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

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, the bridge was originally designed by The Steel Engineering Company of New York and was dedicated to the town of Fairmont on May 20, 1921. The John F. Casey Company of Pittsburgh completed the original construction.
Having been used by Fairmont residents for more than 70 years, the Jefferson Street Bridge needed restoration work to ensure the continued safety of the structure. The goal of the restoration project was to take down 80% of the structure with only the original arches remaining intact, reconstruct the bridge with new materials, and retain the same appearance as the original 1921 design.
In 1998, the Mosites Construction Company of Pittsburgh began the two-year restoration project. Working with architectural firm Howard Needles Tammen & Bergendoff (HNTB) of Alexandria, VA; engineering firm Gannett-Fleming of Pittsburgh; and RCS Consulting of Ripley, WV, Mosites Construction Company had to overcome numerous challenges related to the design and location of the bridge. Before any demolition could be done, precautions were taken to protect a communi-cations fiber optic cable that ran under the south sidewalk of the bridge. Also, to preserve the six original arches, special engineering methods were employed to keep the demolition of other areas of the bridge from harming the arches. To duplicate the original appearance of the structure parapet and light poles, special architectural precast forms were designed.
To help restore the piers and arches, Mosites Construction Company turned to The QUIKRETE® Companies for its high-quality commercial-grade products. Using 6400 m2 (69,000 ft2) of 37.5 mm (1.5 in) thick pneumatically applied QUIKRETE® Gunite MS®, Mosites successfully restored all four sides of the existing arches.

Shotcrete for Ground Support: Current Practices in Western Canada

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 formwork, fixing of reinforcement, pouring the concrete mixture, and vibration to ensure good concrete consolidation and steel encapsulation. These methods have proven to be relatively ineffi-cient and costly in many cases. In recent decades, however, the use of shotcrete for ground support has seen increased use, as shotcrete has allowed

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

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 the DOJ building. Coastal Gunite Construction Co.,

Tieton Dam Spillway Rehabilitation

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 Department of the Interior Bureau of Reclamation, designed a repair consisting of a 12-in.-thick (300 mm) reinforced, cast-in-place concrete overlay on the floor and left wall if one was looking downstream. The budget in the original contract was not sufficient to overlay the right wall.

Determination of Early-Age Compressive Strength of Shotcrete

Tere has long been a need for a reliable, simple-to-use means of determining the early-age rate of strength gain in shotcrete.During approximately the first 24 hours after shotcrete has been placed, its compressive strength is typically too low to measure using standard core-extraction and testing procedures. Monitoring the rate of early-strength development in shotcrete is important in tunneling, mining, and other applications such as the underpinning of structures. Recent studies by the authors have demonstrated that there is a simple, direct method for determining the early-age compressive strength development of shotcrete. It involves the shooting of a set of beams in a standard steel mold and testing the beams after stripping, using an adaptation of ASTM C 116, œStandard Test Method for Compressive Strength of Concrete using Portions of Beams Broken in Flexure. This œTechnical Tip describes a procedure for deter-mining the compressive strength of shotcrete beams and presents results of tests conducted with plain and accelerated shotcretes produced by both the wet- and dry-mix shotcrete processes.

Shotcrete Meets the Challenge of Huge Water Project in Ecuador

Shotcrete Meets the Challenge of Huge Water Project in Ecuador replacing traditional œform-and-pour reinforced concrete construction methods with high-production shotcrete, the massive Trasvases Manabi Water Project in Ecuador was finished months ahead of schedule. Contractor Norberto Odebrecht, in conjunction with Shotcrete Technologies, Inc., of Idaho Springs, Colorado; and Commercial Shotcrete, Inc., of Higley, Arizona, placed over 6000 m3 (7800 yd3) of shotcrete in less than half the time it would have taken by the specified œform-and-pour method. They put the project an entire rainy season (approximately four months) ahead of schedule.

Design Guidelines for the Use of FIber-Reinforced Shotcrete in Ground Support

Developments in Shotcrete in Hobart, Tasmania, Australia in April 2001. One of the outstanding papers presented at the Conference was a paper by Grant, Ratcliffe and Papworth on œDesign Guidelines for the use of SFRS in Ground Support. Frank Papworth was asked to submit an updated paper on the subject for publication in the ASA Shotcrete Magazine and so here it is. It is more technical than most of the papers published in the ASA Shotcrete Magazine, but was selected because it was considered that it would be of considerable value to designers of fiber-reinforced shotcrete linings for ground support in civil and mining applications.
Abstract: There are presently no design guide-lines based on toughness for the use of fiber-reinforced shotcrete (FRS) in ground support for underground mine development. Typically, in the Australian mining environment, the approach to the use of FRS has been one of borrowing experiences from other mines and a œtrial-and-error method of design, installation, and assessment. There is a need for a ground support design guide that can be simply applied by œfront-line personnel.
This paper provides an overview of the performance characteristics of FRS and how the various shotcrete guides specify its use. Practical experiences with the use of FRS in Australia and Canada in various applications and ground conditions are combined with existing empirically based ground support-design methods to develop a ground support guideline that incorporates the concept of toughness. An assessment of structural synthetic fibers shows that their low modulus makes their performance characteristics different from those of steel fibers, and that they are not likely to be economical in linings where crack widths are limited, but that they are preferable where large deflections are permissible.
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Fiber-reinforced shotcrete (FRS) has been used successfully for ground support for more than