Research Information System
WASTE AND BIOMASS VALORIZATION, vol.13, no.4, pp.2375-2397, 2022 (SCI-Expanded, Scopus)
The development of alkali-activated magnesium aluminosilicate binders with the use of only soapstone leads to obtaining low strength and unacceptable durability properties. In this paper, the mechanical and durability properties of these binders enhanced through using co-binders as soapstone replacement and adding fiber reinforcement to the mixture. The addition of a mix of various chemical components through the addition of selected co-binders could have multifarious effects on the mechanical strength and durability properties of the mixture. This paper studies the effects of replacing 20% (in wt%) of the soapstone with four different co-binders (metakaolin, lime, stone wool, and silica fume) on the material's properties. In addition, the study investigates the effect of added fiber reinforcement by adding various fiber types (basalt and micro-steel) of different volume fractions (0.5 and 1 in vol%). The changes in material properties were investigated by ultrasonic pulse velocity, mechanical strength (compressive and flexural strength), drying shrinkage, efflorescence rate, and durability (acid attack, high temperature, carbonation, water absorption by immersion and capillary action). Moreover, the effects of the replacement of soapstone with different co-binders were analyzed by thermogravimetric analysis and X-ray diffraction. The results showed that co-binders play a critical role in the hardened state properties of alkali activated soapstone binders (AAS) with metakaolin exhibiting the greatest influence on improving the hardened state properties. Moreover, the addition of fibers to AAS generally enhances the mechanical strength and durability properties and reduces the drying shrinkage and efflorescence rates. Finally, based on the hardened state properties, it is proposed that the developed fiber reinforced AAS incorporating various co-binders have acceptable properties for being used as a construction material.