Properties of self-leveling mortars incorporating a high-volume of sugar cane bagasse ash as partial Portland cement replacement

Self-leveling mortar (SLM) is a special mortar that can flow and fill under its own weight without the need for any compaction energy. To meet these characteristics and to ensure their stability (no segregation and exudation) these mortars require, in addition to proper mixing design and the use of water reducing assets, a large quantity of fines or viscosity modifying additives, which raises the cost for the production. The use of industrial by products such as sugar-cane bagasse ash (SCBA) is an interesting alternative because they are lower cost materials and act as viscosity modifying agent, providing improvements in the rheological, physical and mechanical properties for SLM. Thus, the influence of SCBA on the rheological, physical and mechanical properties of cement-based and limestone filler (LF) mortars will be investigate in this research. The mortars were produced with a water/binder (cement + LF + SCBA) volumetric ratio of 0.85 and 15%, 20%, 25% and 30% Portland cement (PC) replacement by SCBA. An experimental study was conducted to evaluate the effects of SCBA incorporation on the properties of fresh (viscosity, flowability and filling ability) and hardened mortars (flexural strength, compressive strength, dynamic modulus of elasticity, bond strength and water absorption by capillarity). The results show that the rheological, physical and mechanical behavior of mortars was improved, especially for contents of up to 25% replacement of PC by SCBA. For higher contents, the performance of SLM was reduced.