Study of the behavior in the fresh and hardened state of mortar with BSSFsteel slag

ABSTRACT

In 2017, crude steel production in Brazil was 34.4 million tons, which represents a growth of 9.8% compared to 2016. Despite the economic importance for the country's economy, the steel industry represents a major environmental problem, due to the amount of slag generated in the steel production process. In this sense, the present study aimed to investigate the properties of mortars produced with Baosteel Slag Short Flow (BSSF) steel slag to replace natural sand. The mix investigated was 1:1:6 (cement:lime:aggregate), with volume substitution at 0%, 20%, 40%, 60% and 80%. The tests were: consistency index, density, incorporated air content, squeeze-flow, compressive and flexural strength, dynamic modulus of elasticity, capillary absorption, void index, and potential tensile bond strength. It can be seen that for a consistency index of 260 ± 5 mm, the mortars with BSSF steel slag showed a higher w/c ratio, in addition to higher density of apparent mass in the fresh and hardened state, dynamic modulus of elasticity, capillarity coefficient, void index. The reference mortar also presented water retention and potential adhesion resistance higher than the mortars with BSSF steel slag, while the values of compressive strength and physical properties were similar. It is also worth mentioning the significant increase in the dynamic elasticity modulus in mortars with BSSF steel slag, due to the high specific mass of the slag, which can harm the durability of the coating, due to the reduction of the capacity to absorb deformations.

Keywords
BSSF steel slag; Potential tensile bond strength; Durability; coating mortar