Effect of Elevated Temperature on Engineering Properties of Ternary Blended No-cement Mortar

Abstract

This paper aims to examine the engineering properties of ternary blended no-cement mortar which subjected to the various elevated temperatures exposure. The mortars were produced by mixing ground granulated blast furnace slag (S), Type-F fly ash (F) and circulating fluidized bed combustion (CFBC) fly ash (C). The water-to-binder ratio was fixed at 0.40 and the CFBC fly ash content was fixed at 15 wt.% of the mixture that acts as the main activator. The specimens were exposed to the elevated temperatures ranging from 200°C to 800°C. The mass loss, compressive strength, and ultrasonic pulse velocity were determined before and after exposure to the elevated temperatures. The obtained results showed after exposed to high temperature, the mortar weight reduction was discovered in the range of 6.0-8.7% when temperature rose from 200°C to 600°C, and decreased significantly up to 12.4% as temperature reached 800°C. The major strength loss occurred after 600°C with the residual compressive strength approximately at 44.2%. At 200°C, increased strength was found on SFC mixture and when temperature rose to 400°C, the specimens still can resist the load reliably with the strength loss less than 8.0%. Consequently, SFC mortar generates good durability and heat resistance below 400°C.