Title: Durability of Class C Fly Ash-Based Alkali Activated Concrete

Author(s): Eslam Y. Gomaa, Ahmed A. Gheni, and Mohamed A. ElGawady

Publication: Symposium Paper

Volume: 334

Issue:

Appears on pages(s): 185-204

Keywords: Class C fly ash; slag; crumb rubber; alkali activated concrete; fresh properties; compressive strength; durability; ambient curing; oven curing

DOI: 10.14359/51720261

Date: 9/30/2019

Abstract:
The durability of alkali activated concrete (AAC) synthesized using high calcium fly ashes (FAs) was studied. Surface resistivity, bulk electrical resistivity, rapid chloride ions penetration, and freeze-thaw resistance tests were carried out on AAC made with five different FAs. The specimens were either oven-or moist-cured. The effect of adding air entraining admixture (AEA) and recycled crumb rubber to the AAC specimens on the freeze-thaw resistance was investigated as well. It was found that the durability of AAC was higher than that of comparable ordinary Portland cement (OPC) concrete. Adding the AEA improved the freeze-thaw resistance but not enough to complete the 300 cycles, per ASTM C666-15. Adding the rubber to the AAC mixtures improved the freeze-thaw resistance significantly.