Evaluation of concrete work strain in buildings construction

The activities associated with construction industry are strenuous and cause health hazardous problem. A field study was conducted to investigate job strain among concrete workers in buildings construction. Twenty one concrete workers participated in this study. Three types of concrete task were: getting, handling, and pouring concrete mixture. Concrete mixture handling and pouring were performed in horizontal and vertical directions. Job Strain Index was used to estimate injury risks, whereas OVAKO Working Posture Analysis System (OWAS) was used to evaluate postural load during work. Moreover, Standardized Nordic questionnaire was used to evaluate musculoskeletal symptoms of the subjects. To compare the physical workload of concrete handling in different directions, heart rate was measured and analyzed. The results showed that the job strain index were 3 and below indicating that the concrete tasks were safe. The OWAS results rated postures of handling and pouring tasks for horizontal handling and getting task for vertical handling in action category 4, which indicated extremely deleterious effect and change required immediately. The results of Standardized Nordic questionnaire revealed that the most commonly affected parts among the workers were lower back, thigh, shoulders and wrists/hands. The greatest increased heart rate was found in the pouring task. The vertical handling showed greater increased heart rate than the horizontal heart rate. It can be concluded that concrete work can place injury risks to concrete workers.