DefinePK

Abstract

Polyurethane has widely been used as a ground improvement for several years. The advantages of using polyurethane in ground improvement cannot be denied. Polyurethane foam is a very flexible and lightweight material which is so useful to increase the strength of soil. Polyurethane are used as grouting material in order to remediate settlement and uplifting the effected structure especially foundation to initial position. However polyol that used for polyurethane production are derived from petrochemical based. Concerns over petrochemical raw material volatility and non-sustainable material have caused the interest in substitutes the use of chemical based polyurethane to palm kernel oil-based polyurethane. This study perhaps can contribute to overcome those issues. Particularly, this study involves experimental work to evaluate the strength characteristic for different ratios of palm kernel oil based polyol to isocynate to form palm kernel oil based polyurethane (PKO-PU). The strength was tested using Unconfined Compression Test (UCT) for sample size of 50mm diameter and 100mm height. During mixing, expansions for every ratio were monitored. Stiffness and behavior for every ratio was then being analyzed using stress-strain curve. It is shown that, increasing in amount of polyol result in increasing the expansion but reduction in strength. PKO-PU shows rigid characteristics at the maximum strength which produce strong material, able to resist deformation but brittle beyond the maximum stress. Further increasing amount of polyol, PKO-PU shows flexible characteristic whereby it undergoes deformation but tend to elongate beyond the maximum stress. Higher stiffness and density recorded for rigid PKO-PU compared to flexible type PKO-PU.