Application of Tagushi design in quality improvement for construction industry

This study aims to utilize Tagushi design in quality improvement for construction industry. A comparison between full factorial and Tagushi design is conducted experimentally. The experiment investigates the effect of four major factors and their interactions on concrete compression strength. The factors are; percentage of recycled aggregates, percentage of dune sand, amount of steel fiber in concrete mixture and test time. Two types of design of experiments (DOE) have been done to test different concrete mixtures by using different combinations of the mentioned four factors. The collected data has been studied using full factorial and Taguchi “Robust“ designs. Also, Minitab software results have been obtained and analyzed. Based on full factorial design, it was found that all factors were significant, whereas the interactions between factors were significant only for two-way interaction. The three-way and four-way interactions were insignificant. On the other hand, Taguchi analysis was used to determine the main effects of factors. The results of both full factorial and Taguchi methods were the same except for the percentage of dune sand. In the full factorial method, when combining both types of sand, the compressive strength of concrete increased. In contrast, Taguchi showed opposites results.