Assessment of Chloride Ion Penetration of Alkali Activated Low Calcium Fly Ash based Geopolymer Concrete

摘要

Fly ash-based geopolymer concrete (GPC) comprised of fly ash, Fine aggregate, coarse aggregate, and an alkaline solution, which is a combination of sodium hydroxide and sodium silicate, can play a significant role with respect to environmental control of greenhouse effects. The reduction in the carbon dioxide emission from cement production can contribute significantly to global temperature reduction. Current studies on geopolymer concrete are primarily focused on geopolymer technology to prepare fly ash-based geopolymer concrete and its Engineering properties determination. However, no specific publications are available with respect to the durability of geopolymer concrete in the marine environment. Corrosion of reinforcing steel due to chloride ingress ion is one of the most common environmental attacks that lead to the deterioration of concrete structures. Therefore, wherever there is a potential risk of chloride induced corrosion, the concrete should be evaluated for chloride permeability. This paper describes an durability testing program, based on Rapid chloride permeability test technique to measure the chloride permeability of in-place concrete. To investigate the durability performance of geopolymer fly ash-based concretes and OPC concretes that have been subjected to natural seawater exposure. A series of 100x50mm specimen were cut from the 100x200mm cylinders of both GPC & OPC to fit them into the test set up. The test results indicated excellent resistance of the geopolymer concrete (GPC) to chloride ingress ion with a less charge passed through them relative to ordinary Portland cement (OPC concrete)