Title:
Corrosion and Service Life Estimates for Internally Cured Concrete
Author(s):
Kambiz Raoufi and W. Jason Weiss
Publication:
Symposium Paper
Volume:
290
Issue:
Appears on pages(s):
1-16
Keywords:
corrosion, cracking, internal curing, lightweight aggregate, restraint.
DOI:
10.14359/51684180
Date:
9/14/2012
Abstract:
High performance concrete (HPC) mixtures may be prone to early-age cracking. While uncracked HPC can protect steel reinforcement from corrosion reasonably well, cracking can dramatically accelerate the corrosion of reinforcement and reduce the service-life of structures. Several approaches have been developed to reduce the risk of cracking. One of these approaches is internal curing (IC) which uses prewetted lightweight aggregate. This paper describes a series of experiments performed using full-scale restrained concrete elements in an effort to quantify the performance of internally cured concrete on reducing the early-age shrinkage cracking thereby increasing the resistance to corrosion. The results show that concrete made using internal curing experienced a slight swelling at early-ages and experienced very little shrinkage. As a result the IC concrete did not crack while the conventional concrete cracked. Upon exposure to a chloride solution, extensive and nearly immediate corrosion activity was detected in the plain specimen while the internally-cured concrete did not exhibit any cracking or signs of corrosion during the time of this study (approximately 1 year). The benefits of internal curing are reduced cracking as well as reduced transport properties.