Title:
Concretes Incorporating High Volumes of ASTM Class F Fly Ashes: Mechanical Properties and Resistance to De-icing Salt Scaling and to Chloride-Ion Penetration
Author(s):
A. Bilodeau and V. M. MalhotraI
Publication:
Symposium Paper
Volume:
132
Issue:
Appears on pages(s):
319-350
Keywords:
abrasion resistance; chloride ions; compressive strength; creep; deicers; drying shrinkage; flexural strength; setting (hardening); fly ash; scaling; modulus of elasticity; superplasticizer; Materials Research
DOI:
10.14359/1884
Date:
5/1/1992
Abstract:
This paper gives the results of an investigation on the performance of high-volume fly ash concrete made with ASTM Class F fly ashes from three different sources. Cementitious materials contents of 300, 370, and 430 kg/m3 were used. The percentage of fly ash used was 58 percent of the total cementitious materials content. All the concrete mixtures were air-entrained and superplasticized. A large number of concrete specimens were subjected to the determination of compressive and flexural strengths, Young's modulus of elasticity, creep strain, drying shrinkage, abrasion resistance, deicing salt-scaling resistance, and resistance to chloride-ion penetration. High-volume fly ash concrete with adequate early-age strengths and excellent later age strengths can be produced with cement and total cementitious materials as low as 125 and 300 kg/m3, respectively. The Young's modulus of elasticity, creep, and drying shrinkage of high-volume concrete are comparable to those of the plain portland cement concrete. The high-volume fly ash concrete shows excellent resistance to chloride-ion penetration and outperforms plain portland cement concrete. The total charge in coloumbs at 91 days, a measure of resistance to the chloride-ion penetration, ranges from 278 to 1078. The corresponding values for reference concrete range from 1003 to 2313. Further research is needed to explain the relatively poor performance of the high-volume fly ash concrete under deicing salt scaling and abrasion tests.