Evaluation of the mechanical properties of sea sand-based geopolymer concrete and the corrosion of embedded steel bar. (30th April 2018)

• Record Type: Journal Article
• Authors: Nguyen, Khoa Tan; Le, Tuan Anh; Lee, Kihak
• Is Part Of: Construction & building materials. Volume 169(2018)
• Page Start: 462
• Page End: 472
• Publication Date: 2018-04-30
• Subjects: Geopolymer concrete -- Sea sand -- Microstructure -- Cebelcor cyclic -- Half-cell potential test; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2018.02.169
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: The compressive strength of geopolymer concrete using sea sand as fine aggregate reaches the highest value at an alkaline to fly ash ratio of 0.35–0.45. For sea sand based geopolymer concrete, when the ratio of aggregate to fly ash is low, the compressive strength enhances high value. The difference in strength between specimens using river sand and sea sand is not significant. It takes more time for steel bar in geopolymer concrete using sea sand to be attacked and corroded, compared with the steel bar in normal concrete. Abstract: Portland cement concrete is a major construction and building material used all over the world. It is a composite material comprising Portland cement, coarse aggregate, fine aggregate, and water. But its increased use in construction is exhausting natural resources used in its production, making it necessary to find alternative materials. One potential method is to use sea sand as fine aggregate to produce fly ash based geopolymer concrete. In this paper, the mechanical properties of geopolymer concrete prepared with sea sand as the fine aggregate, and the corrosion of steel bar embedded in the concrete subjected to accelerated corrosion tests, were investigated. The test data revealed that for sea sand based geopolymer concrete, the compressive strength reached high values at an alkaline to fly ash ratio of 0.35–0.45. The geopolymer concrete exhibited highcompressive strength with a low aggregate to fly ash ratio. Also, there was an increase in compressive strength when the Si/Al ratio changed from 1.16 to 1.67. Furthermore, very little difference was observed between the mechanical properties of geopolymer concrete using sea sand, and river sand. Measurements of the corrosion of steel bar using a half-cell potential survey indicated that the steel in geopolymer concrete with sea sand was attacked and corroded like normal concrete. However, the potential of steel bar in geopolymer concrete was higher than in Portland cement concrete.