Jordan Journal of Civil Engineering

Assessment of Punching Shear Strength of Fiber-Reinforced Concrete Slabs using Factorial Design of Experiments


Nadia Nassif; Waleed Zeiada; Ghazi Al-Khateeb; Salah Haridy;


Design of experiments (DOE) is a systematic method that allows the investigator to design a set of experiments and study the effect of each factor on a response variable .This research proposes an application of design of experiments (DOE) to maximize the punching shear strength of reinforced concrete flat slabs with macro synthetic fibers. An experimental program was developed using two-level factorial (2k) design in which three input factors including fiber content, slab thickness, and steel reinforcement ratio were varied at two levels. The experimental program included seventeen concrete slabs of 1500 x 1500 mm. The main and interactions effects of these factors on the punching shear strength of the fiber reinforced concrete (FRC) slabs were investigated. Using different techniques such as Pareto chart, main effect plot, interaction plot, analysis of variance (ANOVA) and normal probability plot, the experiments were analyzed to determine the significant factors. The results revealed that the slab thickness is the most significant factor affecting the punching shear strength of the FRC slabs. In addition, a linear regression model was developed to predict the punching shear strength of FRC slabs in terms of the most significant factors. The regression model has an R2 value of 99.38%, this ensures that the model is reliable for further prediction. The developed model was validated using previous experimental data from the literature. Results have shown that the model was adequate in predicting the experimental punching shear capacity with a coefficient of variation of 0.18.


Fiber reinforced concrete, Punching shear, Two-level factorial design, Design of Experiments