Use of Dry-Mix Shotcrete to Repair a Lighthouse Structure
This paper presents a description of the repair work carried out in 1996 at the Haut-Fond Prince lighthouse structure located in the St. Lawrence River, 8 km (5 mi) from the coast of Tadoussac, Quebec, Canada. The damaged section of the structure in the tidal zone was repaired using dry-mix shotcrete. Due to the particular field conditions (freezing-and-thawing cycles, ice erosion and im-pact, submersion of the repair zones only minutes after the application of shotcrete, etc.), the mixture used contained high early strength cement, silica fume, steel fibers, a liquid air-entraining admixture, and a powdered set-accelerator admixture. Removal of deteriorated concrete, preparation of the surface, replacement of the reinforcement, specifications for the shotcrete produced, as well as the application procedures are described in this article. A certifica-tion session was held to verify the skills of the nozzlemen. Only those qualified were authorized to apply shotcrete on the structure.
This article describes the repair work carried out at the Haut-Fond Prince structure located in the St. Lawrence River at the confluence of the Saguenay and the St. Lawrence rivers, 8 km (5 mi) from the coast of Tadoussac, Quebec, Canada (Fig. 1).
New Mixture Design and Guide Specifications and Inspector’s Manual
Shotcrete has not traditionally been a material of choice for repair of bridge structures by many state highway departments. One reason for this is that bridge engineers have not been aware of advances in the quality and durability possible with high-performance shotcrete over the last 10 to 15 years. In 1995, an effort was made to help facilitate and encourage the use of shotcrete in bridge repair, especially where it is particularly advantageous: in overhead and vertical surfaces and in thin layers, or a combination of thin and highly reinforced thick layers. The effort was organized by the AASHTO-AGC-ARTBA Joint Committee.
Shotcrete with Steel Fiber Helps Reinforce Mount St. Helens Project Savings
Thirteen-hundred feet (400 m) of the peak collapsed or blew outwards. As a result, 24 square miles of the valley was filled by a debris avalanche of recreation.
Evolution of Fiber Reinforced Shotcrete
The concept of reinforcing shotcrete with discrete, disominous steel fibers was developed by the Battelle Research Corporation in the USA in the early 1970s.
Shotcrete Rehabilitation of a Vancouver, BC Historic
A heritage high-rise building in Vancouver, Canada required rehabilitation due to corroÂsion of the steel frame and cracking in the masonry infill. Brick masonry was segmentally removed from the face of this 15-story-high building to expose the steel beam and column framjng system. Steel corrosion products were removed by needle scaling and sandblasting. New steel plate was welded to the beams and columns where required to strengthen the structure to its original design. Rebar was installed in the previously brick-filled cover to the steel frame and a high quality, low permeability silica fume shotcrete was applied to encase the rebar and fill the void. The south side of the building was
Seismic Reinforcing of Masonry Walls With Shotcrete
Photos and newsclips showÂing hundreds of collapsed homes buryÂing entire families have become all too commonplace. As residents of North America we are thankful that this sort of calamity doesn’t happen here. The earthÂquakes we’re used to seeing (mainly in California) cause inconvenience and in some cases property damage, injury and even some deaths, but nothing as cataÂstrophic as in Turkey this year and Azerbaydzhan a few years back.
Bond Strength of Shotcrete Repair
A good concrete or shotcrete repair must possess three prime charÂacteristics: 1) the repair material must be durable in an aggressive environment, 2) the repair must be well bonded to the substrate and 3) the repair must be as crack free as possible to efficiently protect any embedded steel reinforcement from corroding.
Repair of Bridge Elements Using Shotcrete
This article presents the essential elements necÂessary for successful remediation of bridge elements. It should be noted that all strucÂtural elements whether f om bridges or other strucÂtures can have certain commonality. However, with bridges, there are certain environmental characterÂistics that enhance the potential for distress. Bridge elements have a certain sensitivity to damage caused
Rehabilitation of Sanitary and Storm Sewers Using Shotcrete
The infrastructure of the United States is crumbling above, below, and around us. A considerable segment of the public and private engineering community is currently engaged in solving a geoÂmetrically increasing problem with geometrically decreasing funds. The problem is often compounded since maintenance of public works facilities must be paid for using public funds. This article will introduce a process for solving these problems that has actuÂally been around for many years-the process of using shotcrete or gunite to rehabilitate old, damaged, or otherwise substandard existing sewers.