Testing, Validation, and Numerical Modeling of Rammed Earth Construction Materials

Abstract

In recent years, rammed earth is getting more popular due to its environmental benefits mainly in terms of its low carbonic gas emissions compared to conventional concrete construction. In addition to its use in recent construction projects, maintaining the heritage of rammed earth buildings all over the world requires scientific analysis and knowledge in order to evaluate their appropriateness. This technique is considered a cheap way to build as it requires material which is already available on the site. For this reason, rammed earth construction is often used to solve sheltering problems in developing countries. Aesthetically, the horizontal layering varying from red to orange and yellowish-grey make rammed earth an appealing material. Its environmental, economic, and aesthetic components make rammed earth construction a considerable option to meet project requirements. Due to the limited research in modeling rammed earth, this research aims to input rammed earth material into the finite element software “ABAQUS/CAE” and model the behavior of earth samples and walls under compressive load. Samples from a region of Ghazze in Bekaa, Lebanon, were taken and tests were made to meet the recommended properties for rammed earth usage present in previous literatures. These samples were tested for conventional soil properties and then calibrated to validate their adoption in a rammed earth constitutive model in ABAQUS. Several nonlinear modeling techniques were assessed to reach the proper approach for rammed earth numerical simulation, such as Mohr-Coulomb, Drucker-Prager, and Concrete Damage Plasticity (CDP), where CDP converged the most with the experimental test in terms of shape and hardening, compared to the Mohr-Coulomb and Drucker-Prager which do not model the softening behavior of the material.