Title: Effect of Source and Amount of Fly Ash on Mechanical and Durability Properties of Concrete

Author(s): Tarun R. Naik, Shiw S. Singh and Bruce Ramme

Publication: Symposium Paper

Volume: 170

Issue:

Appears on pages(s): 157-188

Keywords: Abrasion resistance; chlorides; compressive strength; concretes; fly ash; modulus of elasticity; permeability; scaling; shrinkage; tensile strength.

DOI: 10.14359/6821

Date: 7/1/1997

Abstract:
This research was carried out to evaluate the effects of source and amount of fly ash on s,trength and durabil ity properties of concrete. Mechanical properties considered were compressive strength, tensile strength, tlexural strength, and modulus of elasticity. The durability-related properties considered were: shrinkage, abrasion resistance, air and water permeability , chloride permeability and salt scaling resistance of concrete. A reference concrete was proportioned to attain the 28-day compressive strength of 41 MPa. Three sources of Class C fly ash were used in this work. Fly ash from each source was used at three levels of cement replacements (40, SO, and 60% ) in producing, concrete mixtures. The water-to-cementitious materials ratio was maintained at 0.30 + 0.02 for all mixtures. In general strength and durability-related properties of concrete were considerably affected by both the tly ash source and amount of fly ash. Also, the strength properties and durabi lity for the 40% fly ash mixture were either comparable or superior to the no-tly ash concrete. The salt scaling resistance of fly ash concrete was either comparable to or better than the no-fly ash concrete, except for one source of fly ash at 60% cement replacement level. All the mixtures, with and without tly ash, tested in this investigation conformed to the strength and durability requirements for excellent quality structural grade concretes.