Title: Drying Shrinkage, Curling, and Joint Opening of Slabs-on-Ground

Author(s): Benoit Bissonnette, Emmanuel K. Attiogbe, Matthew A. Miltenberger, and Carl Fortin

Publication: Materials Journal

Volume: 104

Issue: 3

Appears on pages(s): 259-267

Keywords: cracking; creep; curling; drying shrinkage; joint; moisture; reinforcement; slab-on-ground; strain.

DOI: 10.14359/18671

Date: 5/1/2007

Abstract:
This paper summarizes the findings of the first part of a project intended to characterize the curling and joint opening of concrete slabs in a controlled environment, where the investigated variables were the concrete composition (normal- and high-strength concrete) and amount of steel reinforcement (?s = 0, 0.08, and 0.23%). In addition to the curvature with respect to time, different phenomena were monitored on the experimental slabs, such as strains, joint movements, surface cracking, and relative humidity (RH). It was found that curling and joint opening develop early and that the rate at which each develops is proportional to that of drying shrinkage. Besides, reinforcement can cause cracking between joints and high stiffness combined with high shrinkage (drying shrinkage and autogenous shrinkage) can be detrimental to the performance of slabs-on-ground. The results obtained provide unique reference data and overall insight on the behavior of slabs-on-ground.