April 1979 Table of Contents

Some important considerations for Quality Finishing of Concrete

The quality and serviceability of a concrete floor or slab depend both on the materials in the concrete and on the quality of the work done in placing, finishing and curing. Read more

This Is How to Finish Flatwork

Skill in handling tools comes only with practice, but it is important to develop the right techniques and understand the importance of timing. Read more

Finishing Plain and Heavy-Duty Surfaces

After the initial operations of spreading, screeding and darbying, concrete should be allowed time to begin its setting process. Read more

Ornamental Finishes

Special finishes can add interest in situations where people are at leisure to enjoy their surroundings. Read more

Curing Flatwork

Although curing of concrete flatwork is not an integral part of placing and finishing operations, it is still indispensable in producing an acceptable finished product. Read more

Finishing Problems and Surface Defects in Flatwork

The contractor or cement mason who wants to be in full command of most job situations should be able to identify and dispose of the potential difficulties. Read more

Problem Clinic Superplasticizers and Strength

As I understand it when a superplasticizer is added to a truck mixer at the jobsite, the slump immediately increases substantially and, for at least a short time, the concrete becomes very fluid and easy to place. Does this make the 28-day strength any higher or lower than it would otherwise have been? Read more

Problem Clinic Superplasticizers and Segregation

What is the good of making a mix more fluid by adding a superplasticizer? I realize that the superplasticizing doesn't harm the strength by increasing the water-cement ratio, but what about increasing segregation? I think of a mix that flows as a mix that Read more

Problem Clinic Cracks From Backfilling

What causes cracks near the ends of basement walls? These cracks start at the top, about a foot from each end, and run down at an angle all the way to the bottom. I say this happened in backfilling, because there is also a vertical crack at the center of the wall. This crack is wider on the inside face of the wall, but the others are wider on the outside. Read more

Problem Clinic Joint Movement and Spalling From Lift-Truck Traffic

We have had more than one complaint about vertical movements in keyed joints when heavy lift trucks run over them. In some cases this has been enough to cause spalling. We have used premolded tongue and groove strips to form these joints. Would dowels solve this problem? Read more

Problem Clinic Shotcreting in the Wind

Is there any admixture that will keep cement and sand from being blown out of the jet stream of nozzle-mixed shotcrete when work is being done in windy weather? Read more

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