Influence of SO3 amount in high volume blast furnace slag cement on fire-induced explosive spalling resistance

This paper can be summarized into the following three main points. 1. The increase of sulfur trioxide (SO3) amount in high volume blast furnace slag cement may lend to a higher probability of explosive spalling in fire. 2. The stronger tendency for explosive spalling to occur as the amount of SO3 increases may be due to the increased vapor pressure inside concrete caused by dehydration of ettringite hydrate product in the temperature range of 100-140 °C. 3. The add of 4% or less SO3 can achieve good explosive spalling resistance for the concrete using high volume blast furnace slag cement. © 2019 Architectural Institute of Japan. All rights reserved.