Title: Moisture-iInduced Volume Changes in High-Strength Concrete

Author(s): R. Sri Rarindarajah, C. M. Mercer and J. Toth

Publication: Symposium Paper

Volume: 149

Issue:

Appears on pages(s): 475-490

Keywords: blast furnace slag; compressive strength; fly ash; high-strength concretes; moisture; shrinkage; silica fume; volume change; Materials Research

DOI: 10.14359/4095

Date: 10/1/1994

Abstract:
Reports the moisture-induced shrinkage and swelling of high-strength concrete with 28-day cube strengths ranging from 81 to 107 MPa. The concrete mixtures consisted of hydraulic and blends of ordinary portland cement with 35 percent blast furnace slag content, silica fume, or fly ash in different proportions. The results showed that after 460 days of air-drying, shrinkage of high-strength concretes with 3-day water-curing is between 545 and 775 microstrains, depending on the binder materials used. The incremental shrinkage strains between 28 and 460 days for the concretes range from 215 to 285 microstrains. The highest proportion of drying shrinkage recovered was 69 percent of the 460-day shrinkage for concrete with 35 percent slag content, whereas, the control concrete showed the lowest recoverable shrinkage of 57 percent. Drying shrinkage after 100 days for concretes, which are water-cured for 460 days prior to drying, ranged from 39 to 67 percent of the corresponding shrinkage for similar concretes that are initially water-cured for only 3 days. Shrinkage of mature concrete having blended cement with 35 percent slag content is 240 microstrains, which is 39 percent lower than that for the control concrete with ordinary portland cement, although both concretes had compressive strength of about 105 MPa at the beginning of drying. The effect of partially replacing ordinary portland cement with silica fume decreased or increased the shrinkage of concrete, having 3-day water-curing, depending on the silica fume content. However, the shrinkage of concrete, having 460 days' water curing decreased when ordinary portland cement was replaced partially with silica fume up to 15 percent or with 5 percent silica fume and 5 percent fly ash.