Mechanical Properties and Microstructure of Geopolymer Binder Based on Umeanyar Slatestone Powder

Abstract

This research focuses on the mechanical and microstructure properties of geopolymer binder with slatestone waste as the base material. This geopolymer binder comes from industrial waste crushing slate in the Umeanyar area. This waste is processed into stone powder (USSP) which contains SiO 2 (49%), Al 2 O3 (11%), CaO (11.2%). This USSP uses a sodium hydroxide (SS) activator with a concentration of 14 M. The proportion of the mixture of precursor and activator (P/A) is 70%: 30%; 75%: 25%; 80%: 20% and alkaline activator Na 2 SiO 3 : NaOH (SS/SH) of 1:1; 1.5:1; 2:1, by weight. Samples of specimens were made in the form of a cube with a side of 50 mm and tested at the age of 7 and 28 days. Mechanical properties tested include density and compressive strength based on ASTM-C39. Meanwhile, the microstructural analysis used X-Ray Diffraction (XRD) and Scanning Electronic Microscope-Energy Dispersive X-Ray (SEM-EDX) analysis. The results of the density test were 1.90g/cm 3 and 1.85g/cm 3 respectively and the compressive strength test results were 7.40 MPa and 12.73 MPa at the age of 7 and 28 days, respectively.

Compressive Test and Microstructure Analysis of the Coconut Fiber Ash-based Geopolymer Binder

“…In the third step, after the dough is well mixed, and then prepare a 50-mm cube mold, which has been cleaned previously as shown in Figure 3. The binder mixture is put into a cube mold and wrapped in a plastic bag for 1 day, and continued with the placement of the test object cubes in a heating oven at a temperature of 80 o C for 1 day, removed, and re-wrapped in a plastic bag during the test periods of 7 and 28 days [47]. It should be noted that 3 samples were made for each variation group and the tests were carried out according to the standards of SNI [44] and ASTM [45].…”