Building Facts for the Salesforce Tower

 

The Salesforce Tower in downtown San Francisco is one of The Conco Companies more recent projects and we are currently preparing to do another huge mat pour for the Tower.  This new undertaking will be the largest continuously pumped mat pour done in San Francisco, and by the end of the pour, we will have placed nearly 14,000 cubic yards. 

In recent interview done by the San Francisco Business Times with Michael Tymoff, the senior project manager for the development company, Boston Properties, mentioned that the building could exceed LEED Platinum certification.  Presently the building is pre-certified for LEED Platinum but is intending to add features that are certain to increase the energy efficiency of the Tower such as wind turbines on the roof and other power saving ideas. 

The building is loaded with high-end features that include tall ceilings on each floor that will be as high as 13 feet tall, and 10 foot-high windows throughout the building to offer fantastic views.  Furthermore in an effort to provide exceptional air quality, every floor will have 100% natural air pulled into the building by units that are located on the floor.   

The $1.1 billion project is expected to be complete in 2017 and with a height of 1,070 feet; it will become the second tallest skyscraper west of the Mississippi, just behind the Wilshire Grand Tower.  In addition to the mat pour, Conco was awarded the concrete and rebar contracts for the building.  The building will consist of a concrete core with a structural steel frame that will require lightweight concrete to be pumped to the kinds of heights we have successfully been doing for the Wilshire Grand Tower project in Los Angeles.  

Sources:  bizjournals.com/sanfrancisco/blog/real-estate/2014/07/salesforce-tower-boston-properties-hines-transbay.html?page=all  

Conco is one of the leading concrete contractors in San Francisco offering a range of innovative, quality services.  We have been honored to work on many high-profile projects and were recently awarded the concrete contract for the San Francisco 49ers Stadium.  Our concrete services include commercial, educational, parking and other construction development as well as public works projects.

Benefits That Concrete Boom Pumps Bring to the Industry

Concrete boom pumps bring numerous advantages to today’s construction projects.  This is the primary reason that The Conco Companies continue to make capital investments in our equipment including new concrete pumps to better serve our customers in Southern and Northern California, Washington, Oregon, Nevada and Colorado.

One of the major benefits that modern boom pumps offer is that they place concrete faster than any other method of placement.  Furthermore the concrete requires less handling as the pump does the work of placing it directly where it is needed.  These cost-efficient pumps help projects to be completed faster and to require less manpower of which saves both time and money.

There is such a wide variety of concrete pumps on the market today that there is one designed to handle most any job specifications.  By using the long reach of a boom pump, it allows access to areas on jobsites that would otherwise be difficult to get to.  Boom pumps have the ability to place concrete on to the upper floors of extremely tall skyscrapers and other places that would be next to impossible using other methods. 

The pumps also mean less equipment is used and time is saved in moving those smaller pieces of machinery around a site and having to reset them up again.  There is even better quality control with pumped concrete and the result is a more durable, stronger product.  Less water is needed, which helps to prevent the shrinking and cracking that is common in concrete.  In addition placement is not affected by weather conditions so there are not as many delays in a project.   

Accuracy is also greatly improved by pumping concrete, which typically means fewer delays along the way and results in a more professional outcome.   Last but not least is the fact that pumping concrete is simply the most convenient way to do it. 

Sources:

concretebasics.org/articlesinfo/cp1.php#sthash.ZqQv3feG.dpuf

Conco is one of the leading commercial concrete contractors in the Western United States.  We have four regional offices serving California, Washington, Oregon, Nevada and Colorado and are experts at creating cost-effective solutions that take advantage of the most up-to-date techniques.  Our concrete services include commercial, educational, parking and other construction development as well as public works projects.

San Francisco 49ers Stadium Opens

On August 2, 2014, the Levi’s Stadium hosted the first event to the San Jose Earthquakes VS. Seattle Sounders FC, which is one of the biggest rivalries in major league soccer.  Julio Fuentes, the Santa Clara Stadium Authority Executive Director, said, “The Santa Clara Stadium Authority is extremely pleased to open Levi’s Stadium with an event that showcases one of our region’s very own professional sports franchises, while allowing our community the opportunity to experience the premiere outdoor sports and entertainment venue in the world for the first time.”

The $1.2 billion, 1.85 million sq. ft. stadium in Santa Clara, CA. serves as the new home for the San Francisco 49ers who have already announced a sell out for the 2014 season in the new stadium with standing room only tickets available.  The 49ers kick-off their first game against the Chargers on August 24. 

The large stadium seats approximately 68,500 and features 165 luxury suites and 9,000 club seats.  Contractor on the project was Turner Construction and Devcon Construction, Joint Venture.  Designed by HNTB, an international architecture firm that is known for their multi-purpose venues that emphasis the fan experience as well as green technology.  The stadium was constructed with environmentally friendly features such as the green roof over the suite tower.  There are also three solar bridges used to connect the stadium to the major parking areas.

It was recently announced the stadium has been connected with Santa Clara’s recycled water system, which makes it the first stadium in California to use a drought-proof water source.  A spokesperson for the 49ers stated that the recycled water will account for 85 percent of all the water used in the stadium and will help to move them closer to getting LEED Gold certification.

The Conco Companies were responsible for extensive concrete work on the stadium that broke ground in spring, 2012.  The project consisted of slabs in excess of 2,000,000 square feet and used more than 65,000 cubic yards of concrete.  To meet the ambitious timeline to complete the foundation, Conco worked in four separate areas simultaneously.  The same approach was used for the many deck pours.

 

Conco is one of the leading concrete contractors in San Francisco offering a range of innovative, quality services.  We have built our reputation with superior concrete formwork, reinforcing, place and finish, shotcrete and other ancillary services that benefit from our vast experience.  We have been offering premium concrete services throughout the Western U.S. since 1959, and have four regional offices serving California, Washington, Oregon, Nevada and Colorado.

 

 

Sources:

levisstadium.com/events/event/earthquakes_vs_sounders/

ninersnation.com/2014/6/11/5800760/levis-stadium-faq-49ers-stadium-leed-certified-green-stadium

 

 

Construction is Underway on the Salesforce Tower

Another of The Conco Companies’ projects, the Transbay Tower was recently renamed the Salesforce Tower after the company leased a large portion of the building to become the biggest commercial real estate deal in San Francisco's history.  The new Salesforce Tower is designed by Cesar Pelli of the Pelli Clarke Pelli Architect firm and will transform the city’s skyline to become the tallest building in San Francisco and the second tallest skyscraper west of the Mississippi.

Here are some interesting facts on the new Salesforce Tower:

·        Once completed, the tower will have 1.4 million sq. ft. of office space and Salesforce will occupy 714,000 sq. ft. of it.

·         Building will be 61 floors, and have a height of 1070 feet (326 meters).

·         Salesforce will occupy the floors 1-30 as well as the whole top floor.

·         A new Transbay Transit Center will be located at the base of the tower.

·        According to the architect, the design of the skyscraper has the simple, timeless form of the obelisk, giving the 60-​story tower a slender, tapering silhouette.

·         The walls are composed of clear glass with pearlescent metal accents. 

·         High performance, low-​emission glass as well as the integrated sun shades on each floor will help to reduce the building’s cooling load.

·         Both the tower and transit center will include water recycling systems.

·         The tower is expected to receive LEED Gold certification.

 

Conco is busy laying the groundwork to accomplish another historic feat this coming fall by undertaking the largest continuous mat pour in San Francisco that will be nearly 14,000 cubic yards.  Like the Wilshire Grand Tower in L.A., both skyscrapers will have a concrete core with a structural steel frame requiring lightweight concrete to be pumped at heights that had not previously been attempted on the West coast.

Sources:

 

http://sf.curbed.com/places/transbay-tower

http://pcparch.com/project/transbay-tower

 

Conco is one of the leading concrete contractors in San Francisco offering a range of innovative, quality services.  We have been honored to work on many high-profile projects and recently completed the extensive concrete work for the San Francisco 49ers Stadium.  We have been offering premium concrete services throughout the Western U.S. since 1959, and have four regional offices serving California, Washington, Oregon, Nevada and Colorado.

 

 

Post Tension Cable

Conco is now one of the largest reinforcing steel and post tension cable suppliers in the Western U.S.  Our high-quality post tension (PT) cable meets precise engineering specifications and provides a great value to customers throughout Northern California, Southern California, Washington, Oregon and Colorado.  So what is post tensioning and how is it used in concrete construction?  

Post tensioning is the process of using high-strength, prestressed steel cables or tendons to actively reinforce concrete and apply compression after concrete is poured.  Once the concrete has hardened, the cables are tensioned, or pulled tight with hydraulic jacks and anchored to the outside edges of the concrete.  Pre-tensioned concrete, according to Wikipedia, “is cast around steel tendons—cables or bars—while they are under tension. The concrete bond to the tendons as it cures, and when the tension is released it is transferred to the concrete as compression by static friction.” 

The job of fabricating, assembling, and installing PT cable requires highly skilled workers and specialized tools.  Post tensioned concrete has all the same attributes of reinforced concrete but is used in projects that call for thinner slabs or when a greater span length is called for between support columns.  Many projects could not be done without the use of post tensioning, and it is often the choice for parking structures as it allows flexibility in the design of ramps and span lengths.  The system is also commonly used in stadiums, bridges, and office and apartment buildings.  

Additionally post tensioning reduces the amount of beams needed and allows beams to be placed the full length of a structure rather than from column to column.  Since slabs and other structural members can be constructed thinner, they require less concrete, and thereby, reduce the overall weight of a structure.  It also reduces or eliminates shrinkage cracking and is considered to be active reinforcement.    

* http://en.wikipedia.org/wiki/Prestressed_concrete 

*http://www.dsicanada.ca/uploads/media/DSI-USA_What_is_Post-Tensioning_us_02.pdf

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.

Chemical Admixtures in Concrete

Chemical admixtures are natural or manufactured chemicals that are added to concrete along with portland cement, aggregate, and water.  They can be a liquid or powder and are added to the concrete immediately before or during the mixing process.  The chemical admixtures in a mix will account for less than 5% of the total concrete.   

The purpose of chemical admixtures is to give the concrete additional properties to handle circumstances such as pumping requirements or when placing concrete during extreme weather conditions.   According to the Portland Cement Association, “Admixtures are classed according to function. There are five distinct classes of chemical admixtures: air-entraining, water-reducing, retarding, accelerating, and plasticizers (superplasticizers).”

The National Ready Mix Concrete Association (NRMCA) says that the most common chemical admixtures used are air-entraining agents, water-reducers, and water-reducing retarders and accelerators.  They state that admixtures are added to concrete to increase “durability workability or strength characteristics of a given concrete mixture.”

Accelerators are used to increase the early strength of concrete by causing it to harden quicker and are used to protect concrete from extreme cold or when there is a tight project deadline.  Chemical accelerators are chloride based or non-chloride based and calcium chloride is one type commonly used as it is inexpensive.

Retardants are used to slow down or delay the hardening process such as in situations where the job demands a slower pour due to the scope of the project or when in very hot temperatures.  It provides a crew additional time to place and finish the concrete.   Common retardants are lignin, sugars, and citric and tartaric acids.

Air-entraining is the process of deliberately adding microscopic air bubbles into the concrete.  The purpose of doing this is to increase the concrete’s durability when faced with cycles of freezing and thawing conditions and to improve the concrete’s workability.    Furthermore segregation and bleeding is diminished or completely eliminated.  The only negative is that the concrete experiences a 5% reduction in strength for each 1% of air added.

1. http://www.cement.org/cement-concrete-basics/concrete-materials/admixtures
2. http://www.nrmca.org/aboutconcrete/cips/15p.pdf

Conco is one of the leading concrete contractors in San Francisco offering a range of innovative, quality services.  We have been honored to work on many high-profile projects and were recently awarded the concrete package for the San Francisco 49ers Stadium.  Our concrete services include commercial, educational, parking and other construction development as well as public works projects.

How Concrete Pumps Works

Concrete pumping is a very efficient and reliable means of placing concrete.  One of their advantages is that they provide the ability to access places that other methods would be unable to reach.  A concrete pump can be used for small or large jobs and provides a smooth and even distribution. 

Concrete pumps are the only placement option in very tight, confined spaces or on tall high-rises.  Pumps are the favored method for large volume mat pours and handle these jobs efficiently.  Additionally, concrete pumps can accomplish most placement jobs more economically.  Today’s concrete pumps can place concrete so precisely, there is less need for shoveling and moving it around.  This greatly reduces labor and time.

There are two types of concrete pumps.  One of them is attached to a truck and is known as a boom concrete pump.  It is used on big construction projects to quickly move large volumes of concrete into place.  The pump is operated with a robotic arm that is controlled by a pump operator and is extremely accurate in its placement.  The other type of concrete pump is called a line pump and is mounted on a trailer or truck.  It is operated manually and used on smaller projects such as residential driveways or pools. 

Concrete pump operators are certified by the American Concrete Pumping Association (ACPA), which is the only recognized certification program in the industry.  In order to get certified, an applicant must do the required prerequisite safety training and pass a test before they are given the ACPA endorsement. 

Conco is one of the leading concrete contractors in San Francisco offering a range of innovative, quality services.  We have been honored to work on many high-profile projects and were recently awarded the concrete package for the San Francisco 49ers Stadium.  Our concrete services include commercial, educational, parking and other construction development as well as public works projects.