Precast Magic: Creating Acreage Out of Thin Air

Illustrations courtesy of Woodall Rodgers Park Foundation; photos courtesy of Archer Western Contractors

By Sue McCraven

Precast concrete beams that are forming the foundation for a Dallas park in the air space above a busy downtown freeway may be structural “magic” but there’s nothing “presto” about the precision engineering involved in this $110 million undertaking. “This is a very meticulous project,” said Duane Milligan, TxDOT construction engineer. “It’s not easy to create ground, especially over a freeway.” Read More »

The Next Linn Cove

Like the Linn Cove Viaduct in North Carolina, on which it is partially modeled, the Foothills Parkway Bridge No. 2 in eastern Tennessee is being designed and built to protect the landscape it crosses.

By Deborah R. Huso

Work is continuing on the oldest uncompleted highway project in Tennessee this spring with the ongoing construction of the Foothills Parkway, a scenic, high-elevation drive near the northwest boundary of the Great Smoky Mountains National Park above Chilhowee Lake. Currently, just over 22 miles (35 km) of the Parkway are complete and open for travel. The byway provides breathtaking vistas both eastward into the Smokies and westward into the Tennessee foothills. Read More »

Abridged With Precast

Precast Bridge with UHPC Joints Shortens Vital Route for Tall Vehicles.

By Kirk Stelsel

When Henry Ford rolled the first Model T off his revolutionary assembly line in 1908, he forever changed the world. The Model T was the first affordable, mass-produced automobile and it ushered in a new era for transportation.

To imagine a world without motor vehicles today is almost unfathomable, but the automobile could never have made an impact without a proper network. Streets, highways, interstates and the focus of this issue, bridges, connect us and make vehicle transportation possible. Read More »

Precast Concrete Paving Slabs: Built to Last and Install Fast

By Adam Brodal, P.E.
Photos courtesy of Roman Stone Construction Co.

The U.S. Federal Highway Administration and AASHTO’s Technology and Implementation Group are championing precast concrete pavement systems (PCPSs) as part of their Highways for Life program. PCPSs fit well with the goals of the program, which are to promote construction methods that reduce traffic congestion, reduce project duration, increase safety and produce durable repairs.

About precast concrete pavement systems
PCPSs are long-term pavement repair treatments best suited to heavily trafficked areas that have a high cost for lane closures during construction. All PCPSs include methods for precast production, transportation and ensuring the panel is properly bedded to the subgrade. There are both jointed and unjointed slabs along with prestressed and non-prestressed systems. Read More »

Precast Concrete Home Building: A Building Market

Welcome to the first Possibilities in Precast column. Precast concrete is a versatile product, and its range of applications continues to grow. This new section will appear in future issues of Precast Solutions to keep you on top of emerging products and technologies within the precast industry.

By Kirk Stelsel

When it comes to residential construction, change often comes slowly. A number of factors, however, have led to new techniques and alternate building materials making headway into the market in recent years. In the 2000s, a series of hurricanes left Gulf Coast cities forever changed, a rapidly growing emphasis on sustainability emerged, and the recession refocused contractors and homeowners on cost savings and quality. Read More »

Inventory Control Comes of Age

RFID tag and barcode technology is becoming mainstream – and may soon be required by specifiers.

By Sue McCraven

Inventory control can be a big headache for precast concrete producers. Project delays mean stock and custom precast products pile up in the yard. For every piece produced and stored, precasters must accurately capture and record: product name; casting, shipping and delivery dates; and installation placement code. Pre-pour and post-pour inspections also must be recorded to comply with industry standards and NPCA plant certification. Read More »

How to Fix a Flooded Manhole

A precaster’s tried-and-true method for sealing a sump hole.

By Gary K. Munkelt, P.E.

Problem: A utility manhole is installed in an area with an unexpected high water table. The sump hole through the bottom slab allows a constant 2 ft (0.6 m) of water inside the manhole, preventing installation of equipment. How can the hole be sealed?

• Step #1: Drive pipe into ground. The pipe’s inner diameter must be larger than the outer diameter of the gel line.
• Step #2: Inject hydrophilic gel into the ground. Hardened gel will prevent movement of water; the gel hardens in soil when exposed to water. Read More »

Vacuum Testing Backfilled Manholes

By Claude Goguen, P.E., LEED AP

Whenever you have something inspected, there’s a natural tendency to want the inspection to occur at the latest stage of the process in order to measure performance in its final position. For example, wouldn’t you feel better having a plumber test a new water heater in your home once installed rather than test it while it’s still in the delivery truck?

Likewise, when a manhole is installed, it’s understandable when the owner, inspector or specifier wants a performance test once it is completely installed and in use. When it comes to vacuum testing, this presents an issue. Read More »