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

• Published in: Journal of cleaner production 2019-09, Vol.231, p.1389-1398
• Main Authors: Kang, Sung-Hoon, Kwon, Yang-Hee, Hong, Sung-Gul, Chun, Sungchul, Moon, Juhyuk
• Format: Article
• Language: English
• Subjects: Agricultural by-product; Cementless mortar; Ground granulated blast-furnace slag; Pozzolanic reaction; Rice-husk ash; Sustainable construction materials
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2019.05.313

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 °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. [Display omitted] •New cementless structural mortar was developed without using high alkaline solutions.•The developed mortar shares the production process of ordinary cement mortar.•Included amorphous silica promoted the hydration reaction and strength development.•Processed rice husk ash is more effective in hydration than silica fume as a silica source.