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Sponsored by ASCE's Transportation & Development Institute and ASCE Continuing Education.

INSTRUCTOR:  Mostafa A Elseifi, Ph.D., P.E., M.ASCE    

Course Length:  1 hour

Purpose and Background

Reflection cracking is a serious challenge associated with pavement rehabilitation.  Repairing a deteriorated road using a conventional overlay is rarely a lasting solution. The original cracks and joints that move due to thermal and traffic loadings propagate to the new surface, causing reflection cracking.  Different crack control methods, including the use of interlayer systems, have been suggested. The general belief among pavement engineers is that, even when a technique to delay reflection cracking is successful, the cost is equivalent to the cost of repairing the cracks. This opinion appears inaccurate when considering the appearance of the reflection cracking a few months after application of the overlay, which is sometimes the case.

Since the early 1930s, considerable resources and efforts have been spent on finding new and relatively inexpensive techniques to delay reflection cracking. Experimental investigations in the early 1980s showed that interlayer systems might be used to delay or to prevent the reflection of cracks through a new overlay placed over an old cracked pavement. Later, Button and Lytton (1987) postulated that the use of interlayer systems to mitigate reflection cracking can be achieved by using two different mechanisms: reinforcing HMA with a stiff interlayer to provide a better distribution of the applied load over a larger area and to compensate for the lack of tensile strength of the HMA and dissipating strain energy in the vicinity of cracks through the use of a soft layer.

This webinar presents a practical and comprehensive overview of different treatment methods and crack-control strategies with a focus on bituminous-based interlayer systems (e.g., stress-absorbing membrane interlayer, Novachip, etc.), saw and seal, and fractured slab approaches. Fractured slab approaches include crack and seat, break and seat, and rubblization. This webinar provides a review of bituminous interlayer systems, saw and seal, and fractured slab approaches as well as the cost-effectiveness of these strategies. The optimal conditions for each of these strategies will be presented and discussed.

How to Earn your CEUs/PDHs and Receive Your Certificate of Completion

To receive your certificate of completion, you will need to complete a short on-line post-test and receive a passing score of 70% or higher within 1 year of purchasing the course.

How do I convert CEUs to PDHs?

1.0 CEU = 10 PDHs [Example: 0.1 CEU = 1 PDH]