The Effects of Na₂SiO₃/NaOH Ratios on the Volumetric Properties of Fly Ash Geopolymer Artificial Aggregates

Abstract

This study was conducted as a part of a research to assess the influence of the volumetric properties of geopolymer artificial aggregates made of fly ash to the performance of asphalt mixture to be used in pavement layers. This paper presents the parameters adopted during the production of geopolymer artificial aggregates which may affect the volumetric properties and the structure of the aggregates. The investigated volumetric properties included specific gravity and water absorption. In the experiment laboratory, two variables were utilized for producing the artificial aggregates, which might affect the considered volumetric properties. Those variables are pan-granulator slopes and alkaline ratios (the ratios of Sodium Silicate to Sodium Hydroxide). The pan-granulator slopes were set at 3 different angles, i.e. 45o, 50o, and 55o. The selected alkaline ratios were 1.5, 2.0, 2.5, and 3.0. The test results indicated that the best volumetric properties were obtained at a slope of 50o and alkaline ratio of 2.5. The bulk specific gravity values at the best volumetric properties were found to be: 1) oven dry at 1.9 grams/cm3; 2) saturated surface dry (SSD) at 2.0 grams/cm3, and 3) apparent at 2.1 grams/cm3 with 6% water absorption. In addition, the interfacial transition zone and microstructure aggregates were examined by using Scanning Electron Microscope (SEM). In this study, it was found that there were effects of Na2SiO3/ NaOH ratios and the granulation method on the volumetric properties.

Artificial Lightweight Aggregates Made from Pozzolanic Material: A Review on the Method, Physical and Mechanical Properties, Thermal and Microstructure

“…The denser matrix that is shown in Figure 5 for geopolymer aggregate with the solid-to-liquid (fly ash/alkaline activator) ratio of 3.0 results in a lower AIV value, where the strength of the geopolymer aggregate is higher. The geopolymer aggregates indicated that excellent solidification of the fly ash with alkaline activators occurred by geopolymerization reaction as the alkaline activator dissolved most of the fly ash particles [ 79 ]. Furthermore, the SEM of quarry tailings autoclaved aggregate in Figure 6 showed that high stream curing had a denser structure, which increased the strength alongside with reduced water absorption of the aggregate [ 37 ].…”

Pelatihan Pembuatan Panel Geopolimer Fly Ash Di Desa Suranadi Sebagai Pengganti Papan Kayu

“…Penggunaan geopolimer sebagai agregat menunjukkan nilai absorpsi yang tinggi. Terendah sebesar 6,1% didapatkan pada rasio sodium silikat dan sodium hidroksida 2,5 (Karyawan et al, 2019).…”

“…Rasio alkali yang sama, menghasilkan karakteristik mekanis dan mikrostruktur agregat geopolimer fly ash terbaik (Karyawan et al, 2020). Ide menggunakan tanah liat ini sebagai bahan yang direkomendasikan kepada tukang dan pengelola tempat penginapan, muncul berdasarkan hasil penelitian menggunakan lumpur Sidoarjo.…”

Impact Curing Time and Compaction Methods to the Performance of Hot Mix Asphalt Asbuton

“…The resistance to cracking of SMA can be increased by the use of RAP and SWP of up to 12% [1]. The application of fly ash as an artificial aggregate [2], [3], has the potential as a partial substitute for natural aggregate [4], with skid resistance that meets the requirements of roads in urban areas with traffic speeds below 95 km/hour [5]. Recently, the utilize of natural asphalt in the form of rock asphalt containing aggregates and asphalt was developed as a road pavement material.…”