September 1985 Table of Contents

Features Special Procedures for Working with Flowing Concrete

When used to produce flowing concrete, a superplasticizer can make placing and consolidating concrete much easier. Here are some of the guidelines the U.S. Corps of Engineers developed for placing flowing concrete. Read more

Features A Proposed Test to Determine the Cracking Potential Due to Drying Shrinkage of Concrete

The control of cracking is a problem that concerns those who design and build with concrete. But there hasn't been any standard test that evaluates quantitatively what the effect is on drying shrinkage cracking in the field when one material or condition is changed. Now a test is being developed that has been introduced for consideration by the American Society for Testing and Materials. Read more

Features Waterblasting Robot Helps Complete Bridge Repair 14 Months Early

The $4.6 million contract to rehabilitate a bridge on Interstate 190 near Grand Island, New York allowed 18 months for construction. Based on a visual inspection of the bridge, the contract called for the removal of 14,000 square feet of bridge deck. Deteriorated surface concrete was to be removed to a depth of at least 1 inch below the top reinforcing steel. Read more

Features Floors Out of Tolerance Ground Flat

In 1983, after it stood vacant and incomplete for seven years, funding finally became available again to finish construction on a 5-story, southern California medical center. The foundation, walls and floors had already been completed, but the 7-year-old floors, made of lightweight concrete over metal decking, were badly out of tolerance. Read more

Features Solidification of Hazardous Wastes Using Portland Cement

The use of cementitious materials for solidifying hazardous substances has recently shown considerable promise. The advantages of solidification, sometimes called stabilization, include: safer transportation and easier burial; less pollution of the environment caused by leaching and evaporating of hazardous constituents; improved physical properties of the wastes for easier handling; potential for recycling wastes into construction material; detoxification of substances for protection of workers. Read more

Features Bits and Blades: What Makes Them Cut Faster and Last Longer

To select blades or bits for cutting concrete, a contractor doesn't need to know how they are made, but he should know how they will be used--the type of concrete he has to cut and the machine he plans to cut with. A manufacturer of concrete cutting equipment can then recommend a blade or bit that will match the concrete and the machine. Read more

Features Concrete Saws and Drills: What Can They Do? When Are They Useful?

What kinds of cuts are concrete saws and drills capable of making? The possibilities seem limitless. Saws and drills can be used to cut openings in walls and floors for doors and windows, for pipes, conduit and air ducts, and for staircases, elevators and trash chutes. They can also be used to cut buildings or bridges into pieces for safe dismantling. Read more

Problem Clinic Finish for Overhang on Earth-Sheltered House

The bottom surface of the overhang on an earth-sheltered house we've built is unattractive in appearance and we must provide some kind of pleasing finish. Either rubbing or machine finishing would be very difficult to do overhead. Sandblasting wouldn't be Read more

Close X