HUMAN ERROR PROBABILITIES FOR STRUCTURAL DETAILINGS IN REINFORCED CONCRETE BUILDINGS

Abstract

Human errors in construction works have led to collapse of many buildings more than the error in the planning and design phases as supported by some expert findings. This study reports the findings of human errors due to reinforcement detailings on some selected reinforced concrete building projects in Lagos and Osun States, Nigeria. Ten buildings under construction were visited and physical measurements relating to reinforcement detailings on slabs, beams and columns were taken, the differences between the requirements in the structural drawings and the as- built on the sites were recorded. The probability of error in spacing, sizes and the required number of reinforcing bars for each of the basic structural elements of a building were calculated. The results showed that bar spacing formed the major human error in reinforcement detailing of slabs on all the selected sites. For beams, most of all the sites visited showed significant error in the required number of bars and the spacing of links. It was established that the spacing of links was a general and common human error in the reinforcement detailing of columns. In relation to quality assurance of future reinforcement detailing, the contractors that handled sites 6, 7 and 10 for slabs, beams and columns would be highly disqualified while site 3 was adjudged the best for all the parameters considered.