Increasing the Strength of Concrete

There are several ways to control the strength of concrete.  One of the easiest is to add more cement to the mix and reduce the ratio of water to cement in the cement paste.  In fact the Portland Cement Association states that, “Every desirable physical property that you can measure will be adversely affected by adding more water.”

In addition to the water/cement ratio affecting the strength of concrete, it is also influenced by the quality of raw materials, the ratio of coarse/fine aggregate, temperature, relative humidity, compaction of concrete and the curing process.   Factors such as how the cement is stored (should be under dry conditions) and whether it was manufactured to the appropriate standards, the quality of the aggregate regarding size, shape, texture and strength, to the purity of the water, can all impact the strength of the concrete. 

The coarse/fine aggregate ratio will determine the amount of water that is needed.  When the fine aggregate is increased in relation to the coarse aggregate, the aggregate surface increases and demands more water.  This higher water demand means the water/cement ratio is increased, which in turn decreases the compressive strength of the concrete. 

Another factor that can impact strength is compaction of concrete.  If there is poor compaction of the plastic concrete, air is entrapped and reduces the strength of the concrete.  It is estimated that the strength of concrete that contains 10% trapped air can be affected by as much as 30 to 40%. 

Concrete contractors also consider air temperatures and relative humidity as both can affect the strength of the concrete.  While higher temperatures allow concrete to gain strength more quickly, the final strength of the concrete is actually lower when hydration occurs at a faster pace.  This is due to the hardened cement paste being less structured as well as more porous. 

At The Conco Companies, we are one of the leading concrete contractors in the Western U.S. and offer a wide range of quality services and products.  Our experience includes providing services for commercial, educational, parking and other construction development as well as public works projects.  We serve California, Washington State, Oregon, Colorado and Nevada.

Sources:cement.org/for-concrete-books-learning/concrete-technology/faqs

theconstructor.org/concrete/factors-affecting-strength-of-concrete/6220/





A Sample of Conco Reinforcing’s Range of Expertise

At Conco Reinforcing, we have been busy providing reinforcement for a range of projects.  One recently completed project was on the $4,500,000 Sacramento Water Treatment Plant in Downtown Sacramento, CA.  Overaa Construction was the development company for the project that began in July 2014 and was recently completed in March 2016.  The City of Sacramento WTP improvements include filter lagoons, gravity thickeners, sludge pump stations, dewatering building, sedimentation basins, a filtration complex, and high service pumps stations along with many other miscellaneous structures.   

Overaa states that the new plant has a design-rated capacity of 160 millions of gallons per day and includes a new solids handling system.  The project entailed removing an old sedimentation basin to make way for the new facility and demolition of existing structures.

Another recent project that Conco Reinforcing is involved in is providing reinforcement on the $426,035.00 Albright Campus Phase II project in Los Gatos, CA.  The General Contractor for the new 242,494 square foot building is Devcon Construction. 

Conco Reinforcing also has lots of experience on highway projects.  One such project is the $6,700,000 Highway 4/I-5 Expansion project in Stockton, CA, which was started in spring of 2014 and will be completed in 2016.  Brosamer & Wall is the development company on the project that will provide a new Green Valley Road Overcrossing, West Bound 80 to West Bound 12 Separation, and a Green Valley Road Overcrossing South Bound 680.

One of our other recent highway projects is the Highway I80/SR12 Separation Interchange in Cordelia, CA.  Viking Construction is the development company for the $2,200,000 project that started in November 2014 and completed in 2016.  The project includes the Green Valley Road Overcrossing, West Bound 80 to West Bound 12 Separation, and the Green Valley Road Overcrossing South Bound 680. 

Take a look at The Conco Companies’ project page on our website to see the extent of all our projects.  Conco has earned a reputation for providing premium concrete formwork, reinforcement, pumping, finishing, trucking, shotcrete and design/build services. 

The Conco Companies are one of the foremost suppliers of concrete services for the Western U.S. We got our start in 1959 in the Bay Area by offering clients the best value on a broad range of concrete services and products.  Since that time, we have taken a leading role as top concrete contractors in the region. We have four regional offices serving California, Oregon, Nevada, Colorado and Washington.





One Year from Finish – Update on the Wilshire Grand

Pouring an impressive 150,000 cubic yards of concrete thus far, we recently topped off the core of the 1,099 ft. tall (including the 160 ft. spire) Wilshire Grand Center.  The Conco Companies are supplying all of the cast-in-place concrete on the downtown L.A. skyscraper that will become the tallest building west of the Mississippi.  It replaces the U.S. Bank Tower, which currently holds that honor.  The Grand is just a year from its scheduled finish date of March 2017, and with the topping off of the concrete core, crews have started on the interior finish work.

The scope of our project includes providing the high-strength concrete that was used inside the core walls as well as providing the lightweight deck-fill concrete for all of the 73 floors.  In addition Conco was responsible for doing all of the structural deck concrete including below grade walls and columns.  Shotcrete will be applied to the perimeter walls.

The Wilshire Grand Center, a $1.2 billion, 73-story mixed-use building, is the first Class A space that has been constructed in downtown Los Angeles since 1997 and will add to the cultural and economic revival of the area.  An observation deck and bar is planned for the top floor with double-decker express elevators to quickly take you up there.  A hotel will occupy floors’ 31 to 70, and lower floors reserved for office space.  At ground-level there will be a public plaza featuring a 240-foot-long atrium skylight. Above 7^th and Figueroa streets, a large LED billboard will light up the area. 

As the General Contractor, Turner Construction’s Project Superintendent, Marc Turcot reports, “It’s on schedule, which is quite the victory.”  We, along with every else involved in the project, cannot wait to see the finished product!

The Conco Companies are one of the foremost suppliers of concrete services for the Western U.S. We got our start in 1959 in the Bay Area by offering clients the best value on a broad range of concrete services and products.  Since that time, we have taken a leading role as top concrete contractors in the region. We have four regional offices serving California, Oregon, Nevada, Colorado and Washington.

Source:lamag.com/citythinkblog/l-a-s-tallest-tower-isnt-finished-yet-but-its-already-transforming-the-downtown-skyline/



Plans for an Even Taller Skyscraper in Dubai

Emaar Properties, financed by the United Arab Emirates, recently announced its intention to build a new skyscraper in Dubai that will be taller than its Burj Khalifa, which currently holds the record as the tallest building in the world.  While the Burj Khalifa stands at an impressive 2,716 ft. (828m) tall, the $1 billion proposed project is slated to be a notch taller and to become the iconic centerpiece of the Dubai Creek redevelopment project.   

Construction on the new tower is scheduled to begin mid-summer and to be finished in time for the Dubai World Expo that takes place in 2020.  The ambitious project, designed by the Spanish architect Santiago Calatrava Valls, includes glass balconies that will rotate outside the wall of the tower.  In addition the skyscraper will have a boutique hotel and 18 to 20 floors of high-end shops, restaurants and other tourist attractions.  

The chairman of Emaar Properties, Mohamed Alabbar, explained that the design of the new tower will not look like a traditional skyscraper such as the Burj Khalifa, but rather be “more of a cable-supported spire.”  The tower will “feature a slender, streamlined structure with a needlepoint-like tip, and will offer ‘garden’ observation decks decorated with trees and other greenery.” 

Other projects from the award-winning, neo-futuristic architect, Santiago Calatrava (also a structural engineer, sculptor and painter) include the Athens Olympic Sports Complex and the City of Arts and Sciences complex in Valencia, Spain.  He also designed the Museum of Tomorrow in Rio de Janeiro that just opened in December 2015.  The museum has a number of 'green' features such as “pools to capture rainwater for use in the plumbing system, and also pools that naturally filter water from the bay.”

The Conco Companies are a leading supplier of concrete services for the Western U.S. We got our start in the Bay Area in 1959 by offering clients the best value on a wide range of concrete services and products.  Since that time, we have taken a leading role as one of the top concrete contractors in the region. We have four regional offices serving California, Nevada, Washington, Oregon and Colorado.

Image Credit: Emaar Properties

Sources:telegraph.co.uk/travel/destinations/middle-east/united-arab-emirates/dubai/articles/new-dubai-skyscraper-to-surpass-the-worlds-tallest-building/

nydailynews.com/news/world/dubai-aiming-new-heights-tower-article-1.2595744

en.wikipedia.org/wiki/Santiago_Calatrava





Trustworthy, Experienced Concrete Solutions for the Front Range

The Conco Companies have been busy over the last several years.  In order to meet the needs of the growing construction market, we have increased operations all along the West Coast and continue to upgrade and expand our facilities and equipment.  In addition Conco has also expanded our geographic footprint to include Nevada and Colorado, which aligns with our mission to be the best supplier of concrete services in the Western United States.    

Our Colorado operations are based out of Denver in nearby Englewood and bring to the Front Range our expertise, experience and excellent reputation to provide the area with the best value on concrete solutions.  We provide the area everything from professional design/build services to quality concrete formwork, reinforcement, shotcrete and finishing along with other ancillary services. 

The Conco team consists of experienced professionals and some of the most seasoned crews in the industry.  For even the most challenging projects, we have the tools and resources to successfully handle it.  Furthermore, by owning and operating two modern, state-of-the-art rebar facilities, it means we are of the largest reinforcing steel and post-tension cable contractors in the West and can meet your needs quickly and efficiently.  While we are relatively new to the Denver area, we were proud to be involved in the construction of the luxurious high-rise apartment building, the Platform at Union Station, which is a part of the Union Station Neighborhood project.   

In concert with our clients and trade partners, Conco has not only broken world records but continues to challenge our team to come up with new, innovative solutions.  We are proud to bring that same work ethic and high standards to our Colorado projects. 

The Conco Companies are a leading supplier of concrete services for the Western U.S. and got our start in the Bay Area in 1959 by offering clients the best value on a wide range of concrete services and products.  Since that time, we have taken a leading role as one of the top concrete contractors in the region. Our offices serve California, Colorado, Oregon, Washington and Nevada.





Hot Weather Safety Procedures

At The Conco Companies, we take the responsibility of ensuring our employees, customers, and the general public’s safety very seriously, and as such, employ a team of safety and risk management professionals.  Their job is to work with company managers as well as our entire workforce, to eliminate and mitigate risks with a focus on employee safety, claims management and regulatory compliance.

An example of where we really utilize the expertise of our risk managers is on projects such as the East County Detention Center (ECDC) in Indio, California.  Our scope of work for the 516,000 sq. ft. replacement and expansion of the existing Indio Jail Facility includes performing 55,000 cubic yards of concrete services. 

For Conco and our other trade partners, one of the challenging aspects of the ECDC project is to safely deal with desert temperatures.  Indio has an average temperature of 89°F, and in the summer, highs can reach 120°F.  This means we must take extra steps to protect the safety of our crews working in that kind of heat, which is why we have a full-time safety manager onsite. Furthermore, all employees are adhering to OSHA’s hot weather guidelines.

An article by Jim Rogers, director of the Western OSHA Education Center at the Del E. Webb School of Construction, Arizona State University, in Concrete Construction writes how safety precautions must be followed in hot and humid weather.  He warns that heat stroke is the most serious heat-related condition and may result in death if not treated quickly enough.   

As the article advises, Conco crews are provided with plenty of water, rest and shade.  In addition each worker is educated to understand and recognize the signs of heat-related illnesses in themselves or in a co-worker as one of the signs of heat stroke is confusion.  While heat exhaustion is a less serious condition than heat stroke, a person still needs water, rest and relief from the heat.  Symptoms can range anywhere from a headache to nausea, dizziness, weakness, thirst, and heavy sweating.     

The Conco Companies are one of the leading concrete contractors in the Western U.S. and offer a wide range of quality services and products.  We have built a reputation on superior concrete formwork, reinforcing, place and finish, shotcrete and other ancillary services that benefit from our vast experience.   We serve California, Washington State, Oregon, Colorado and Nevada.

Source:concreteconstruction.net/safety/managing-heat-related-illness-in-onstruction_o.aspx?dfpzone=general 





Los Angeles’ U.S. Bank Tower Installs a Glass Slide

This summer, thrill-seeking visitors to L.A. will have the opportunity to slide down a 45-feet-long glass slide that is suspended 1,000 feet above the ground.  The new slide, called the Skyride, is attached alongside the 70^th floor of the U.S. Bank Tower and will take riders down to the 69^th floor.  The one-of-a-kind attraction is made entirely of clear glass that is only 1 ¼-inch thick.  Riders will enter the Skyride on the 70^th floor and slide down to an open-air 360-degree observation deck. 

The slide was installed in March and was quite an unusual sight to see as the 45-foot slide was airlifted by helicopter onto the floor of the observation deck.  The Skyride is only a part of the major renovations that are underway on the Tower, which is currently the tallest building west of the Mississippi.  However once the Wilshire Grand Center opens in spring 2017, it will hold that honor.

The U.S. Bank Tower was bought three years ago by the Singapore-based, Overseas Union Enterprises Limited (OUE Ltd.), and since then, has been going through a $50-million overhaul.  Renovations include a new rooftop complex, known as the OUE Skyspace L.A., which is where the observation deck will be as well as a new bar.  It will cost $25 to get into the Skyspace complex and an additional $8 to ride the Skyride. 

Eventually a restaurant is schedule to be built on the 71^st floor right above the Skyspace complex.  Views from the observation deck are expected to span the San Fernando Valley and all the way to Santa Catalina Island.  In addition an interactive video will be available on the 54^th floor that details the history of Los Angeles. 

The Conco Companies are one of the leading concrete contractors in the Western U.S. and offer a wide range of quality services and products.  While we tackle projects both big and small, our experience includes providing the complete concrete package for the Levi’s Stadium along with other notable projects.  We serve California, Washington State, Oregon, Colorado and Nevada.

Source: latimes.com/local/lanow/la-me-ln-glass-slide-airlifted-20160319-story.html





The Best Example of Doric Architecture

As of late, The Conco Companies have been busy working on several modern day wonders such as providing concrete services on the Salesforce Tower in San Francisco and the Wilshire Grand Center in downtown Los Angeles.  Both buildings are slated to become the tallest structures in the U.S. west of the Mississippi River.  This has revived our interest in many of the architectural marvels built in ancient times.

We know that the three main orders of classical Greek architecture, the Doric, the Ionic and the Corinthian influenced Roman architectural styles as well as those of the Renaissance Period.  In addition it has continued to inspire many of our modern day structures. 

As to one of the best examples of Doric order architecture (featuring heavy fluted columns with plain, saucer-shaped capitals and no base), most experts agree that it would be the Temple of Zeus.  Built in the ancient city of Olympia, it was located in the Altis sanctuary and constructed between 472 and 456 BC.  The purpose of the temple was to house one of Seven Wonders of the Ancient World, the great statue of Zeus. 

The architect on the project was Libon of Elis, who designed the Temple with an east-west orientation and in a “peripteral hexastyle with thirteen columns along the sides.”  Each column, constructed from local shell-limestone and covered in white stucco, was more than 32 ft. high and had a base almost 7.5 ft. in diameter.  The Temple’s roof tiles, pedimental sculptures and lion’s head water spouts were made of marble.  

The interior chamber of the Temple (the cella) was separated into three naves by two double rows of seven columns.  The statue of Zeus sat at the far end of the cella and was believed to be approximately 40 ft. tall.  What we know about the statue is that Zeus was holding a scepter in his left hand and a winged Victory in his right. 

Another architectural detail was in the east gable that had an inscribed block, which supported a gold shield in commemoration of the Spartan’s victory at Tanagra. The Temple of Zeus was badly damaged by fire in 436 AD and completely destroyed by a series of earthquakes in 551 and 552 AD.   

The Conco Companies are one of the leading concrete contractors in the Western U.S. and offer a wide range of quality services and products.  While we tackle projects both big and small, our experience includes providing the complete concrete package for the Levi’s Stadium along with other notable projects.  We serve California, Washington State, Oregon, Colorado and Nevada.

Source: olympia-greece.org/templezeus.html