January 1997 Table of Contents

Features Working Round-the-Clock

When nasty weather results in the loss of 29 work days on a large, fast-track project, a contractor has to pull out all the stops to get the job back on track. That was the situation faced in January 1996 by The Clark Construction Group Inc. during construction of a 748,000-square-foot computer-chip manufacturing facility for Dominion Semiconductor, a Manassas, Va.-based joint venture of IBM and Toshiba. The complex's main fabrication plant is constructed primarily of cast-in-place concrete. The challenging concrete work included multiple floor levels, walls, columns, and sections of waffle slab. But in addition to the complexity of the job, Clark had to contend with the area's worst winter on record in nearly 100 years and one of its wettest springs. Read more

Features Flexible Forms Create Both Curved and Straight Walls

To complete construction of a 188-foot-long, 124-foot-wide oval oxidation ditch for a large wastewater treatment plant on schedule, general contractor Peterson Construction Co. saved time and labor by using a flexible forming system that could accommodate both straight and curved walls. The structure's four concentric, 14-foot-high, 1-foot-thick concrete channel walls required the forming of 64-foot-long straight sections as well as curves of four different inside radii: 8, 23, 42, and 61 feet. Read more

Features The Musts of Successful Cold Weather Concreting

Before you take a job in the fall or winter, you need to examine how you'll deal with problems like frozen subgrades, extended concrete setting times, slower strength gain rates, and decreased worker comfort (and efficiency). To obtain high quality concrete under these conditions, it's important to take the five general precautions listed below. Read more

Features Placing Crew Safety

Pumping booms move concrete quickly and efficiently for placements such as high-rise decks, base mats, walls, and bridge decks. But placing crews working in the area beneath the boom must take special precautions to ensure safe pump placements. Rules each crew member should follow include wearing the proper protective gear, watching the boom as it's moving, attaching a safety cable or chain to the discharge hose, and never trying to kink the discharge hose to stop concrete flow. Read more

Features Megatrends Affecting the Construction Industry

Construction management consultant FMI Corp. documents the underlying forces that will impact the direction and profitability of the industry in the last half of the 1990s and the early 21st century. Many of these factors have already become major influences, and others have only recently surfaced. Factors that could have the greatest impact on concrete contractors include: Read more

Features Concrete Plays Key Role in Chicago's McCormick Place Expansion

Completed in December 1996, the $670 million South Building expansion of Chicago's McCormick Place Convention center was one of the largest develop/design/build projects in the United States. Despite the vast scope of the 2.9-million-gross-square-foot expansion, Mc3D Inc., the develop/design/build consortium assembled specifically for this project, completed the work on schedule and under budget. One of Mc3D's biggest challenges in expanding the convention center was the diversity of the concrete work: More than 200,000 cubic yards of cast-in-place concrete were required for road construction, building construction, and architectural elements. Read more

Features OSHA Focuses on New Inspection Initiative

To help reduce jobsite injuries, illnesses, and fatalities, the Occupational Safety and Health Administration (OSHA) has initiated a focused inspection policy for construction sites, enabling inspectors to zero in on the top safety hazards. Under the plan, implemented by OSHA in January 1995, the typical top-to-bottom OSHA inspection is replaced on qualified projects (those with adequate safety and health programs) by shorter inspections that concentrate on the four leading causes of construction-site fatalities and injuries. The plan is based on a five-year study of accidents that caused most of the fatalities and injuries in construction. Read more

Features Single-Sided Moving Wall Form Eliminates Ties

Can you build a 30-foot-high wall with a form that's only 15 inches high? Partners Jim Grantham and Leroy Gray, of The Gray+Tham Co., Seattle, have developed and patented a method for doing just that. Workers can raise the forms a few inches at a time as permitted by stiffening of the concrete, so lateral pressures never have a chance to build up and form ties are not required. Since the forms can be erected and stripped manually, no crane is needed. Read more

Features Document Your Job on Computer

When problems occur on a jobsite, causing costly delays, it's important to clearly document them in case you later have to prove a claim for damages in court or arbitration. Windows-based software developed by TRF Systems Inc. makes this type of documentation possible by allowing you to take jobsite photos with a digital camera and automatically download them into a personal computer. The software dates and time-stamps the images and archives them in a secure database. Read more

Features RCC: An Rx for Rehabilitating Embankment Dams

Many dams, especially earthen embankment dams constructed prior to 1960, do not meet today's higher hydraulic design criteria. Hydrologically deficient, these earthen dams were simply not designed to safely store or pass at least one-half the calculated probable maximum flood. As engineers search for cost-effective ways to rehabilitate deficient embankment dams, more and more of them are discovering the value of roller-compacted concrete (RCC) overlays. Read more

Features Incentives and Results Make Safety Programs Work

When Rocky Geans, a residential concrete contractor in Kishawaka, Ind., first started a safety program for his workers in 1991, it was an uphill battle. Today, the 20 employees of L.L. Geans & Sons Inc. have a different attitude about safety: It results in peace of mind. Read more

Problem Clinic Cracking Caused By Cardboard Void Forms?

Last summer we poured a structural slab on grade over 4-inch-high cardboard void forms and a cardboard cover sheet. As shown on the detail, the slab is either 4 or 5 inches thick with #3 reinforcing bars at 16 inches on center in the 4-inch-thick slab sec Read more

Problem Clinic Can Footprints in Concrete Be Removed?

While applying curing compound, one of my workers walked on a parking structure deck too soon. He left footprints in the concrete that are very shallow, less than 1/16 inch deep, but still visible. There are many of these footprints in areas of up to 900 Read more

Problem Clinic Source for Inflatable Forms

We have a potential application for an inflatable form shaped like an 18-inch-thick pancake about 12 or 13 feet in diameter. However, we can't find a source for inflatable forms. Can you help? Read more

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