OasisLMS

This course will cover various aspects of D-cracking of concrete pavement: pavement cracking near contraction and construction joints that follows the joints. D-cracking in concrete pavement is a contentious and far-reaching issue that usually results in earlier-than-expected deterioration of concrete pavements. D-cracking is a result of critically saturated concrete exposed to frequent freezing-and-thawing cycles and, combined with frequent traffic, causes spalling and opening of concrete pavement joints over time.This course contains two presentations. The first presentation details a study of a severe D-cracking case in which a pavement slab was critically saturated and exposed to freezing, thawing, and heavy wheel traffic. The presented D-cracking studies include photo-elapsed images, petrographic examinations, and reasons why the D-cracking occurred; the presenter also discusses the failure of preliminary patching repairs. The second presentation discusses D-cracking as an issue with the quality of aggregates in concrete pavement mixtures and identifies certain properties of aggregates that make them susceptible to D-cracking based on previous known experience. Three tests are presented to help identify and prequalify the quality of aggregates that should be used in pavements to reduce D-cracking.

The contents of this course include two recorded presentations from the ACI 2015 Spring Convention:
• Examining the Role of Moisture in D-Cracking of Concrete Pavement by Thomas L. Rewerts, Thos. Rewerts & Co. LLC
• Iowa’s Approach to Reducing the Risk of D-Cracking by Peter C.Taylor, CP Tech Center

1. Describe current industry thinking on the causes of D-cracking in concrete pavements.
2. Understand field and petrographic investigation methods that help concrete professionals to evaluate D-cracking problems.
3. Describe test methods used by the Iowa Department of Transportation to qualify coarse aggregates that have been proven in minimizing D-cracking.
4. Explain the role that moisture retained in pavement joints and slabs and critical saturation play in the formation of D-cracking in concrete pavements.

Study the materials included in this module. Then, complete and pass the corresponding 10-question quiz with a score of 80% or higher to receive a certificate for 0.1 CEU (1.0 PDH).
Continuing Education Credit: 0.1 CEU (1.0 PDH)
Approved by AIA
Access Period: 30 days