Strength and Engineering Properties of Cementless Paste Produced by GGBFS and MgO

This study aims to investigate engineering properties of cementless pastes which were produced by reactive magnesium oxide (MgO) and ground granulated blast furnace slag (GGBFS). The mixtures were designed in various levels of MgO at 2.5%, 5%, 7.5%, 10%, 15% and 20% of total binder weight. The slump flow test, compressive strength test, ultrasonic pulse velocity test (UPV) and thermal conductivity test were conducted to examine the engineering properties of the pastes until 28 curing days. The results indicate that the high proportion of MgO causes the decrease of flow-ability of fresh pastes. Increasing MgO content significantly promotes the hydration process and improves the compressive strength and hardened properties of pastes through the UPV and thermal conductivity testing results.