Hydrated lime activation on byproducts for eco-friendly production of structural mortars

Abstract

A new structural mortar that does not contain Portland cement is developed. Ground granulated blast furnace slag is mainly activated by a hydrated lime, and secondary reactions of slag hydration and pozzolanic reaction are promoted by industrial and agricultural byproducts of silica fume and rice-husk ash, respectively. To demonstrate the effectiveness of the proposed production strategy in field conditions, mortars composed mostly of fine aggregates were cured under an air-drying condition of 20 degrees C and 60% relative humidity. As a result, a high compressive strength of 50 MPa was achieved after 28 days of curing. It is found that rice-husk ash can be utilized as a reactive silica source in the developed slag based mortar. From a practical perspective, the mortar can contribute to the wide use of alkali-activated slag composites with reducing the demand for Portland cement and utilizing byproduct of rice husk ash. (C) 2019 Elsevier Ltd. All rights reserved.