August 1977 Table of Contents

Problem Clinic Superplasticizers for Easy Consolidation

The Problem Clinic item on page 232 of the April 1977 issue says that Portland Cement Association made a mix with 11.4-percent air content and a slump of 8.5 inches to get the mix to flow easily into forms and make it easy to consolidate. Couldn't we do t Read more

Problem Clinic Laitance Removal

Removing the laitance at the top of placements in a small dam is consuming an excessive amount of time. We sandblast the surface, but a considerable amount of concrete gets abraded off. Then we have a layer of both sand and concrete particles that have to Read more

Problem Clinic Roll-A-Bugs and Popouts

What is the probability of popouts due to stresses incurred by freezing and thawing in a slab of regular-aggregate concrete that has been roll-abugged prior to bull floating as compared with a slab of crushed stone or white rock concrete? Read more

Problem Clinic Safeguarding Alignment of Post-Tensioning Tendons

There is some chance that some post-tensioning tendons in a slab are misaligned. Could this be due to the impact of the concrete at the time it is placed? Read more

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