Stabilized Soil as a Sustainable Construction Material Using the Rammed Earth Technique

Abstract

Cementitious construction materials are generally energy-intensive with the inevitable addition of CO2 to the global environment. To address this problem, few researchers are been working on developing alternative sustainable construction materials. One such approach is the use of soil as a construction material by rammed earth construction technique. The main drawback of this technique is its lower durability. The present work is an attempt to stabilize locally available soils to make them suitable for rammed earth construction. The objective of the study is to check the viability of three different locally available natural soils with variable index and engineering characteristics for sustainable rammed earth wall construction. However, all available natural soils do not have the adequate strength necessary for construction. So the need for its stabilization to improve their mechanical properties becomes inevitable. In this study, admixture stabilization was adopted. The influence of varying percentages of two stabilizers, Portland cement (for binder strength) and lime (only with black cotton soil as a pre-stabilizer), is studied. To improve the tensile properties of stabilized soil, polypropylene fiber (PPE) was added. Unconfined compressive strength and split tension tests were carried out on both wet and soaked specimens at 14 days and 28 days curing period. Experimental outcomes demonstrate that chosen soils become viable construction materials and are durable by satisfying the standard strength of 2 MPa. However, for black cotton soil, 3% lime stabilization before cement stabilization is required. When fiber is used along with admixtures stabilization, the target strength can be obtained right from 14 days curing period with 0.4% fiber content in the soils.KeywordsGreen buildingSustainable materialAdmixture stabilization