Multi-million-dollar underground stations are currently under construction on Metro and LRT lines in Toronto, Ontario, Canada. Traditionally, the thick, heavily reinforced structural concrete station walls have been constructed using the conventional form-and-pour concrete construction method. This construction method, while widely used, is not without its challenges.
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DownloadSpraying Shotcrete on Synthetic Sheet Waterproofing Membranes
DownloadSpraying Shotcrete Overhead in Underground Applications
DownloadCuring of Shotcrete for Swimming Pools
DownloadForming and Substrates in Pool Shotcrete
DownloadMonolithic Shotcrete for Swimming Pools (No Cold Joints)
DownloadWatertight Shotcrete for Swimming Pools
DownloadSustainability of Shotcrete in the Pool Industry
DownloadShotcrete Terminology
DownloadCompressive Strength Values of Pool Shotcrete
DownloadASA Outstanding Shotcrete Awards Program
The ASA Outstanding Shotcrete Project Awards Program exists to recognize excellence and innovation on projects in which the application of shotcrete has played a significant role.
ASA’s Annual Outstanding Shotcrete Project Awards Program provides an exciting real-world demonstration of the exceptional advantages of placing concrete via the shotcrete process. Many sustainability advantages are also inherent in the shotcrete process and play a significant role in winning projects as well as the project owner’s ultimate decision to use shotcrete as the method of concrete placement. Projects must be completed between January 1, 2022, through September 1, 2024, and can be submitted in the following areas: Architecture │ New Construction, Infrastructure, International Projects, Pool & Recreational, Rehabilitation & Repair, and Underground.
To assist in your submission, we have provided submission resources to inform you of the submission guidelines, a list of questions, and a copy of the owner release form. Please email any questions to [email protected].
Award Archive
2024 – Twentieth Annual Outstanding Shotcrete Project Awardees
Outstanding Architecture | New Construction Project
Math, Science & Shotcrete | Holly Springs, NC
Project Name:
Math, Science & Shotcrete
Location:
Holly Springs, NC
Shotcrete Contractor:
Revolution Gunite
Architect/Engineer:
Dewberry Engineering
Material Supplier/Manufacturer:
Revolution Gunite
General Contractor:
Progressive Contracting
Project Owner:
Wake County Public Schools
Outstanding Infrastructure Project
Ice Harbor Dam Draft Tube Modification | Burbank, WA
Project Name:
Ice Harbor Dam Draft Tube Modification
Location:
Burbank, WA
Shotcrete Contractor:
PCiRoads, LLC
Architect/Engineer:
U.S. Army Corps of Engineers, Walla Walla District
Material Supplier/Manufacturer:
Master Builders Solutions
Equipment Manufacturer:
Gary Carlson Equipment / Putzmeister
General Contractor:
Voith Hydro
Project Owner:
U.S. Army Corps of Engineers, Walla Walla District
Outstanding International Project
Modernization Of the Water Treatment Plant In Poznan | Poznan, Poland
Project Name:
Modernization Of the Water Treatment Plant In Poznan
Location:
Poznan, Poland
Shotcrete Contractor:
SPB TORKRET Ltd
Architect/Engineer:
Sweco Poland
Material Supplier/Manufacturer:
SPB TORKRET Ltd
Equipment Manufacturer:
Sika – Aliva, Atlas Copco
General Contractor:
TERLAN/HYDRO-MARKO
Project Owner:
Aquanet S.A.
Outstanding Pool & Recreational Project
Boundless Waters | Hudson River, NY
Project Name:
Boundless Waters
Location:
Hudson River, NY
Shotcrete Contractor:
Drakeley Pool Company
Architect/Engineer:
Hollander Landscape Architects
Material Supplier/Manufacturer:
Brewster Transit
Equipment Manufacturer:
Schwing Concrete Pumps
General Contractor:
Yankee Custom Builders
Project Owner:
Yankee Custom Builders
Outstanding Rehabilitation & Repair Project
Hemlock Reservoir Dam Improvements | Fairfield, CT
Project Name:
Hemlock Reservoir Dam Improvements
Location:
Fairfield, CT
Shotcrete Contractor:
Patriot Shotcrete, LLC
Architect/Engineer:
Tighe & Bond, Inc.
Material Supplier/Manufacturer:
Sika Corporation
Equipment Manufacturer:
Putzmeister America
General Contractor:
Blakeslee Arpaia Chapman Inc.
Project Owner:
Aquarion Water Company of Connecticut
Outstanding Underground Project
Anderson Dam Tunnel | Morgan Hill, CA
Project Name:
Anderson Dam Tunnel
Location:
Morgan Hill, CA
Shotcrete Contractor:
Drill Tech Drilling & Shoring, Inc.
Architect/Engineer:
AECOM
Material Supplier/Manufacturer:
The Quikrete Companies / Bekaert Corporation (Fibers)
Equipment Manufacturer:
Schwing Concrete Pumping
General Contractor:
Flatiron West Inc.
Project Owner:
Santa Clara Valley WateHr District Tunnel Ground
Honorable Mention Project
Kicking Horse Canyon Mountain Stabilization | Golden, BC
Project Name:
Kicking Horse Canyon Mountain Stabilization
Location:
Golden, BC
Shotcrete Contractor:
LRutt Contracting Ltd* / Ocean Rock Art Ltd
Architect/Engineer:
Aecon/Emil Anderson
Material Supplier/Manufacturer:
Golden Concrete Ltd
Equipment Manufacturer:
REED
General Contractor:
Kicking Horse Canyon Constructors
Project Owner:
Government of Canada
Honorable Mention Project
Goose Pond Dam Improvements | Canaan, NH
Project Name:
Goose Pond Dam Improvements
Location:
Canaan, NH
Shotcrete Contractor:
Patriot Shotcrete, LLC
Architect/Engineer:
Gannett Fleming, Inc
Material Supplier/Manufacturer:
Gannett Fleming, Inc
Equipment Manufacturer:
Western Shotcrete Equipment, Inc.
General Contractor:
Michels Construction, Inc.
Project Owner:
New Hampshire Department of Environmental Services
Honorable Mention Project
Édouard-Montpetit Station – Réseau Express Métropolitain | Montreal, Canada
Project Name:
Édouard-Montpetit Station – Réseau Express Métropolitain
Location:
Montreal, Canada
Shotcrete Contractor:
NouvLR
Architect/Engineer:
AECOM / AtkinsRealis
Material Supplier/Manufacturer:
Bekaert / Lafarge Canada
Equipment Manufacturer:
Various equipment manufacturers including Shaft & Cavern
General Contractor:
NouvLR (SNC-Lavalin, Dragados, Aecon, EBC, Pomerleau)
Project Owner:
CDPQ Infra
Honorable Mention Project
Shotcrete & Waterproofing – Brigade Tech Gardens | Bengaluru, India
Project Name:
Shotcrete & Waterproofing – Brigade Tech Gardens
Location:
Bengaluru, India
Shotcrete Contractor:
Kasturi Projects Private Ltd
Architect/Engineer:
Brigade Properties Pvt Ltd
Material Supplier/Manufacturer:
Prism Johnson Ltd
Equipment Manufacturer:
Epiroc India
Project Owner:
Brigade Properties Pvt Ltd
The Jetcreter – The First Continuous-Feed, Dry-Mix Gun
During the summer of 1970, on my 18th birthday, my father woke me up and told me they needed me on a job. I drove out that morning in July to the Crucible Specialty Steel plant in Midland, PA. It was my first experience working on a Gunite job. We were gunning refractory in a vessel, and I was throwing 100 lb (46 kg) bags of pre-packaged refractory into a paddle mixer to pre-dampen the material. We emptied the paddle mixer on sheets of plywood and shoveled the pre-dampened refractory material into the dry-mix shotcrete gun’s hopper. The Jetcreter was a continuous-feed gun, and it was tough for us to keep up with it. It was a very long day for me because it took 15 hours to complete the gunning. I left the house that morning in the dark and returned home in the dark. That was my introduction to “Gunite” (now referred to as dry-mix shotcrete).
Mapei’s London Underground Bank Station’s Capacity Upgrade
Deep in the heart of London’s financial centre, work has been continuing to make one of the world’s largest stations safer and easier for passengers to use. Finding your way around the existing labyrinth of tunnels, connecting five London underground lines, is a task worthy of the most experienced navigator.
Advances in Shotcrete Technology for Ground Support in Tunnels and Mines in North America
In recent years, shotcrete has been widely used for ground support in civil tunnels and mines in North America. Shotcrete technologies have advanced with robust robotic sprayers, high-performance shotcrete mixture designs, and high-performance fiber reinforcement in conjunction with rigorous qualification of shotcrete nozzlemen and QC inspection and testing programs. Design engineers and contractors are using shotcrete more and more often for various underground applications including ground support and final linings in tunnels in soft ground and hard rock mines, as well as in repair and rehabilitation projects in railway tunnels and other underground openings. Large underground caverns have been constructed using shotcrete as the initial liner in San Francisco and Los Angeles, and for both the initial liner and final liner in New York and Washington D.C. This article focuses on recent underground shotcrete technology developments from project experience and provides lessons learned. It also demonstrates that proper quality control and shotcrete qualification programs are critical for successful shotcrete projects.
Shotcrete’s ability to encapsulate dense structural rebar support makes it an ideal candidate for seismic retrofits or other structural support elements. The high velocity compaction of shotcrete placement and real-time visual inspection of placement make shotcrete a valuable placement method where proper encapsulation is difficult to see and access.
The ASA Technical Questions and Answers is a free service offered to all users, but primarily intended for engineers, architects, owners and anyone else who may be specifying the shotcrete process and/or has need for a possible answer to a technical question.
User agreement: The answers provided to submitted questions are intended for guidance in planning and executing shotcrete applications. This information is intended only for the use of individuals who are competent to evaluate the significance and limitations of its content and recommendations, and who will accept responsibility for the application of the material it contains. The American Shotcrete Association provides this information based on the best knowledge available to them and disclaims any and all responsibility for the information provided. The American Shotcrete Association will not be liable for any loss or damage arising therefrom.
If you are unable to find what you are looking for in the archive, then submit a new technical question.
ACI 318-14 (Building Code Requirements for Structural Concrete) requires post-installed expansion anchors to meet the testing criteria of ACI 355.2-07 (Qualification of Post-installed Mechanical Anchors in Concrete). ACI 355.2 specifies certain anchor testing and evaluation requirements to verify suitable anchor performance and to determine other aspects (such as failure mode) to use in conjunction with Chapter 17 of ACI 318 when designing the post-installed expansion anchors. Anchor testing is required largely to be performed by an independent agency and normally is conducted in normal weight and/or light weight concrete that meet pertinent ACI, ASTM and other requirements. Some post-installed expansion anchor manufacturers (like Hilti) have not had their anchors tested per ACI 355.2 in shotcrete type concrete, only tested in normal weight and light weight concrete. As such, these anchor manufacturers typically do not publish/offer any permitted load ratings, installation torques or other design and installation requirements for their expansion bolts when used in shotcrete. Instead, they recommend site testing to determine anchor performance or that the responsible design engineer can make an engineering judgment on anchor acceptability, as appropriate, if site testing is not performed. Do you have knowledge of any expansion bolt manufacturers that have tested their products is typical shotcrete? If yes to #1 above, do you know if the testing was done per ACI 355.2 requirements?
Shotcrete is a placement method for concrete. With proper equipment and placement techniques, concrete shotcreted in place will have strength, unit weight, permeability, and other hardened properties equivalent or superior to cast concrete consolidated by vibration. Due to delivering concrete material through relatively small diameter lines (1.5 to 2 in.) [38 to 51 mm] concrete mixtures for shotcrete placement typically limit the maximum coarse aggregate size to a nominal 3/8 to ½ in. (9.5 – 13 mm) size.
Thus, answering your specific questions:
- We are not aware of any expansion bolt manufacturers tests that used shotcrete placement of concrete for their test samples. However, tests on cast concrete should be equivalent with a given compressive strength and aggregate size/type in the concrete mixture.
- We expect that as answered in #1, that the tests run with ACI 355.2 requirements in cast concrete would have similar results when used with shotcrete placement of the concrete mixtures with similar hardened properties.
Also, note that ACI 318-19 directly includes shotcrete as a placement method for structural concrete.