June 1993 Table of Contents

Features Concrete Cover

In most building construction, concrete effectively protects reinforcement from damage caused by environmental factors or exposure to fire. In severe environments found in some industrial plants, marine structures, bridge decks and parking structures, destructive effects of reinforcement corrosion have been a problem. With proper design, mix selection, and construction practices, reinforced concrete structures can perform well in corrosive environments. Concrete cover makes an important contribution to this performance. Read more

Features Keeping Concrete Cool In the Heat of Summer

The accelerating effects of hot weather not only cause concrete to lose workability and finishability faster, they also can reduce long-term strength. There are many simple and effective solutions for avoiding hot-weather concreting problems, such as breaking the job into smaller placements or using more vibrator operators and finishers. The key is to plan construction operations with hot weather in mind. This will help you avoid taking measures on the day of the pour that can make a bad situation worse, such as adding more water to the concrete mix. Read more

Features Moving On Up

Knowing the types of material hoists available and their operations can help you choose the hoist that is right for you. Read more

Features Silica-Fume Concrete Proves to Be an Economical Alternative

When Milwaukee's General Mitchell Airport Authority decided to build a 600,000-square-foot, 2,300-car parking structure, one of the bid requirements called for separate proposals for silica-fume concrete and a traffic membrane. In a bid submitted by Milwaukee contractor C.G. Schmidt Co., silica-fume concrete was less than half the cost of a traffic membrane and offered several advantages. Read more

Problem Clinic Steel Vibrator Head May Damage Epoxy-Coated Rebars

Will immersion-type vibrators damage epoxy-coated rebars? I've heard that they do. If so, how do you consolidate concrete that contains epoxy-coated bars? Read more

Problem Clinic Stains From Straw

We read your recent article on cleaning concrete (November 1992, page 791) thoroughly but failed to find any recommendations on the removal of straw stains from concrete. In the past year we've had several requests for help with yellowish brown stains cau Read more

Problem Clinic Field Testing for Cold-Weather Concrete

We build residential basements and tried to work later in the season this year, but were concerned about the concrete coming up to strength in cold weather. Is there a field test that we can use to measure in-place strength? Read more

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