Comparative Analysis on Reducing Concrete Shrinkage and Cracking
Can concrete shrinkage and cracking be reduced with our modern materials and testing techniques? Can
distances between construction joints be extended to save construction cost and make the structure more
sustainable by resulting in less joints that will need maintenance.
Need and Benefit
Concrete is typically jointed to force cracks to occur at particular locations. Random cracks occur to alleviated
internal strains that are greater than the materials tensile strength. These cracks are unpredictable and often end
up needing repair or maintenance during the life of a structure. Internal strain can be generated by restraint,
temperature, chemical shrinkage, and/or drying shrinkage. Joint spacing is generally selected using rules of
thumb which were primarily based on older cement chemistry's. During construction, requests are often made to
extending the distances between joints and/or eliminating joints to increase the speed of construction and save
in scheduling costs.
Although many products and techniques claim to have an effect on concrete cracking, there is very little
consistency in the testing and very little data available to compare the crack resistance of a concrete material.
Previous studies by the Bureau of Reclamation have looked at specific concrete materials for repair type
applications. Another study looked at chemical shrinkage (using one test) to evaluate one type of concrete
A more comprehensive program to look at a number of products and/or techniques and compare them using the
same suite of laboratory and field tests is needed to be able to quantify the properties that can be achieved with
today's cementitious components and to allow Reclamation the tools to specify appropriate and relevant
properties when designing large concrete structures.
This work will complement research currently underway at USACE/ERDC and the joint conclusions could be a
benefit for both agencies.
Contact the Principal Investigator for information about partners.
Bureau of Reclamation Review
The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.
Comparative Analysis on Reducing Concrete Shrinkage and Cracking (final, PDF,
By Katie Bartojay, Catherine Lucero
Research Product completed on September 30, 2018