July 1993 Table of Contents

Features Breaking Up Is Easy to Do

Machine-mounted hydraulic impact hammers and concrete crushers both demolish concrete methodically and efficiently. Using them effectively and economically, however, requires knowing which type of demolition tool is best for the job, what size tool is needed, and how to properly match tool to excavator. Read more

Features Safe Demolition

Before beginning a demolition project, OSHA mandates that an engineering survey of the structure be undertaken by a competent person. The survey determines the condition of the framing, floors, and walls, and also the possibility of the unplanned collapse of any portion of the structure. Safe floor loads should be determined to prevent overloading with demolition debris. Read more

Features Hospital Benefits from Unique Crushing Method

Recently the Children's Hospital in Detroit experienced a unique construction occurrence - quiet demolition. This interesting method will have further applications for contractors working with tight restrictions on demolition. Read more

Features Recycling Concrete Pavements

Breaking up an old concrete pavement and reusing it as aggregate is a cost-effective option for reconstructing deteriorated pavements. Recycling eliminates disposal problems and tipping fees. In urban areas where landfill space is scarce, dumping concrete is difficult and costly. The cost of recycling concrete pavements only includes the cost of crushing. Costs for aggregate hauling and concrete disposal are eliminated. Read more

Features Engineered Demolition of Earthquake-Damaged Bridge Structures

Several major bridge structures and buildings in San Francisco were damaged during the 1989 Loma Prieta Earthquake. The review of some structures revealed damage that could not be repaired economically. Read more

Features Troubleshooting Tips from the Editors of Concrete Construction

SOLUTIONS FOR: Blistering, bugholes, crazing, curling, dusting, honeycombing, low test results, plastic shrinkage cracking, scaling, uncontrolled shrinkage cracking, uneven color, and wavy surface Read more

Problem Clinic Type I/II Cement

Bagged cement labelled "Type I/II" is being sold in our area. Is this a new type of cement in ASTM C 150? Read more

Problem Clinic Dowels or Keys in a 4-Inch Slab?

We are placing 4-inch-thick slabs. Can we use dowels or keyways for load transfer? Read more

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