Performance of compressed earth bricks reinforced with sugar industrial by-products bagasse and molasse: Mechanical, physical and durability properties

Abstract

Because sustainable development is a major concern, many studies focus on reducing greenhouse gas emissions during the manufacturing of building materials. Therefore, in this study, we aim to produce lightweight eco-friendly compressed earth bricks (CEB) using industrial sugar by-products, sugarcane bagasse fibers (SCB) and molasse (SCM), as soil stabilizers to diminish the employment of cement. First, we investigated the physical, chemical, and mineralogical composition of the sugar by-products and the used soil. Then, we produced three types of CEB: bricks with soil and SCM (5 wt% and 10 wt%), bricks with soil and SCB (0.5 wt%, 0.75 wt%, and 1 wt%), and bricks with soil, SCB and SCM (this mixture considered two variable parameters: 5 wt% and 10 wt% of SCM, with varying SCB concentrations at three distinct levels: 0,5 wt%, 0.75 wt% and 1 wt%).The results showed that the incorporation of SCM as a stabilizer instead of cement in CEB enhanced both the dry and wet compressive strength, reaching 11.128 MPa and 9.897 MPa, respectively, which represent more than three times the results for the reference soil brick. As to the soil-SCB matrix, the incorporation of SCB decreased the compressive strength by about 36 % (from 3.338 MPa corresponding to reference brick composed only with soil to 2,142 MPa related to bricks stabilized with 1 wt% of SCB). Finally, for the composite soil-SCB-SCM, the highest value obtained was 9.309 MPa related to 10 wt% of SCM and 0.5 wt% of SCB. Moreover, the durability properties including dry abrasion, erosion, and capillarity tests were investigated and compared. The results indicated that SCM has satisfactory durability criteria while bricks stabilized with only SCB showed low resistance, especially to the capillarity test.