Transportation agencies strive to provide durable, long lasting concrete bridge decks. While high performance concrete is frequently desired due to its resistance to chloride ingress and corrosion, these mixtures are often accompanied with an increased risk of early age cracking due to the use of high cementitious contents, low water-to cement ratios, and finer particle sizes. In fact it is often said that the high performance concrete produced is durable, but only between the cracks. Internal curing is one method that has been developed to design concrete to be less prone to early-age cracking. Internal curing also reduces the rate of chloride (or fluid) ingress which can lead to corrosion. The fluid transport properties are reduced in three ways. First, internal curing supplies additional water that promotes increased hydration thereby reducing the porosity of the concrete. Second, internal curing reduces influence of the interfacial transition zone causing it to be almost nonexistent at the LWA when compared with the interfacial transition zone around sand. Third, internal curing reduces unwanted cracking thereby reducing other paths for fluids to reach the reinforcing steel.
Citation: Concrete Bridge Views
Pub Type: Others
Concrete, cracking, diffusion, hydration, internal curing.