Towards compressive strength prediction of earth in real condition: Influence of moisture

Abstract

Earth is being rediscovered as a sustainable building material. Along with many advantages, earth brings the challenge of a large variability in composition and therefore characteristics for building with it. Therefore, being able to predict the compressive strength of earth in real condition is very desirable. In literature, a correlation between dry density, methylene blue value and compressive strength has been found. This relationship is herein researched more thoroughly, especially studying the influence of moisture as it is an ever present factor to earth construction. In this thesis, in a first step a mix design is developed by doing a series of tests, studying the influence of compaction and water content on the dry density and compressive strength. Then, different drying conditions are used on the chosen mixes, researching the relationship of dry density, compressive strength and methylene blue value under the influence of moisture. Results show, that there seems to be a power-law relationship between dry density and compressive strength. Moisture lowers the compressive strength, its impact increasing with increasing dry density. Finally, an equation is fit to describe the behavior, which could be generalized to use as an assessment tool for the compressive strength of earth in real condition.