About the Exciting Career Opportunities for Shotcrete Professionals

Shotcrete professionals are highly valued members of the team at The Conco Companies. Shotcrete is the term used to define the entire act of spraying concrete or mortar instead of pouring by hand.

What is a Shotcrete Nozzleman?

A nozzleman is a person who understands the process of making and placing wet-mix shotcrete via a nozzle. Different kinds of shotcrete methods require different kinds of skills. For example, a nozzleman working with wet-mix shotcrete will be spraying a pre-mixed solution onto the surface. Gunite, on the other hand, is a dry-mix process in which the dry mix and the water are mixed on-demand from the nozzle. This process requires a highly skilled shotcrete professional with experience with this process.

The Conco Companies Are Always Hiring Shotcrete Professionals

Conco is one of leading commercial concrete contractors in the Western US. As Conco expands in the region, we need qualified, hardworking professionals to join our growing team. We are seeking qualified shotcrete professionals at all of our locations in Northern California, Southern California, Washington, and Colorado. A qualified candidate must have requisite shotcrete experience. In addition to shotcrete work, Conco has job openings for qualified cement masons, ironworkers, laborers, engineers, and more.  With the exception of Colorado, these are all union positions offering competitive wages, medical, and retirement benefits. Please visit our website for further details on open positions and appropriate contact information.

Conco is 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.

Understanding the LEED’s Rating System

The Conco Companies offer our concrete services to projects throughout the Western U.S. and many of the prominent buildings we help to construct have received high LEED certifications.  The following is a short description of some of the criteria that is used in the rating system to determine LEED certification for buildings.  

LEED is an acronym for Leadership in Energy and Environmental Design and was started in 1998 by the U.S. Green Building Council (USGBC).  According to the USGBC, the green building certification program recognizes best-in-class building strategies and practice that have a positive impact on the health of occupants, while promoting renewable, clean energy.   

LEED offers third-party guidelines for the building industry to strive to design, construct, and operate buildings that provide the most optimal environments as possible while at the same time save money and resources.  With a membership of almost 20,000, the USGBC reviews and publically updates the standards every few years.  The key issue they promote is energy efficiency and protecting or using renewable resources. Today LEED certification is sought after and a higher endorsement can increase a building’s market value.

Buildings receive LEED certification based on specific guidelines and the higher the points for achieving those goals, the higher the certification.  Levels of endorsement include Certified, Silver, or Gold – right through to Platinum, the highest award.  The five basic categories of how points are earned are:  Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, and Indoor Environmental Quality. 

Energy-efficient appliances and heating and cooling systems increase LEED certification as does using recycled materials.  Extra points can be achieved through special recognition of Innovation in Design and Regional Priorities.  Regional points are earned when a builder has taken care to lessen or eliminate the harmful impacts on a sensitive, local environment.     Endorsements are offered on residential homes, commercial and industrial buildings and entire neighborhood projects.

Conco is a leading supplier of concrete services for the Western United States. 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, Washington, Oregon, Nevada and Colorado.

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.

How Do We Determine Which Pump to Use?

For any of you following our articles on Conco Now or our blog posts, you know that we have an impressive fleet of concrete pumps that has allowed us to successfully operate one of the largest concrete pumping companies in the U.S. for more than 40 years.  In fact in Southern California alone, we house 15 pumps manufactured by two of the top names in the industry, Putzmeister and Schwing.  So with all of the pumps that we own, how do we determine which is the best pump or pumps to use on a particular job?

This is where our experts come in.  They know how to deliver cost-effective solutions for even the most challenging projects.  Our experienced team designs customized plans for each specific project, which includes calculating the needs of a job right down to the type of equipment to use that allows us to meet deadlines and handle access difficulties.

By owning such a large range of different sized pumps, we are able to use the proper equipment to place concrete in the fastest, most efficient manner.  Some of our pumps are specifically designed to maneuver in tight spaces and within small jobsites while the reach of our long booms make them the appropriate choice for other projects. 

This is why it is so imperative to have a team of professional concrete contractors that have the experience to analyze all aspects of the job’s specifications to determine which boom truck has the capability and features to most efficiently handle the job.  Making the right selection of equipment before the job is started is critical to staying on budget and meeting timelines as well as providing a safe environment for our employees and the rest of the workforce at the jobsite. 

The Conco Companies have built an outstanding reputation in the Los Angeles area with our superior concrete formwork, reinforcing, place and finish, shotcrete and other ancillary services.  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.

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.

Why Concrete Shrinks and How it is Addressed

All concrete experiences some degree of shrinkage, which can result in cracks in the concrete.  Shrinkage may also affect the long-term strength and durability of the concrete.  Even though concrete contractors know that shrinkage is caused by a loss of volume that occurs in different stages of the process, it is still challenging to prevent or alleviate shrinkage, and thereby the cracking.  It is especially an important consideration when constructing industrial floors or pavement.

Since shrinking is one of the inherent properties of concrete, it is impossible to totally eliminate cracking but it can be controlled.  This is why contractors and engineers work to understand and address the volume change in concrete to reduce the amount of shrinkage.

According to the Portland Cement Association, “The shortening of concrete slabs can be caused by temperature decreases or moisture loss. These two causes are also related to curling and warping of slabs, respectively. Curling is the deformation of the slab due to a difference in temperature between the surface and the bottom of the slab (temperature gradient).  Slab “warping” is the deformation of the slab surface profile due to a difference in moisture between the surface and bottom of the slab (moisture gradient).”* 

To quickly move and place concrete, it is mixed with more water than is absolutely necessary for hydrating the cement materials.  Once the concrete is placed, the excess water separates from the hardening concrete, which results in a loss of volume that causes the concrete to shrink.  The concrete’s reinforcement or base friction works to restrain it, which in turn can create tensile stresses in the slab causing cracks. 

In an effort to prevent the shrinkage, one of the things that contractors watch out for is fluctuating temperatures during the first 24 hours after placement.  Also considerable care is taken to use the correct concrete mixture design so that the least amount of extra water is added and the largest size of aggregate is used.  All of this works toward reducing shrinkage.

*http://www.cement.org/for-concrete-books-learning/concrete-technology/focus-on-floors/concrete-shrinkage

 

Conco is one of the leading commercial concrete contractors in Sacramento and has been delivering first-rate services in the area since 1959.  We 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.

 

Is it Possible to Protect Homes from Damaging Tornados?

While architects are continuing to make strides in designing large commercial buildings that can provide more protection from natural disasters, the powerful EF4 and EF5 strength tornados that have occurred through parts of Alabama, Missouri, and Oklahoma over the last few years have demonstrated that single family, wood-framed homes offer little protection.  Not one of those styles of homes that were in the direct path of the forceful storms survived.  Moreover a recent report from Lloyd’s of London regarding the increasing risk of tornados finds that statistically the U.S. has more tornadoes than anywhere else in the world. 

Since many of the wood-frame structures destroyed by tornados were built with the most commonly used minimum standards of the International Residential Code, some people think the standards should be raised.  Though many experts that study the destruction of tornados think it is undesirable to try and build a fully tornado-proof home.  In order to be effective, it would have to be a windowless concrete bunker. 

There are some methods that can make your home more resistant to the damage from strong winds and flying debris that occurs during tornados.  A structural engineer from Simpson Strong-Tie, which makes high-strength metal connectors, suggested in an article from MSN that to resist strong winds, “Homes must be built with what is called a ‘continuous load path.”  The goal would be to create a “series of reinforced connections that tie every element together from roof to foundation, like a chain.”  

While this could be helpful in preventing some of the damage that might occur during a tornado, FEMA recommends that you do not try and tornado-proof your whole house.  Their suggestion is for those in highly prone areas to build a “safe room”.  These rooms can be a retrofitted closet or bathroom or a newly built space in your home and should effectively protect your family against the strongest wind forces.  A safe room does not need to be very large as tornados are over quickly.  They are typically built using reinforced concrete and compared to other ideas are a relatively inexpensive solution for a homeowner.  

Conco is one of the leading commercial concrete contractors in Sacramento and has been delivering first-rate services in the area since 1959.  We 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 and highways.

Why Concrete Cracks

It is a fact that concrete is the best and most widely used building material.  It is far more durable that wood or asphalt and generally requires a lot less maintenance during its lifespan than other types of material.  While we understand the hardness and durability of concrete, we are also aware that it has the tendency to crack. 

Concrete contractors know this and work to mitigate many of the controllable conditions that create the cracks.  They use preventative methods when laying the concrete that can reduce and control the amount and type of cracks.  According to the Portland Cement Association, the most common type of cracks is caused by tensile stresses that develop with the slight change of volume as concrete dries.  This is the reasons that joints are placed in concrete pavement which allows for the shrinkage in a controlled manner, thus reducing cracking.

In most cases, cracks are not structurally damaging and are to be expected in foundations and slabs.  The three basic reasons for cracking are thermal temperatures difference, plastic cracking, and shrinkage cracking.

When cracks occur before the hardening is complete, it is most likely a result of settling or shrinkage in the volume.  The Concrete Foundation Association says that shrinkage of the surface (plastic-shrinkage cracks) is caused by loss of water while the concrete is still plastic.   The types of cracks that occur after the hardening process is completed are generally the result of drying shrinkage, thermal contraction, or subgrade settlement. 

Experienced concrete contractors know all of this and much more.  They understand the proper mix and type of concrete to help eliminate cracking and to prepare the concrete to withstand all the weather conditions it will face over the years.  

Conco is a leading supplier of concrete services for the Western United States. 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 steadily taken a leading role as one of the Bay Area’s top concrete contractors.

The Earliest Cranes

A crane is a type of machine that creates a mechanical advantage for moving heavy objects that are beyond the normal capacity of a man.  It can lift and lower objects and move them horizontally to transports heavy materials from one place to another using a hoist or winder, wire chains, and sheaves (wheels or rollers).  A crane is an essential piece of equipment in the construction industry, the transportation industry, and the manufacturing industry.

The invention of the crane has had important implications on the advancement of our civilization.  It is thought that the most powerful hand crane in history could multiply the force it imparted to the operator by 632 times.  When looking at what the Egyptians accomplished with the building of the Pyramid, 50 men were utilized to move a 2.5 ton stone block, which translates to about 50 kg per person.  During the Roman Empire, a Roman crane increased the lifting capacity of a person to about 3,000 kg or 60% higher. 

Historians believe that the Ancient Greeks were the first to invent cranes in the late 600 BC and were powered by men or animals.  Archeologists have discovered distinctive cutting marks on stones from early Greek temples that prove they were lifted by cranes.  These early cranes were made of wood and enabled the Greeks to construct taller buildings. 

The Romans further advanced the development of the crane that allowed for larger and heavier weights to be lifted.  They invented cranes that were powered by groups of men or animals and used extensive pulley and rope systems.  The Roman Polyspastos crane consisted of 3 ropes and 5 pulleys which were worked by 4 men to move 3,000 kg.  

Conco is one of the leading commercial concrete contractors in Sacramento and has been delivering first-rate services in the area since 1959.  We 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 and highways.