Volume 4, No. 3, 2010
Received: 2010/07/13, Accepted:
Authors:
Salah Altoubat;
Abstract:
Early age creep and shrinkage are primary factors that influence premature cracking of concrete affecting the
durability and performance of concrete structures. Shrinkage of concrete causes tensile stress development
while tensile creep works as a stress relaxing mechanism and relieves part of the stress developed due to
shrinkage. Shrinkage Reducing Admixtures (SRA) have been effectively used to reduce the potential for
cracking, particularly at early age. However, the effects of SRA on stress development and tensile creep
require more testing. This study provides experimental data on early age creep and shrinkage of normal and
high performance concrete. Concrete mixtures with and without SRA were tested using a uniaxail test
configuration that allowed to measure creep and shrinkage under constant load as well as under increasing
load (restrained condition). Concrete containing a Shrinkage Reducing Admixture (SRA) has been evaluated
using a constant load creep-shrinkage test. SRA was added at a dosage rate of 3.71 l/m3 (0.75 gal/yd3). The
results showed that the SRA at the tested dosage significantly reduced the early age shrinkage of concrete.
The results also indicated that the SRA influenced the shrinkage and creep in a different manner.
Keywords:
Concrete, Creep, Shrinkage, SRA.