Internal Curing

The Wilson Dam bridge deck, part of the iconic 100-year-old hydroelectric dam on the Tennessee River in Muscle Shoals, Alabama, is ready handle another century of traffic. Arcosa Lightweight’s material played a pivotal role in these extensive repairs, ensuring the bridge’s longevity by supporting the Tennessee Valley Authority’s (TVA) first-ever use of internally cured concrete.

Faced with the challenge of maintaining aging infrastructure while optimizing taxpayer dollars, state Departments of Transportation are turning to innovations like internally cured concrete to improve bridge deck durability. Worn surfaces not only inconvenience drivers but also lead to frequent, costly repairs. By integrating advanced materials and data-driven decision-making, DOTs are extending the lifespan of critical infrastructure, reducing environmental impact, and improving safety for the public.

Internal curing is being recognized as a significant advancement in concrete technology. Today, the integration of lightweight aggregate (LWA) into concrete offers enhanced performance by reducing cracking, improving durability, and extending the service life of critical infrastructure. From bridge decks to highway pavements, this innovative technique is delivering longer-lasting solutions with lower maintenance costs.

When the Louisiana Department of Transportation & Development (LADOTD) planned to build a bridge on U.S. 80 over the Kansas City Southern railroad, they chose to incorporate internally cured concrete (ICC) to improve durability and performance. As an early successful test project, this effort demonstrated ICC’s potential to significantly enhance the lifespan of bridge decks.

From an engineering perspective, Mitch Wyble, P.E., City Engineer at Lafayette Consolidated Government, really likes what he sees when he discusses the value of internally cured concrete (ICC), a concrete mixture where a portion of the fine aggregate is replaced with similarly sized prewetted lightweight aggregate (LWA). Wyble first encountered ICC years ago while serving on the Technical Committee of the Concrete and Aggregates Association of Louisiana (CAAL).

Since 2016, the Kansas Department of Transportation (KDOT), along with the University of Kansas (KU) and the State of Minnesota, has been studying the use of internal curing to improve bridge deck service life. Traditional concrete bridge decks, with their high cementitious materials content and low water-to-cement ratio, are prone to early age cracking and self-desiccation.

The Union Pacific Dallas Intermodal Terminal (DIT) project stands as a testament to the transformative benefits of lightweight aggregate in improving the durability, strength, and overall performance of concrete paving. Notably, it remains one of the largest internal curing paving projects in the United States, with over 250,000 cubic yards of concrete used.

Denver Water is committed to ensuring safe and reliable water for its customers. To achieve this, the utility continually upgrades its system by replacing aging, large-capacity water storage tanks with more durable designs that are less susceptible to leaks. One way they have done that is through the use of Internally Cured Concrete (ICC).