Experimental investigation of cementitious mixtures with lignocellulosic residue

Abstract

The construction industry, one of the most worldwide important productive and economic activity, is also responsible for environmental impacts like the extraction of raw materials, generation of waste, and cement manufacturing. The main objective of the present work was to study the technical feasibility of applying the residue generated by the second-generation ethanol obtained from sugarcane to partially replace the cement in cementitious mixtures. Characterized as a high lignin residue, it contains a high amount of silica in a weakly polymerized organic structure, and its ashes are a very reactive pozzolanic material. The research sought to obtain answers regarding the performance of the cementitious compositions in the fresh state and in the hardened state. Then, the possible behavior differences between the residue with and without the presence of chemical admixtures were compared. The results showed that there was compatibility between the residue and the selected chemical admixtures; the setting time and the consistency index increased with the presence of the residue; the compressive strength with the residue was lower than the reference composition, but it still demonstrated feasibility; and in some tests carried out, the durability indicators improved in the residue compositions. Thus, the results were very promising and pointed to major developments.