Title:
Long-Term Creep and Shrinkage in High-Strength Lightweight Concrete
Author(s):
M. Lopez, L. Kahn, K. Kurtis, and B. Buchberg
Publication:
Symposium Paper
Volume:
227
Issue:
Appears on pages(s):
317-336
Keywords:
creep; high-performance; high-strength; lightweight concrete; modeling; shrinkage
DOI:
10.14359/14437
Date:
3/1/2005
Abstract:
Creep and shrinkage data for two high strength lightweight aggregate concretes were collected over a two-year period. The concretes, with unit weight of 1922 kg/m3 (120 pcf), were developed using expanded slate as coarse aggregate. Strengths of 55.2 MPa (8,000-psi) and 69.0 MPa (10,000-psi) were obtained at 56 days. Creep specimens were loaded to 40 or 60 percent of the initial compressive strength at 16 or 24 hours after casting. Based on this preliminary study, AASHTO-LRFD creep estimates of high strength, lightweight aggregate concrete were within 20% accuracy for ages later than one month. ACI-209 estimated creep of the 55.2 MPa lightweight concrete and shrinkage of the 69.0 MPa concrete within 20% accuracy, but greatly underestimated shrinkage of the 55.2 MPa mix. When compared with normal weight, high strength concrete of similar strength and similar cement paste content from previous research, the 69.0 MPa lightweight mix experienced lower total strain after two years.