An Investigation of the Effect of Different Additives on the Compressive and Flexural Strength of Rammed Earth

Abstract

The main objective of this research is to study the effect of using different additives on the compressive and flexural strength of rammed earth structures. Different ratios of fly ash, and/or cement were added to the soil to identify their influence on the compressive strength. Recycled fiber materials were used to wrap and reinforce the cement-soil specimens in order to enhance the flexural strength of beams and control the cracks and the mode of failure. The study finds that adding cement to soil has significant effect on the soil strength, and it causes a remarkable increase in the strength while adding fly ash does not increase the compressive strength and it results in elastic modulus reduction. Furthermore, it is concluded that wrapping and reinforcing the specimens by burlap cloth or fiber mesh do not improve the flexural strength due to the weak bond with the cement-soil material. However, when a beam is reinforced by glass fiber exhibited improvement in the flexural strength and it experienced a plastic behavior after the proportional limit and it was able to absorb a large amount of energy without failure.