Durability and bond of high-performance concrete and repaired Portland cement concrete.

摘要

The widespread use of deicing salts during winter maintenance operations has created many serious durability problems for transportation infrastructure. One of the major causes of repair failures is the deterioration of bond between old repaired pavement concrete and the new repair material with time under exposure to freeze-thaw cycling and salt application.; The most critical problem facing the highway industry and transportation authorities is how to invent and screen more durable, cost-effective and long-life repair materials. There are currently no ASTM Test Methods for evaluating the effects of deicing salts and freeze-thaw cycling on the durability of bonding between concrete materials. Two durability test techniques have been successfully developed in this study. These techniques combine bond evaluation and surface scaling resistance to deicing chemicals and/or freeze-thaw cycling to one test method. In addition, the developed tests can assess how moisture conditions of repaired concrete, surface preparation, curing length and conditions of repairs influence the bonding. Four most widely-used rapid setting repair materials were investigated by the developed test methods and the relative performances were compared. Proposed additional requirements for temporary and permanent repair materials to pavements and bridge decks are also presented.; The results of this study would provide considerable guidance in screening patching materials for transportation authorities.