Defective Reduction from Crack Defects in Cement Paving Tiles

Abstract

The objective of this research is to reduce defects per unit from crack defects of 3.5 cm thickness cement paving tiles. This research adopted the Six Sigma improvement methodology and used the Center Composite Design (CCD) method to find appropriate levels of factors to minimize defects per unit from crack defects. The appropriate levels of factors were obtained by using steel beam concrete shuttle, body concrete shuttle height of 5 mm, facing concrete shuttle height of 5 mm and vibrating production force of 300 kN after improvement, defects per unit was decreased from 0.031 per unit to 0.011 per unit, which was lower than the goal of 0.012 per unit. This improvement is expected to reduce the defective cost of 794,650 Baht per year.