Structural Portal

RepairUndergroundStructuralSilica Fume in Shotcrete

John Wolsiefer, Sr., and Dudley R. Morgan

Silica fume is a highly pozzolanic mineral admixture that has been used mainly to improve concrete durability and strength and as portland cement replacement. Silica fume has been used primarily in the United States, Canada, and the Scandinavian countries, but is now finding increasing use

UndergroundStructuralSteep Slope Stabilization with Fiber-Reinforced Shotcrete

Michael Ballou

For the past 150 years or so, roads have been built through the mountain passes in the western U.S. and Canada. Sometimes these roads led to mines; sometimes they started as logging roads. Some were built for access roads for the railroad. Many were built

UndergroundStructuralSpecification of Shotcrete Toughness

Roland Heere and Dudley R. (Rusty) Morgan

Fiber-reinforced shotcrete has become an established material for ground support in tunnelling and mining applications as well as in new construction and infrastructure repair. Designers and specifiers frequently require such shotcrete to maintain some quantifiable postcrack strength or toughness. Until the newly published round panel

RepairStructuralShotcrete Repair Saves Baltimore Bridges

I. Leon Glassgold

This Shotcrete Classic was selected for reader interest. While first published 23 years ago, most of the dry-mix shotcrete technology described for repair of bridges still remains relevant today. There are a few areas where things have changed. Small line wet-mix shotcrete equipment is now

RepairStructuralArchitectural Finishes for Retaining Walls

Marcus H. von der Hofen

What kind of architectural finishes are possible with shotcrete? From the most basic natural gun finish to exotic carved sculptures, from the gray color of regular portland cement concrete to custom-colored and stained mixtures, shotcrete can take on many different types of finished appearance. Today™s

RepairStructuralJefferson Street Bridge: The “Million Dollar Bridge” Listed on the National Register of Historic Places

Bill Fortuna

Dubbed the “million dollar bridge” by town residents, referring to the cost of building the structure in 1921, the Jefferson Street Bridge in Fairmount, WV, is a three-span reinforced concrete arch bridge that crosses the Monongahela River. Listed on the National Register of Historic Places,

UndergroundStructuralShotcrete for Ground Support: Current Practices in Western Canada

Cesar Chan, Roland Here, and Dudley R. Morgan

Historically, in Western Canada, the stabilization of rock slopes and construction of excavations have been achieved using methods such as soldier piles and lagging or construction of cast-in-place concrete retaining walls. In the case of reinforced cast-in-place concrete, there is a requirement for erection of

RepairStructuralUnderground Parking Garage Rehabilitation Using Dry-Mix Shotcrete

Randle Emmrich

RepairStructuralDeterioration and Rehabilitation of Berth Faces in Tidal Zones at the Port of Saint John

Paul Gilbride, Dudley R. Morgan, and Theodore W. Bremner

The Department of Justice (DOJ) Headquarters, 951 Constitution Ave. N.W., Washington, DC, has been undergoing major rehabilitation and renovation. Work started in 2001 and continued into 2002. Gilbane Building Co. is the prime contractor on the site, but there are many subcontractors involved in restoring

RepairStructuralTieton Dam Spillway Rehabilitation

Larry Totten

Johnson Western Gunite Company rose to the challenge of rehabilitating the Tieton Dam Spillway in Yakima, WA. The spillway, built originally in 1924, was showing significant deter-ioration due to freezing and thawing, weathering, and erosion due to high-velocity water flow. The owner, the United States