Benefit analysis on replacing in situ concreting with precast slabs for temporary construction works in pursuing sustainable construction practice

It is well recognised that a significant amount of solid waste is produced from construction work. The increasing generation of construction waste such as used timber formwork, obsolete concrete and packaging, has caused significant pollution to the environment and risen public concern particularly in densely populated cities, such as Hong Kong. The minimization of construction waste has therefore become a pressing issue in pursuing the practice of sustainable construction. This paper shows the betterment of replacing in situ concreting with precast slabs for temporary works to improve sustainable construction performance. Construction waste from the obsolete concrete constitutes a large part of the construction solid waste in a typical building project. The reduction on the obsolescence by using precast slabs can significantly contribute to improving sustainable construction performance. This study identifies cost saving and the betterment of environmental performance by using precast concrete slabs over the in situ concreting. The data used for analysis in the paper were collected from statistics reports and a case study in Hong Kong construction practice. From the case study results, about 43.93%, 64.01% and 70.70% of the cost of using cast in situ concreting can be saved by reusing precast slabs once for temporary works, twice and three times respectively. The findings provide evidence for promoting the use of precast slabs for temporary works, and contribute to the improvement of sustainable construction performance.