A study of scrap material amounts and precast productivity improvement in two floor single detached house precast manufacture by Five Minutes Rating Method

Abstract

In current situations, problems in housing construction are found in three categories which are insufficient labor, shortage of skillful labors, and quality of work. These problems lead to the delay in housing construction. To reduce such problems, prefabrication housing system is selected for construction of housing projects. This study has three objectives which are to study construction productivity, to improve productivity, and to study the scrap materials from the precast processing. Data was collected from a production line of two-floor-single-detached-house in a precast factory. Five Minutes Rating method was used to investigate productivity rate. Four groups of labors performing concrete activity are samples of this study. Productivity of labors before the improvement of the four groups are 72%, 89%, 77%, and 88%, respectively. After the improvement, the productivity are 87%, 89%, 84%, and 91%, respectively. On the other hand, waste of materials were found related to 6 mm. and 8 mm. wire meshes used in the precast production. Scrap materials were found for 6 mm. and 8 mm. wire meshes for 18% and 23%, respectively. Moreover, insufficient of equipment also causes waiting time and delay in construction, as well.