Shotcrete Archives | Page 19 of 21

Shotcrete is the method of applying concrete pneumatically through a high pressure nozzle. It can save both time and money over typical cast-in-place concrete since Shotcrete walls are constructed faster as they need less forming and use less material. Without tie holes (that need to be filled, leaving visible blemishes), it can be an aesthetically appealing alternative.

An exciting new field is developing that takes shotcrete to the next level. Talented shotcrete craftsmen are using sculpted shotcrete as a canvas to create artistic walls that have all of the same structural integrity of a standard shotcrete wall.

The application of sculpted shotcrete is only limited by the imagination. It is a great way to either highlight a structure or blend it into the local landscape with its ability to easily apply color, stains, and textures. Great looking projects are being done with shotcrete that is stained and textured to naturalize an area or to turn plain walls into beautiful murals.

Retaining walls are a great example of where shotcrete’s adaptability and wide range of finished surfaces are designing architectural solutions for stabilizing areas. Rock sculpting and texturing is used to take a functional project and turn it into something that is very artistic and attractive.

When the City of Burien, WA, which sits below the Cascade Mountain range, needed to build a parking garage, they didn’t want a structure made up of stark concrete walls. Their goal was to turn the building into a piece of art that highlighted the city’s most visible landmark, Mount Rainier, and the surrounding mountain ranges. Conco worked to create sculpted shotcrete murals that depicted views of the Cascades, Olympics, and Mount Rainier on all four sides of the building.

For over 50 years, Conco has been providing premium concrete services and is one of the most trusted concrete contractors in Seattle. We partner with clients on every project from the pre-construction stage right through to final completion to maximize efficiency and ensure goals and budgets are met. Our concrete services include commercial, educational, parking and other construction development as well as public works projects.

Coming Out of the Ground in Seattle’s Theatre District

The Holland Partner Group has come out of the ground with a new 40-story apartment building adjacent to the historic Paramount Theatre. This project, with its close proximity to Rapid Ride Transit and Seattle’s retail core, positions itself in the middle of the vibrant downtown. Upon completion this project will consist of 325 apartments, 276 parking stalls, and a restaurant and retail at the ground floor to cater to the theatre clientele.

As part of the Holland Team, Conco is performing all of the cast-in-place concrete, rebar, formwork, shotcrete and concrete pumping for this signature property. The small footprint with minimal lay-down area and five-day form cycle present challenges that require constant communication and coordination with all trades on site. Conco will be utilizing a perimeter protection system and perimeter netting system to ensure the aggressive schedule is met without jeopardizing the workplace. As of August 1, Conco is on schedule having recently completed the 12th floor. Conco will top out the project January 22, 2014.

815 Pine is designed and constructed to achieve LEED Silver status. The project is scheduled to be completed in April, 2015.

Spotlight

New challenges arise for the concrete contractor due to the growing demand for in-fill projects such as Conco’s current Essex-Elkhorn Court Apartment Homes in San Mateo, CA. The City of San Mateo is part of the Bay Area plan drafted by the Association of Bay Area Governments and the Metropolitan Commission designed to find solutions to meet the growing housing needs of the Bay Area. An integral part of their plan is to locate housing near transportation corridors and jobs. The result of doing this would generate a reduction in greenhouse gas emissions due to a less automobile traffic.

Therefore, more projects being constructed are located next to existing commercial buildings and residential complexes. These in-fill projects pose challenges such as noise, site access, and impact on the surrounding neighborhood.

The Essex-Elkhorn Court Apartment Homes will consist of 197 apartment units and have 125,978 square feet of office space with below grade parking for all. The project is being constructed by Barry Swenson Builder.

The Essex-Elkhorn project is sandwiched adjacent to a hospital, day care center and residential housing. Because of this, special attention had to be taken to lessen the impact of performing the concrete work on the surrounding neighbors including scheduling large concrete pours on weekends during designated hours only and reducing the traffic around the site by limiting mixer truck traffic by pumping concrete from one pump to another. The attached clip shows a time lapsed video for accomplishing one of four mat pours scheduled for the project.

Type of Construction:

3” Thick Mud Slab w/ 2” Thick Protection Slab over waterproofing
30” Thick Below Grade Mat Foundation Slab
Two Levels of Below Grade Parking: 8” thick Post Tensioned slabs
Podium Level at Grade: 11” thick Post Tensioned slab
Exterior Basement Walls: Shotcrete applied against shoring walls.
Interior Walls: Shotcrete with Backform
Cast-in-place Columns
Total CY (including mud slabs & shotcrete): 15,500cy

The natural beauty of the Northern California coastline has sometimes wreaked havoc on the coastal communities of Moss Beach and Montara. During the rainy season, mud slides become a frequent occurrence often leading to the shutdown of Highway 1, the only artery leading north to San Francisco.

The resolution to this problem was to build a tunnel through the mountain that will bypass the parts of the coastline most prone to erosion. Public input from local residents reflected a high level of concern that the fix not detract from the natural beauty of the California coastline. Therefore, great attention was made to make sure the tunnel blended in with its surroundings.

Robert T. Hill & Associates, a well-respected artistic firm with 25 of years experience in concrete sculpture, teamed up with Conco on this high profile project. The task at hand was to reconstruct boulder formations out of concrete to blend into the natural formation that existed above the Portal at the south end of the tunnel.

The project was designed by Cal Trans in 2006, but not started until March 1, 2012. Applying shotcrete was extremely difficult as the grade was at 1 to 1 ½ slope. This required the use of man lifts and cranes and sometimes having crews tied off from the top and rappelling down from the top.

The tunnel is scheduled to open in late 2012 before the start of the next rainy season. As a testament to the work from Conco and Robert T. Hill & Associates, the work performed blends into the hillside making it virtually impossible to distinguish between the rocks made by nature and those made by man.

Solution

A city’s history can be told by its venerable buildings that still stand. Over time even the best built buildings succumb to time and stress. Some buildings are worth saving, but cost prohibitive. Retrofit construction costs can often exceed a budget and doom a building. The Hall of Justice renovation project in Los Angeles could have been halted if a cost-effective solution was not designed.

Massive strengthening was necessary to save the 1925-built Hall of Justice. New 24-inch thick shear walls, hammerhead-shaped boundary elements, and drag beams were critical pieces needed to save the ailing structure. These new concrete members will be joined to the existing structure by anchoring approximately 52,000 drill and epoxied dowels.

Conventional methods of placing this concrete would require that forms be erected, adding both time and cost to the project. Additional hurdles would include form material storage, and crew movement through the thirteen building levels. With all of this complexity, it became apparent that pneumatically placed concrete, also known as shotcrete, was the ideal placing method. Shotcrete will allow the construction team to almost eliminate the forming process all together. Once the reinforcing has been installed, the shotcrete can be placed. Furthermore, because shotcrete is placed without a form there are no concrete consolidation surprises.

The Hall of Justice’s structural retrofit would not have been economically possible without the use of shotcrete. Conco’s efforts during the design, its ability to execute, its robust tool set, and immense experience may have given The Hall a new lease on life. Contact us for more information on how we can save or improve your next project.

Follow the progress of The Hall of Justice at CalrkHallofJustice.com.

Newer Posts

Older Posts