การชะละลายของสารละลายในจีโอโพลิเมอร์จากดินลูกรังและเถ้าลอยแคลเซียมสูง

Charoenchai  Ridtirud; Warunvit  Auttha; Thanapol  Promraksa

Authors

Charoenchai Ridtirud Assistant Professor, Civil Engineering Program, Faculty of Engineering, Rajamangala University of Technology Isan, Khon Kaen Campus
Warunvit Auttha Lecturer, Civil Engineering Program, Faculty of Engineering, Rajamangala University of Technology Isan, Khon Kaen Campus.
Thanapol Promraksa Lecturer, Civil Engineering Program, Faculty of Engineering, Rajamangala University of Technology Isan, Khon Kaen Campus

Keywords:

Geopolymer, Leaching, Lateritic soil

Abstract

Geopolymer is a construction material that has gained attention due to its environmental friendliness and the ability to utilize waste materials in its production. However, a significant issue is the leaching of alkaline solutions, such as sodium hydroxide, which may impact ecosystems and human health. This research aims to study the compressive strength and leaching behavior of geopolymer made from lateritic soil mixed with high-calcium fly ash, focusing on varying the concentration of sodium hydroxide and the ratio of sodium silicate to sodium hydroxide. The results showed that a sodium hydroxide concentration of 12 Molar yielded the highest compressive strength, with values of 96.46, 107.18, 110.52, and 117.27 kg/cm² at 3, 7, 14, and 28 days of testing, respectively. Additionally, increasing the sodium silicate to sodium hydroxide ratio improved compressive strength, with a maximum at a 1.50 ratio. However, ratios above 3.00 resulted in rapid setting, leading to a decrease in compressive strength. The leaching study revealed that the pH of the water in which the geopolymer samples were soaked decreased from a maximum of 6.0 to 4.3 at a 12 Molar sodium hydroxide concentration, and the total dissolved solids decreased from 4.337 to 0.965 ppt at 28 days of testing. These findings highlight the importance of controlling the ratio of the solutions in geopolymer production to enhance performance and ensure safety in its application.

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