Case Studies in Construction Materials (Dec 2021)
An analysis of the engineering properties of mortars containing corn cob ash and polypropylene fiber using the Taguchi and Taguchi-based Grey Relational Analysis methods
Abstract
This study investigates the effect of corn cob ash on the mechanical and physical properties of polypropylene fiber-reinforced cement mortars both experimentally and statistically. For this purpose, mortar specimens with different levels of corn cob ash (0 %, 5 %, 10 % and 20 % by volume of cement), polypropylene fiber (0 %, 0.03 %, 0.06 % and 0.1 % by volume), water to cement ratio (0.4, 0.45, 0.5 and 0.6) and cement dosage (350 kg/m3, 400 kg/m3, 450 kg/m3 and 500 kg/m3), were prepared. The compressive strength, flexural tensile strength and porosity value of the specimens produced were determined. In the experimental design, an L16(44) Taguchi orthogonal array was used for each test. The statistical analyses of the experimental results were done in two steps. In the first step, the optimum value for each parameter was determined separately for each test using the Taguchi method. In the second step, Taguchi-based Grey Relational Analysis (TGA) determined the common optimum values for all tests. TGA analysis results indicated that optimum results were obtained in the mortar samples prepared with 0% by volume of polypropylene fiber, a 500 kg/m3 cement dosage, a 0.45 water/cement ratio and 10 % by volume of corn cob ash. Additionally, the impacts of the parameters on the experimental results were ranked by analysis of variance (ANOVA). Accordingly, the most effective parameter was determined to be the water/cement ratio (56 %), followed by the cement dosage (22 %), corn cob ash (9%) and polypropylene fiber (7 %), respectively. It was concluded that the experimental and statistical results were approximately 95 % compatible and it would be appropriate to use Taguchi and TGA methods together in similar studies.
