2012 Archives | The Conco Companies

Another interesting project that Conco has been involved in recently is the renovation of the Los Angeles Hall of Justice. The building, which was constructed in 1925, is a perfect example of how smart solutions were necessary to save the project. Our collective expertise, experience and cost-effective techniques were put to good use.

The building was heavily damaged, and consequently completely abandoned after the 1994 Northridge Earthquake. Plans for the renovation had been discussed for many years before anything happened. Finally the County of Los Angeles awarded Clark Construction Group California along with design partner AC Martin the Hall of Justice Repair and Reuse Project. Work began in early 2012 and is expected to be completed sometime in 2014.

Conco’s scope of work includes all of the shotcrete, concrete, and rebar. We are also resurfacing the entire existing floor surfaces in the Hall of Justice’s structure and constructing a new 9 story, 1,000 car parking structure on the same site.

Using shotcrete means the walls can be constructed faster and with less material to save both time and money, which is exactly what the renovation of the Hall of Justice needed. It is the method of applying concrete pneumatically through a high pressure nozzle and offers an economic advantage over typical cast-in-place concrete with reduced forming needed. The structural retrofit would have been economically impossible without the use of shotcrete.

The L.A. Hall of Justice has a rich history with all sorts of interesting and notorious visitors that have come through the doors. According to Wikipedia, the building was used in scenes on Perry Mason, Dragnet, and Get Smart. For years, it was the primary county jail housing such infamous prisoners as Charles Mason and Sirhan Sirhan. A cell block that includes the area where Charles Manson’s was kept will be left as a new interpretive center.

Conco is a leading supplier of concrete services for the Western United States. As one of the leading commercial concrete contractors in the San Jose area, we have been involved with large-scale projects in the area including the Mineta Airport. Our concrete services include commercial, educational, parking and other construction development as well as public works projects and highways.

Conco was brought in on another project to help provide solutions that would reduce costs and save time. Devon Construction, owner and contractor of the new complex, Lawson Lane Commons in Santa Clara, CA. contracted Conco for concrete services to build a new parking structure.

The 4-level parking garage will accommodate 2,948 vehicle spaces for the new development that when completely done will consist of 638,958 sq. feet of office space and an amenities facility. The project is being done in two stages with Phase I opened in July, 2012 with two 5-story office buildings and the 2-story amenities building.

Phase II of the Commons will be an addition of two 6-story office buildings and the completion of the campus environment. The high efficiency buildings are expected to see up to a 30% savings in utilities from the Santa Clara power company. This development among several others being done throughout the city is adding to the construction boom under the shadow of the massive on-going 49ers Stadium project.

Conco’s solution to building the parking structure cost-effectively and quickly was to use shotcrete as opposed to cast-in-place concrete. The structure for the Commons has shear walls spanning 310 lineal feet and 40 feet high. The foundations for the walls were poured, and then three more separate shotcrete pours were done over the course of 25 business days using a total of 390 cubic yards of concrete.

Our design team and estimators projected that using shotcrete saved 24% over what the more traditional approach of cast-in-place walls would have cost. We saved time and also saved labor cost by eliminating several of the days it could have taken to complete the project. Furthermore, the shotcrete walls have the same structural characteristics as traditional cast-in-place walls.

Conco’s team of professional concrete contractors in the Portland area brings the highest level of integrity and principles to each project from pre-construction to finish. With the rapidly growing construction market, Conco is taking an active role in the Portland area with our expansion of high-quality commercial concrete services.

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.

Looking for a Faster, Economical Solution?

A new parking structure being constructed in Santa Clara, CA offered challenges similar to many other projects. The owner and the general contractor, Devcon Construction, were looking for ways to get the structure built more quickly and economically. One solution used was to build the 40 feet shear walls using the shotcrete method as opposed to being cast in place.

The project, Lawson Lane Commons, has shear walls spanning 310 lineal feet and 40 feet high. Foundations for the walls were poured on 5/25/2012 and three separate shotcrete pours were done with the final shoot being completed on 6/28/2012. In total, 390 cubic yards of concrete were shot and the walls were completed in only 25 working days.

In reviewing this project, our estimators projected that comparable cast-in-place walls would have taken 24% more man hours to complete. The additional man hours would have equated to higher labor costs and several more days on the schedule to complete the task. By using shotcrete provided by Conco, the general contractor was able to have the shear walls completed in less time than anticipated, saving time on the overall schedule. Furthermore, the shotcrete walls have the same structural characteristics as traditional cast-in-place walls.

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