Analisa Sifat Mekanik Mortar Geopolimer POFA dan GGBFS dengan Berbagai Variasi Molaritas pada Suhu Ruang

Abstract

The cement industry has a negative impact on the environment because it contributes to climate change by contributing around 1 ton of CO2 gas emissions into the air. The push for sustainable construction solutions makes the use of geopolymers an environmentally friendly alternative to achieve the net zero target in the Paris agreement. Palm shell waste such as POFA and waste from the steel industry such as GGBFS can be used as pozzolan material to replace cement in geopolymer concrete. This research aims to analyze the mechanical properties of POFA and GGBFS based geopolymer mortar with various variations in molarity at room temperature. This research method is an experimental study with cube and briquette test objects with POFA and GGBFS material variations of 50:50, 60:40, 70:30, 80:20, 90:10 and 100:0 using molarity variations of 8 M, 10 M, 12 M and 14 M which were left at room temperature for 28 and 56 days. In the research, compressive strength tests were carried out on cube specimens and tensile strength of briquette specimens. The composition of briquette mortar uses optimum variations from the compressive strength results of cube mortar. The results of the research showed that the maximum compressive strength occurred in the 50% POFA variation: 50% GGBFS with 14 M NaOH aged 56 days of 43.47 MPa and the minimum compressive strength occurred in 100% POFA with 8 M NaOH aged 28 days of 5.87 MPa. The maximum tensile strength value occurs in the 50% POFA variation: GGBFS 50% NaOH 14 M of 6.35 MPa and the minimum is 4.45 MPa in the 8 M NaOH variation. Based on the test results it can be concluded that the variations in the POFA and GGBFS mixture and the NaOH variations can increasing the compressive strength and tensile strength of geopolymer mortar which is directly proportional to the mortar consistency and mortar setting time. Meanwhile, the treatment period provides gradual results.