June 1983 Table of Contents

Features ACI 301 Specifications for Structural Concrete for Buildings

ACI 301 is a reference standard that the engineer or architect may make applicable to any building project by citing it in the project specifications, supplementing it as needed by designating or specifying individual project requirements. Read more

Features Slabs Built Without Vertical Shoring

One way to build without conventional vertical shores is to use long-span form panels supported by brackets or jacks attached to the bearing walls or columns of the building itself. Read more

Features Three Miles of Pavement Makes History in New York

For the first time in 30 years, a major street in Manhattan was paved in concrete rather than the more commonplace asphalt economy being a prime factor. Read more

Features Concrete Reinforced with Polypropylene Fibers

Used as secondary reinforcement, polypropylene fibers help reduce shrinkage and control cracking. Read more

Features History-Making Concrete Slab Demonstration at Manhattan, Kansas

Nearly 2,000 people watched a demonstration of concrete placing and finishing at Kansas State University's Weber Arena. The demonstration featured ten different concrete mixes and 21 test slabs, plus a variety of vibrating screeds and other finishing equipment. Read more

Features Are We Specifying Our Problems?

Too many times I have been called to look at some problem only to find that the specifications virtually guaranteed the poor result. Read more

Features LNG Storage Tanks: Concrete in an Ultra-Cold Environment

Safe transportation and storage of liquefied natural gas (LNG) require that the materials used to contain the fluid must withstand sub-arctic temperatures as low as -265 degrees F, the temperature to which the gas must be cooled in order to become liquefied. Read more

Problem Clinic Worries About Calcium Aluminate Conversion

Because it resists corrosion, calcium aluminate cement has been suggested for use in floors in a food processing plant. Some of these floors are above grade. Isn't it true that calcium aluminate loses strength drastically as it gets older? If so, it doesn't seem to be a good choice for a suspended floor. Read more

Problem Clinic Thin Shell House

I am seeking information on reinforced concrete construction for a thin-shell one-story house, complete section dome type. It will be curved around a court and have windows facing south for passive solar. The other sides are to be earth berm including som Read more

Problem Clinic Bridge Bearings

What do you think of elastomeric bridge pads, used to allow movement of prestressed concrete girders upon their supports? Do they really deform enough to allow the needed movement and do they last as long as machined steel bearing surfaces lubricated with Read more

Problem Clinic Fire Rating

The city is giving us trouble about an 8-inch-thick, cast-in-place reinforced concrete wall we want to build. They say we have to show them a fire rating for such a wall from an established agency, though they say they are ready to accept an 8-inch concre Read more

Problem Clinic A Little Rust on Rebars

In new construction should we remove the rust from rebars to be sure we get good bond to the concrete? Read more

Problem Clinic Peeling Coating

Stucco panels on one of our structures were treated with a silicone water repellent, flooded onto the surface by brush. Then an asbestos-containing coating was applied. After about 2 years the coating started peeling off in large pieces from about 6 squar Read more

Problem Clinic How Soon to Add Superplasticizer to High Strength Concrete

When using high range water reducers in 3000-psi or 4000-psi concrete we ordinarily introduce the admixture at the plant instead of at the jobsite, though many experts advocate adding it at the site. Does anyone add high range water reducers at the plant Read more

Problem Clinic How To Finish Flatwork

Where can we get a good manual on concrete finishing? Read more

Problem Clinic Vacuum Dewatered Vertical Surface Resists Heat

Can a concrete wall be made more resistant to intense heat by vacuum dewatering? Read more

Problem Clinic Testing Small Cylinders for High Strength

We will be using some high strength concrete and it has been suggested that we make 4x8-inch test cylinders because the capacity of the testing machine is only 250,000 pounds. Read more

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