Mechanical characterization of lime-stabilized rammed earth: Lime content and strength development

Abstract

Earth construction techniques, such as rammed earth, are present worldwide due to the availability of the material and its mechanical performance. Today they are also attracting attention as an environmentally friendly way of building, although additivation is usually needed. Lime stabilization is an interesting option with long tradition, well-known capacity to improve soil properties and limited environmental impact. This study evaluates the effect of increasing lime contents in the compressive strength and stiffness of rammed earth, and analyzes the strength development process of the material. Carbonation depth and ultrasonic pulse velocity are also evaluated due to their relationship with the mechanical behavior. The results show that 12 % lime maximized the compressive strength and stiffness of the rammed earth material; the strength was mostly developed during the first month but needs over a hundred days to be fully developed. A good linear correlation between the ultrasonic pulse velocity and the compressive strength is observed. • Lime stabilization improves rammed earth strength and stiffness. • There exists an optimum lime content that must be evaluated before construction. • Compressive strength and stiffness follow an exponential development over time. • Long curing periods, over 100 days, needed to develop maximum strength. • UPV tests are useful to estimate the mechanical properties of rammed earth.