidelines for working in hot weather.

Department of Building and Real Estat