The Relationship of Temperature and Compressive Strength on Geopolymer Mortar using Fly Ash-Based

Infrastructure development in Indonesia has increased. Therefore, the use of cement has increased as well. For this reason, it is necessary to replace the replacement cement material with environmentally friendly material. Fly ash is one of the waste materials that can be used as a substitute for cement. The purpose of this paper is to determine the compressive strength values of geopolymer mortars using fly ash-based from different Thermal Power Station and to determine the relationship of temperature curing with the compressive strength on geopolymer mortars using fly ash-based. The fly ash used was obtained from two Thermal Power Station in South Sulawesi, Indonesia. The sample is in the form of a cube with 5 cm × 5 cm size, with variations in room temperature; 65°C, 85°C, and 105°C. Activators used were Na 2 SiO 3 and NaOH with 10 M with a ratio of Na 2 SiO 3 per NaOH of 2. Compressive strength tests were carried out at 28 days. From the results of the study that the compressive strength of geopolymer mortar based on fly ash-Thermal Power Station A is higher than the compressive strength value of geopolymer mortar based on fly ash - Thermal Power Station B. The relationship of compressive strength with curing treatment with geopolymer mortar temperature variations is very significant. The higher the temperature, the higher the compressive strength of the mortar.