Effect of Geopolymer coating on mild steel

Abstract

Geopolymer paste is synthesized of fly ash and alkaline activators which is sodium hydroxide solution and sodium silicate solution. Geopolymer paste are good in strength, durability and corrosion resistance. The strength and corrosion resistance of geopolymer paste is investigated. Before that, chemical composition of fly ash is carried out by XRF which is determined molarity of sodium hydroxide solution when it be used to synthesized with sodium silicate solution to produce alkaline activators. Fly ash morphology is investigated by using SEM where it showed fly ash particles size is spherical which is contribute to the reactivity if fly ash. OCP testing is carried out to determine the corrosion region of reinforcement bar when it been embedded in geopolymer paste. The testing that held within 14 days showed that reinforment bar is in passivity region in pourbaix diagram. Elcometer 108 is used in adhesion test to determine a strength of geopolymer coating on mild steel. The testing were carried out by 3 days after coating, 7 days after coating and 14 days after coating. XRD is carried out to analysis phase between fly ash, geopolymer paste and mild steel coating with geopolymer paste.