Effects of physical fatigue on the induction of mental fatigue of construction workers: A pilot study based on a neurophysiological approach

Within a dynamic and complex working environment, fatigue statuses (involving physical and mental fatigue) of workers on construction sites tend to have a more serious impact on work performance than general workplaces. To improve safety management on sites, valid fatigue management measures for workers are urgently required. Specifically, there are construction activities requiring both physical and cognitive effort. As a critical premise for putting forward feasible fatigue management measures, correlations between physical and mental fatigue on work performance should be identified. This research explored the effects of physical fatigue on the induction of mental fatigue of construction workers, by adopting a pilot experimental method. Manual handling tasks of different intensities were firstly designed for stimulating certain expected physical fatigue statuses. A cognition-required risk identification task was then arranged for inducing mental fatigue, during which a wearable electroencephalogram (EEG) sensor was utilized for fatigue detection and measurement. Through a comprehensive data analysis method based on EEG rhythms, it was found that the high physical fatigue can significantly accelerate the induction of mental fatigue. Considering the resource allotment, more vigilant and attentional resources were required during the intensive manual handling tasks for the highly controlled limbs and the mind to steps. Thus, additional resources were invested to maintain the same level of cognitive performance in the risk identification tasks, which led to the increased mental fatigue. In practice, the heavy physical task can be regarded as one of the factors affecting the development of mental fatigue status, and therefore impairing cognitive functioning and other mental performances of the brain. The pilot study results provided a reference for fatigue management of construction workers to promote comprehensive safety management on construction sites.