Charged with maintaining critical infrastructure while conserving taxpayer dollars, state Departments of Transportation are on the lookout for ways to improve the performance of roads and bridges. Deteriorated pavements irritate drivers and damage vehicles, while the need for frequent repairs wastes both time and money.
It's been a decade since one of the largest internal curing paving projects in the United States kicked off with the placement of over 250,000 cubic yards of concrete paving. Dubbed the Union Pacific Dallas Intermodal Terminal (DIT), this unique project remains an excellent testament of lightweight aggregate's ability to improve the durability, strength, and quality of concrete paving.
Denver Water Department’s three successful water tank projects drive an ongoing demand for internally cured concrete across multiple districts.
From an engineering perspective, Mitch Wyble really likes what he sees when he assesses the value of internally cured concrete (ICC), a concrete mixture where a portion of the fine aggregate is replaced with similar sized prewetted lightweight aggregate (LWA). Wyble first encountered ICC a few years ago while serving on the Technical Committee of the Concrete and Aggregates Association of Louisiana (CAAL).
Internal curing has clearly demonstrated its beneficial effects on the performance of concrete bridge decks. The addition of pre-wetted lightweight aggregates to concrete mixtures can help reduce shrinkage stresses by reducing moisture differentials through the depth of a slab.
Constructing large capacity water storage tank slabs without construction joints is a complex proposition in Colorado's low humidity and often windy climate. One solution that has been successful is to specify low-shrinkage concrete mixtures and monolithic placement of the slab within a prescribed time period to reduce the probability of shrinkage cracking.
When the Louisiana Department of Transportation & Development (LADOTD) needed to construct a bridge on U.S. 80 over the Kansas City Southern railroad tracks to accommodate two lanes of northbound and southbound traffic, it decided to incorporate internally cured concrete (ICC) into its completion plan.
A 1,440 foot-long floating concrete breakwater was constructed in the state of Washington using lightweight aggregate produced at Boulder, Colorado. The $8 million breakwater project was designed for the Port of Bremerton Marina to attenuate wind driven waves and ferry wakes. Additionally, it was designed to upgrade the marina’s boat capacity, and enlarge the waterfront public space extending from an upland public park area.