| Title |
Workability, Compressive Strength and Fire Resistance Characteristics of Cementless Alkali-Activated Lightweight Mortars |
| Authors |
Yang Keun-Hyeok ; Sim Jea-Il ; Lee Seol ; Hwang Hey-Zoo |
| Keywords |
Lightweight Mortar ; Hwangtoh ; Slag ; Flow ; Compressive Strength ; Fire Resistance |
| Abstract |
Sixteen cementless mortars using alkali-activated (AA) hwangtoh (HT) binder or AA ground granulated blast-furnace slag (GGBS) binder were mixed and tested. The main variables investigated were water-binder ratio, lightweight fine aggregate-to-binder ratio, and maximum size of lightweight aggregate. Initial flow and air content were measured in the fresh mortars, and compressive strength development was recoreded in the hardened mortars. In addition, fire resistance of the AA lightweight mortars was evaluated against the variation of water-binder ratio. Test results showed that the workability of AA GGBS lightweight mortars was commonly lower than that of AA HT lightweight mortars. On the other hand, compressive strength of AA GGBS lightweight mortars was greatly higher than that of the company AA HT lightweight mortars. The compressive strength of AA mortars tested increased with the increase of their oven-dry density, showing that higher increasing rate was developed in AA GGBS lightweight mortars than in AA HT lightweight mortars. In addition, higher residual compressive strength ratio under high temperature was observed in AA GGBS lightweight mortars than in the company AA HT lightweight mortars. In particular, the thermal conductivity of AA lightweight mortars was highly lower than that of oridinary portland cement pastes with the same oven-dry density. This indicates that AA GGBS lightweight mortar has the advantage over the fire resistance. |