NEW ORLEANS, LA  Lafarge North America is making essential contributions to building more durable cities with high-performance concrete containing NewCem slag cement and fly ash to achieve the high-strength, resiliency and sustainability goals of the new University Medical Center (UMC) of New Orleans, Louisiana.

Since Hurricanes Katrina and Rita, southeast Louisiana has worked diligently to create a stronger, more resilient built environment. Constructed to withstand a variety of natural disasters, the 2.3-million-square-foot UMC complex restores much-needed healthcare services to the local community and serves as a key center for academic training and research. The $1.1 billion state-of-the-art facility, which is designed to LEED Silver standards, is the only level-one trauma center in the region and serves as the hub of an expanding downtown medical district in New Orleans.

For the UMC New Orleans project, Lafarge provided high-performance concrete containing two different blended cement mix designs that incorporated NewCem slag cement and fly ash. Blended cements, which contain supplementary cementitious materials (SCMs), enhance the strength and durability of concrete, reduce concrete's permeability to water and aggressive chemicals, and contribute to LEED credits. The use of SCMs such as slag (a by-product of steel-making) and fly ash (a coal-combustion by-product) in concrete enables the reuse of industrial by-products that would otherwise be landfilled and reduces the amount of virgin material required for concrete.

Concrete exposed to sulfates is vulnerable to deterioration that usually takes the form of loss of adhesion and strength but may also be seen as expansion, cracking and spalling. Due to the severe (Class 3) sulfate-rich soil found at the project site, Lafarge's quality control team evaluated the sulfate resistance of various high-performance mix recipes over 18 months using ASTM test method C1012. Based on those studies, Lafarge recommended and supplied 34,000-cubic-yards of a high-performance concrete containing a 50-percent Portland Type I/II, 50-percent NewCem slag cement blend for the foundation slabs that would provide long-term durability, impart high sulfate resistance and achieve a compressive strength of 7,000 psi.

The resilient and eco-friendly design of the UMC complex also relied on 75,000-cubic-yards of high-performance concrete containing a 20-percent fly ash-80-percent Portland Type I/II blended cement mix that Lafarge produced and supplied for the beams, columns, elevated floors, and other structural applications.