Title: Durability of High Strength Concrete

Author(s): D. Whiting

Publication: Symposium Paper

Volume: 100

Issue:

Appears on pages(s): 169-186

Keywords: air-entrained concretes; compressive strength; fly ash; concrete durability; curing; freeze-thaw durability; scaling; high-strength concretes; water-reducing agents; Materials Research

DOI: 10.14359/1813

Date: 4/1/1987

Abstract:
Concrete mixtures were designed to nominal 28 day compressive strengths of 6000, 8000, and 10,000 psi (41, 55, and 69 MPa) using mix designs typical of commercial production of high-strength concretes. To produce the higher strength concretes, additions of fly ash (Class C), water reducers, and high-range water reducers were utilized. Concretes were subjected to both moist and air cures. Durability test procedures included rapid freezing and thawing in water, and application of deicing agents. All moist-cured, non-air-entrained concretes performed poorly, exhibiting rapid deterioration, irrespective of strength level. Entrained air contents, measured in the fresh concrete, of 3 to 4 percent were found to be necessary to assure adequate durability when concretes were subjected to freezing and thawing in water. However, moist-cured, air-entrained, high-strength concretes, prepared at 8000 and 10,000 psi (55 and 69 MPa), while performing satisfactorily with respect to freezing and thawing in water, were less resistant to applications of deicing agents than were air-entrained concretes prepared at the lower strength level. This was true even with air contents between 7 and 8 percent in the fresh concrete. Air curing had generally beneficial effects on resistance to freezing and thawing and application of deicing agents to normal strength air-entrained concretes, but had little positive influence on durability of high-strength mixtures. Performance of non-air-entrained concretes during freezing and thawing in water was somewhat improved when given a period of air drying; however, all non-air-entrained concretes performed poorly when exposed to deicing agents.