Development of Optimal Concrete Sealant Techniques Primary Researchers: Robert L. Mullen Department of Civil Engineering Case Western Reserve University, Cleveland, OH 44106, USA E-mail: rlm@po.cwru.edu, Tel. (216) 368-2423 Philip Perdikaris Department of Civil Engineering Case Western Reserve University, Cleveland, OH 44106, USA   Ohio Department of Transportation  award information   Abstract:        Though concrete coatings and sealants have been known to prolong the service life of concrete highway structures for some time, ignorance of the effect that moisture encapsulation has on the performance of such surface treatments persists. This study investigates the phenomenon of  moisture encapsulation and how concrete sealants and coatings      influence concrete freeze/thaw durability and moisture migration.  In this project several commercially available concrete coatings are applied to concrete cylinders of two sizes. The parameters of the study include curing duration and environment for the concrete, air drying time before coating and coated surface area.    Based on freeze/thaw durability tests (I 5 0 cycles) in air of a group of  specimens cast with class C structural concrete (4,000 psi or 27.6  MPa) it is concluded that encapsulation of moisture does not contribute to freeze/thaw degradation of the sealant.       Subsequent freeze/thaw cycling of another group of cylinders of lower  compressive strength in water demonstrates that coatings do reduce damage due to weathering. Also, it is concluded that no benefits are obtained by leaving portions of the surface area uncoated to insure breathability of the concrete. Furthermore, the important parameter of  moisture concentration can be readily and reliably determined by measuring the relative humidity in concrete.       A Finite Element Method computer model based on linear diffusion theory is found to adequately predict the drying behavior of concrete treated with relatively impermeable coatings. Nevertheless, it is determined that the process of diffusion alone is insufficient to describe the movement of water in concrete.       A final group of specimens of Class "C" have completed there exposure testing. The dynamic modulus of all cylinders have been measured. In addition, selected cylinders have been sectioned and images of local  coating failures examined. Other specimens have been tested for  compressive strength. The results of this testing have been included in the final report which should be submitted to ODOT for review  completed by the end of June 1998.   Acknowledgment: The authors acknowledge support from the Ohio Department of Transportation. CWRU Department of Civil Engineering Main Menu | Sitemap | Department Activities | On-Campus Menu                     Communication Click to request a Graduate | Undergraduate Application Form. Click to get in touch with a Graduate | Undergraduate Student. Click to Schedule a Tour of the Department.