Preposition of a Key Parameter to Estimate the Compressive Strength of the Sand stabilized with cement-zeolite and Reinforced by Polypropylene Fibers

Document Type : Research Article


1 Department of Civil Engineering, Arak Branch, Islamic Azad University, Arak, Iran

2 Department of Civil Engineering, Gonbad KavousUniversity, Gonbad Kavous, Iran


Nowadays, partial cement replacement with natural pozzolans like zeolite and use of reinforcing agents such as fibers have been extensively used in the field of soil stabilization. In the current paper, the effects of incorporation of polypropylene fibers and zeolite in a typical cemented sand have been examined. A set of unconfined compression strength (UCS) tests considering three distinct porosities (related to Dr = 35, 50, 70 and 85% sand), four cement contents (2, 4, 6, 8 and 10%), six different percentages of cement replacement with zeolite (0, 10, 30, 50, 70 and 90%) and the fiber content (0.5% by weight of cement in the mixture) has been performed. Then, the amounts of improved unconfined compressive strength (UCS) of the specimens as the result of zeolite and cement chemical properties have been estimated. Results indicate that the optimum amount of cement replacement by zeolite is 30%. Studies on zeolite-cement-sand mixtures reinforced by fibers have also shown that UCS improves in case cement content (C) and porosity (η) go up. Parameter (SiO2+Al2O3) which are active particles (AP) participate in the chemical reaction introduced and UCS-AP diagrams have been drawn. Afterwards, UCS has been plotted against η/AP which is considered as a controlling parameter of UCS. This experimental research and the parameter η^(-1.79) 〖AP〗^1.43 will introduce an acceptable description of mechanical properties. Finally, the effect of reinforcing agent in the mixture has been thoroughly studied through SEM analysis.