August 1998 Table of Contents

Features Mechanical vs. Lap Splicing

Lapping of reinforcing bars has long been considered an effective, economical splicing method. But today's more demanding concrete designs are forcing builders to consider alternatives. One such alternative is butt splicing using a mechanical connection, which consists of a sleeve to align bars and hold them in position. For tension connections and some compression connections, the sleeve transfers the tension or compression force directly from one bar to another. The connection of sleeve to bar is made by threading, swaging or filling the annular space between the bar and the sleeve with a molten metal. Read more

Features Keep on Truckin'

Today's pickup trucks offer a wide variety of options that can be customized to fit your needs. But there are a few things you should know before you go to the dealership. Read more

Features Heavy-Duty Form Panels Handle the Pressure

When work started last summer on the seven-story, $35-million expansion of the Sandestin Beach Hilton Hotel, Destin, Fla., contractor Roy Anderson Co., Gulfport, Miss., was faced with the task of adding 200 rooms and 60,000 square feet of commercial and meeting space. Clearly, the job would be formwork-intensive, requiring many different wall lengths, several elevator shafts and a multitude of pilasters. Read more

Features Making the Jump to Commercial Construction

Concrete contractors make scores of decisions every day, but if you're a residential contractor, perhaps the most pivotal decision you'll ever make is whether to expand into commercial construction. The transition can be intimidating, especially if you're not prepared. Suddenly you are faced with spec books, architects and engineers, liquidated damages, bonding requirements, and regulations around every bend. Read more

Features Selecting a Wet-Mix Shotcrete Pump

Contractors aware of the versatility of shotcrete might not be aware of the wide selection of concrete pumps available for repair with wet-mix shotcrete. This roundup focuses on swing-tube pumps, which can handle concrete with ¾-minus aggregate as well as wet-mix shotcrete, which may contain smaller aggregates. Most models have watertight valves to keep the mix liquid. Read more

Features Are Your Slabs Dry Enough for Floor Coverings?

In the United States, most floor covering manufacturers require concrete floors to reach a water-vapor emission rate of either 5 or 3 pounds/1,000 square feet/24 hours before workers can place the floor covering. Installers place the floor covering when the specified emission rate has been reached, as confirmed by a calcium chloride cup test. But research conducted by The Aberdeen Group shows that it's difficult to accurately estimate the drying time needed for concrete to reach a specified vapor-emission rate. Read more

Features Caring for a Laser Level

Laser levels must be handled with care to keep their electronic circuitry, electric motors and glass optics aligned and calibrated. But in the rough environment of a typical jobsite -- where dust and mud, rugged terrain, and harsh weather conditions prevail -- these sensitive electronic instruments really take a beating. Read more

Products Solving Problems Concrete Imitates Stone

A mason from Maine has built a concrete retaining wall that appears to be made of hand-laid stone around his home. Read more

Products Solving Problems New Tool for Grooving or Grinding Pavements

Pavement sawing contractor Rick Younger invented a patented device for grooving and grinding concrete pavement. It consists of replaceable straps mounted on a rotating drum with a metal inner core. Read more

Problem Clinic Scaling After 25 years

The broom-finished driveway of my house in North Carolina is 25 years old. I bought the house several years ago and have applied rock salt (sodium chloride) to the driveway during the winter to remove snow and ice. Read more

Problem Clinic What's a Hairline Crack?

I often hear the term "hairline crack." How wide and deep is such a crack? Read more

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