Setting time of coconut fiber ash-based geopolymer binder

This watchfulness goal is to decide the beginning and ending binding of geopolymer binders using coconut fiber ash (CFA). Experiments were carried out by comparing the effects of ratio precursors and base activators on geopolymer binders. The precursor material is derived from CFA, which consists of 8.24% silicon dioxide, 2.3% diphosphate pentaoxide, 70.6% potassium oxide, 2.25% iron dioxide, and 14.1% chlorine. Using two types of alkaline activators, namely NaOH (SH) with a molar concentration of 14M and Na2SiO3 (SS), which is used as a solution in the manufacturing process. A comparison of the precursor and alkaline activator mixtures with three variations, namely 70%:30%, 75%:25%, and 80%:20%, with SS/SH 1:1, 1.5, and 2:1 ratio by weight. The specimens are cast in a vicat ring with the top and bottom diameters ∅60mm and ∅70mm, as well as a height of 40mm. The setting time test standard used is SNI 2049:2015. The results showed that the beginning and ending binding times of the geopolymer binder got shorter as the P/A and SS/SH got higher, with times 5%–20% decreased on average.