Effect of the Residual Fine Elements and Contribution on Fresh Properties of Self-Leveling Mortars

Abstract

The self-leveling mortar is a fluid product that has as a low viscosity and high fluidity. This building material that requires no vibration and leveling, having very low thickness (30 mm). The purpose of this study is to evaluate fresh properties of self-leveling SLU using three byproducts: bottom-ashes, fine elements of quarry limestone and fine elements from recycledconcrete-waste. Portland Cement OPC was partially replaced by 0,10, 15 e 20% of fines. The water/binder was maintained constant at 0.50 and mix proportion 1:2 cement and sand (by weight) was used. Fresh properties were examined: plastic shrinkage, curling and heat measurements using a semi-adiabatic calorimeter. A superplasticizer (polycarboxylate) was used to assure a fluidity. During drying (HR=50%) a mass loss was monitored. To the same cement content fine from bottom-ash acted efficiently to reduce a shrinkage. The curling phenomenon is high, with more than 1.70 for mortars based on fine from recycled-concretewaste. Higher early curling was obtained for mortars with quarry limestone. A good performance could be assured with ternary mixes with bottom ashes (curling less than 8mm). Self-leveling mortar systems with more than 20% of fine resulted negative effect on segregation and bleeding, so not recommended to self-leveling mortar purposes.