Use of Waste Glass as a Reinforce Material in Calcined-Kaolin Based Geopolymer

Abstract

Geopolymer is widely known as an environmentally-friendly construction material due to the remarkably low emission of CO2 in its manufacturing process. This inorganic polymer can be produced via two precursors: solid component and alkaline activator. In the present work, the studied program was divided into two steps. In Step 1, the molarity of NaOH was investigated. The calcined-kaolin from Lampang city (Thailand source) was used as base alumino-silicate material. In addition, the concentrations of NaOH (5M, 10M, 15M and 20M) were utilized as alkaline activator for geopolymerization. After mixing, the geopolymer slurry was casted into a size of a 50 mm ´ 50 mm ´ 50 mm steel mold. The curing condition of all specimens was maintained at 60°C for 7 days. The compressive strength of all specimens was tested. The utilization of 10M of NaOH yielded the highest compressive strength with the value of 22.01 MPa. In Step 2, 10M of NaOH was fixed and used as alkaline activator. In this case, the amount of waste glass (0%, 10%, 20%, 30%, 40% and 50% by weight) was studied on partial calcined-kaolin replacement. However, the compressive strength of all samples slightly changed with an increasing weight percentage of waste glass (0% - 20 %). The highest compressive strength of 20 wt% waste glass was 25.22 MPa. Although, all samples showed a Si-O-Al bond in the FTIR result, indicating the geopolymer degree strenghened. However, the compressive strength of samples tended to decrease with an increase in the amount of waste glass (30 to 50 wt%) as a result of micro-cracks observed and distributed in the samples.

Evaluation of Physical Properties of a Metakaolin-Based Alkali-Activated Binder Containing Waste Foam Glass

“…Anatase is due to the presence of TiO 2 in MK (Table 1); the latter two phases are clay relics which had not been decomposed during the thermal activation of the original kaolinitic clay [7]. WFG was found to be totally amorphous, as expected [11,12,20,28]. The XRPD pattern of the MK100 sample points to a largely amorphous material containing quartz and kaolinite inclusions, consistent with previous results on metakaolin-based alkali-activated binders [7,29], as well as traces of anatase.…”

“…The spectrum of WFG comprises typical bands for a glass [20,22], i.e., asymmetric stretching vibration of Si-O-Si and Si-O-Al bonds (952 cm −1 ), and symmetric stretching vibration of Si-O-Si bonds (767 cm −1 ). The FTIR spectrum of MK indicates a main contribution by the asymmetric stretching vibration of Si-O-Si and Si-O-Al bonds at 1029 cm −1 [12,22,30]. Most of the silicon sites are present in a 2D sheet consisting mainly of Q 4 (1Al) environments, thus Si-O-Si bonds are considered to contribute the most to this signal [31,32].…”

“…FTIR spectra obtained for WFG, MK and for the produced composites are shown in Figure 3. The spectrum of WFG comprises typical bands for a glass [20,22] [12,22,30]. Most of the silicon sites are present in a 2D sheet consisting mainly of Q 4 (1Al) environments, thus Si-O-Si bonds are considered to contribute the most to this signal [31,32].…”

“…Several studies [11][12][13][14][15][16][17][18][19][20][21][22][23] have investigated the utilization of waste glass in the production of alkali-activated materials, in combination with different aluminosilicate raw materials (metakaolin, fly ash and blast furnace slag). Common sources of waste glass included foam glass, glass cullets, solar panel glass, old glass bottles, municipal waste glass and fluorescent lamps at the end of their service life.…”

“…In these studies, waste glass either played the role of aggregate/filler [12][13][14][15][16][17] or functioned as a precursor for geopolymerization [11,[14][15][16][18][19][20][21], while it was also employed for the preparation of the alkali activators [22,23]. Previous studies have shown that the incorporation of increasing amounts of waste glass in alkali-activated materials caused a decrease in the mechanical properties, attributed to the increase in Si/Al ratio achieved by its use [11], solid-to-liquid ratio [13], mean particle size [15] and micro-cracks formed in the matrix [12]. Furthermore, decrease in density and increase in porosity have been also observed [13,17].…”