Stabilization of compressed earth blocks (CEBs) by geopolymer binder based on local materials from Burkina Faso
Résumé
The main objective of this study is to evaluate the feasibility of stabilizing compressed earth blocks with a geopolymer binder that is less polluting than Portland cement. Thus, a performance evaluation of these materials compared to non-stabilized or Portland cement-stabilized earth blocks was the main aim this study. The geopolymer was synthesized from a mixture of metakaolin and sodium hydroxide solution. Laterite formed the principal matrix of the bricks. Compressed Earth Bricks (CEBs) stabilized with 5, 10, 15 and 20% of geopolymer were produced and compared to both CEBs containing 8% of Portland cement and CEBs without stabilizer. After a cure of 14 days for the specimens without stabilizer and geopolymerized CEBs and 21 days for Portland cement-stabilized CEBs, the blocks were subjected to several characterization tests in order to evaluate their properties (physical mechanical and thermal properties). The results showed that geopolymerization of CEBs significantly improved their mechanical performance and gave them thermal properties that were very similar to those of non-stabilized blocks. For a 15% geopolymer content, these materials displayed properties comparable to those of Portland cement-stabilized CEBs, in particular with regard to their stability in water. (C) 2018 Elsevier Ltd. All rights reserved.