Indianapolis' Clarian Health Automated People Mover became a project on the fast track. To ensure that construction of the 1.5-mile dual-track superstructure and guideway foundations — comprising the nation's first privately owned transit system to operate over city streets — proceeded with speed and efficiency, design-build contractor Schwager Davis, Inc. turned to Rinker Materials-American Precast at the earliest planning stages. The challenge presented was to quickly produce and turn high-quality concrete elements with strict finish standards, high strength and durability.

Recognizing the innovative nature of the project, Rinker put together a novel solution. Working with Grace Construction Products' Self Consolidating Concrete System, Rinker developed a concrete mix suited to the specific combination of forms and pieces required for the project. Forms included curved girders with 12-in.-wide cross sections, for example, and rebar configurations often left very little room for getting concrete down into the form.

The SCC mix virtually eliminated bugholes that can mar the appearance of precast concrete and require time-consuming patchwork. The mix reduced the need for labor-intensive vibration to distribute the concrete inside the forms. In addition to dramatically reducing labor while enhancing appearance, the SCC solution provided early strength so forms could be turned more quickly.

The key to the mix was Grace ADVA Cast 530. A superplasticizer designed for high early strength and high workability without segregation, 530 is optimized for SCC in precast and prestressed applications. A one-component product, it also made the mixing process easier to control for Rinker, eliminating the need for separate tanks and meters. To control set time, a Daratard 17 agent was added to the mix; Darex II AEA, an air-entraining admixture, was introduced for protection against damaging freeze/thaw cycles.

For the Clarian Health Automated People Mover, the end result was a structurally sound, cost-effective track guideway, providing quality appearance as well as strength and durability. And most importantly, the project — like any good train — ran right on schedule.
— Grace Construction Products, 877/423-6491 or www.graceconstruction.com

CLARIAN HEALTH AUTOMATED PEOPLE MOVER
AT A GLANCE

Contractor
Schwager-Davis, Inc.
Indianapolis

Precast Producer
Rinker Materials — American
Precast, Indianapolis

Admixture Supplier
W.R. Grace & Co.-Conn.
Cambridge, Mass.