April 1989 Table of Contents

Features RCC Paving Record Set

In a single pass, workers in upstate New York placed a 10-inch-thick roller compacted concrete (RCC) pavement. This job was the largest RCC pavement project ever done at the time. Read more

Features Safety and Maintenance Tips for Mini-Excavators

Whether you're a novice or a veteran equipment operator, reviewing safety tips and maintenance guidelines helps you operate your mini-excavator better. Before beginning work, check the work area for underground lines and cables, overhead power lines, hidden holes, obstacles, dropoffs, and steep slopes. Dress in close-fitting clothes with a safety helmet and non-skid shoes. Read more

Features Shotcrete Restores Fire Island Light

A crumbling structure on the south shore of Long Island has been restored in response to public demand, using state-of-the-art concrete technology. The historic Fire Island Lighthouse was built of brick in 1858. The original brick construction was covered with a protective portland cement wash in 1871 and again in 1876. Then in 1912 a reinforced concrete coating was applied. Read more

Features Retaining Wall System Offers Economy, Speed of Construction

TTW is a Maryland design-build firm that uses precast concrete panels to build retaining walls, bridge abutments, and walls for erosion prevention. Each wall consists of three parts: Read more

Features Whitetopped Parking Lot Report Card

Since being rediscovered in the late 1970s, whitetopping has become a standard method for rehabilitating deteriorated asphalt pavements. Read more

Features Mini-Excavators Help Excavating Contractors Fill Market Niche

Milwaukee excavating contractor Howard LePine uses mini-excavators, scaled down versions of the bigger machines used for mining and heavy construction. Read more

Features Downsized Motor Graders

Buying a compact motor grader makes sense. One man with this single piece of equipment can handle all of these site preparation tasks: initial ground breaking; rough grading; base compaction; fine grading; and cleanup of excess material. Read more

Features Take Time to Check Out Time Provisions in Contracts

One of the most important and least complied with contract provisions is time. Make sure there are adequate delay provisions in contracts for reasons beyond your control. Subcontractors should use the contract documents of The American Institute of Architects (AIA), or insist on a liquidated damages clause if an AIA contract is not used. Read more

Features Three 172-Foot-High Storage Silos Slipformed in 10 Days

Workers from two 12-hour shifts slipformed three 172-foot high reinforced concrete storage silos in 10 days in Baltimore, Maryland. Read more

Features Are Thickness Tolerances for Concrete Floors on Grade Realistic?

ACI 117, Standard Tolerances for Concrete Construction and Materials, gives tolerances for slabs up to 12 inches thick of +3/8 inch and -1/4 inch. For the past few years, I've been gathering data on thicknesses of concrete slabs, and I've found that most slabs don't conform to ACI 117. Read more

Problem Clinic Delayed Setting of Superplasticized Concrete

What causes delayed setting of superplasticized concrete? We placed a 2-foot-thick slab on grade for a water treatment plant. Maximum air temperature during the pour was 65 degrees F. We placed the concrete directly onto a polyethylene vapor barrier. At m Read more

Close X