Prediction of strength properties of concrete with jute fibres, kenaf fibers and silica fumes: a response surface methodology (DOE) approach

ABSTRACT

The Design of Experiment (DOE) approach was employed to determine the optimum combination of progression variables, which included Jute fibres (JF), Kenaf fibres (KF), and Silica fumes (SF), aimed at improving the mechanical properties of concrete. To achieve this, the Central composite design (CCD) of Response Surface Methodology was used. The results indicated that the inclusion of KF, JF and SF contributed positively to enhancement of mechanical properties. However, it was observed that a higher level of 0.75% of Jute and kenaf fibres incorporation led to a reduction in strength. The analysis, which involved surface plots, Pareto charts, and regression models, demonstrated that the presence of silica fumes was the most influential factor affecting compressive strength at both 14 days and 28 days. On the other hand, for split tensile strength, both jute and kenaf fibres played significant roles. To assess the accuracy of the models, validation tests were conducted, and the percentage of error was found to be less than 3.5% for compressive strength and split tensile strength. This indicates the reliability of models in predicting the strength properties based on the chosen progression variables.

Keywords:
Jute fibre; Kenaf fibre; Silica fumes; Response surface methodology; Analysis of variance