Reinforcing Steel in Concrete

Reinforcing steel is used in the construction of bridges, buildings, skyscrapers, residential homes, warehouses, foundations and roads to increase the strength of the concrete in addition to providing the support to hold the structure up.  It offers many economic advantages, and the high-tech process used to create the steel bars of today has been totally transformed from the reinforced concrete building that was done in the late 1800’s. 

As reinforced concrete is typically a locally sourced material as well as the fact that the steel comes from recycled scrap, makes it both a sustainable and environmentally friendly product.  In addition once a structure is no longer viable, the reinforcing steel and concrete are separated and both materials are recycled to be used again. 

The reinforcing steel bars known as rebar are installed inside the concrete, and work to help the concrete maintain its shape.  It is both an economical way to increase the strength of the concrete and provides the opportunity to build structures that could not have been done without it. 

The Concrete Steel Reinforcing Institute (CSRI) explains that, “Steel Reinforcing bars are produced by pouring molten steel into casters and then running it through a series of stands in the mill, which shape the steel into reinforcing bars. The cross hatchings, called "deformations," help secure the steel and transfer the load between it and the concrete.” 

Reinforced concrete offers the durability and strength of the concrete and the reinforcing bar working together.  The CSRI adds that, “The concrete provides the material's compressive strength, while the steel — in the form of embedded reinforcing bars — provides tensile strength.”

Sources:  crsi.org/index.cfm/steel/about

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.

 

 

More Concrete Terminology

 

 

The Conco Companies have been providing the best value on concrete services and products along the West Coast since 1959.  We are honored to be a part of many noteworthy projects being constructed throughout the area and bring that same commitment to all of our projects regardless of the size.  Our vast portfolio includes work on parking structures, educational and healthcare buildings, high-rises as well as public sector work.

We have taken the opportunity to do a couple of blogs providing definitions for some concrete specific terms.  Here is our last post regarding some indispensable concrete terminology that is taken from the American Concrete Institute’s ACI Concrete Terminology. 

Load balancing — a technique used in the design of prestressed-concrete members in which the amount and path of the prestressing is selected so that the forces imposed upon the member or structure by the prestressing counteract or balance a portion of the dead and live loads for which the member or structure must be designed.

Mass concrete — any volume of concrete in which a combination of dimensions of the member being cast, the boundary conditions can lead to undesirable thermal stresses, cracking, deleterious chemical reactions, or reduction in the long-term strength as a result of elevated concrete temperature due to heat from hydration.

Metakaolin — a natural pozzolan produced by heating kaolin-containing clays

Natural pozzolan — a raw or calcined natural material that has pozzolanic properties

No-slump concrete — freshly mixed concrete exhibiting a slump of less than 1/4 in. (6 mm).

Plastic shrinkage — shrinkage that takes place before cement paste, mortar, grout, or concrete sets.

Portland cement — a hydraulic cement produced by pulverizing portland-cement clinker and usually with addition of calcium sulfate to control setting

Pozzolan — a siliceous or silico-aluminous material that will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form compounds having cementitious properties (there are both natural and artificial pozzolans).

 

Precast concrete — concrete cast elsewhere than its final position

Reinforced concrete — structural concrete reinforced with no less than the minimum amount of prestressing steel or nonprestressed reinforcement as specified in the applicable building code.

Scaling — local flaking or peeling away of the near-surface portion of hardened concrete or mortar

Slump — a measure of consistency of freshly mixed concrete, mortar, or stucco equal to the subsidence measured to the nearest 1/4 in. (5 mm) of the molded specimen immediately after removal of the slump cone

Sources:  concrete.org/tools/concreteterminology.aspx  

Discover the experience of working with one of the top professional commercial concrete contractors in Northern and Southern California, Nevada, Oregon, Colorado and Washington.  Conco has been in business since 1959 delivering first-rate concrete services and has all the experience and expertise to handle even the most challenging projects.

Air-entrained Concrete

The Portland Concrete Association (PCA) defines air-entrained concrete as containing billions of microscopic air cells per cubic foot.  These tiny chambers or microscopic bubbles act as reservoirs to allow water to expand when subjected to freezing temperatures and helps to relieve some of the internal pressure on the concrete. 

Air-entrained concrete is not only designed to make concrete more resistant to freeze/thaw cycles but also to make it more deicer-scaling resistant.  In addition the air-entraining concrete acts as a lubricant in the mix to improve the workability while the concrete is still plastic and increases its slump (a measure of the consistency of fresh concrete). 

Air-entrained concrete is produced by using air-entraining portland cement or by the introduction of air-entraining agents (chemical admixtures).  The amount of air bubbles are generally in the range of 10 to 500 micrometres in diameter (0.0004 to 0.02 in) and are spaced very closely together.  These air pockets or bubbles relieve much of the pressure from the freezing water by giving it a place to safely flow into.  The PCA explains that, “The amount of entrained air is usually between four and seven percent of the volume of the concrete, but may be varied as required by special conditions.”

The procedure was first started in the 1930’s, and today, most concrete is air-entrained particularly the concrete that is used for exterior projects in colder climates.  Another advantage it offers is that with the increased slump, it allows less water to be used in the mix to produce a higher strength concrete.  The benefit of less water in the mix also means there is less drying shrinkage.  Air-entrained concrete is also used to protect against sulfates and alkali-silica reactivity.

Sources:

cement.org/cement-concrete-basics/working-with-concrete/air-entrained-concrete
en.wikipedia.org/wiki/Air_entrainment
nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs141p2_023438.pdf

The Conco Companies are 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.

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.

How Pozzolan Additives are Used in Concrete?

 

 

To understand what a pozzolan is and how the addition of one can benefit concrete, we need to define the term.  The American Concrete Institute defines a pozzolan as, “a siliceous or silico-aluminous material that will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form compounds having cementitious properties”  Pozzolan are found in natural, artificial and silica fume substances.  To have pozzolanic properties, the material must be amorphous (lacking a crystalline structure, without solid form) to create the required chemical reaction. 

The word “pozzolan” comes from the name of a town in Pozzuoli, Italy that is located near the site of Mount Vesuvius and is where the Romans mined ash from the volcanic activity to use in the construction of many of their buildings.  Natural pozzolans are found in materials such as volcanic ash, pumice and tuffs as well as inorganic material such as calcined clay and shale and metakaolin.  

 

Artificial pozzolans are found in materials that include Class C fly ash, Class F fly ash, ground slag, and silica fume and rice hull ash.   All of these materials are waste or by-products of industry.  Silica fume is a waste product of the silicon metal industry while fly ash results from the burning of coal in electric power plants. 

The addition of pozzolans to concrete has many benefits.  One of the foremost benefits is they offer an economic savings as they replace a substantial portion of the more costly portland cement.  Pozzolans can also create a higher strength concrete and increase durability by being more resistant to the environment.  Furthermore since they decrease the water content that is needed in the concrete, they help to reduce drying shrinkage.    

Sources:

concrete.org/topicsinconcrete/topicdetail/pozzolans
en.wikipedia.org/wiki/Pozzolan
ferrocement.net/ferro/files/pozzolans-uwe.html

Since 1959, The Conco Companies have been leading commercial concrete contractors in the Western U.S. offering a wide range of innovative, quality services.  We have built a reputation on superior concrete formwork, reinforcing, place and finish, shotcrete and other ancillary services that benefit from our vast experience.  Our regional offices are in Southern and Northern California, Washington, Oregon, Nevada and Colorado. 

The Addition of Fly Ash to Concrete

Over the last several years the use of fly ash in concrete has been fully documented to demonstrate a benefit in both the mechanical and durable properties in concrete structures according to the National Ready Mixed Concrete Association (NRMCA).  So what is fly ash and how wide-spread is its use in concrete?

Fly ash is defined by the Cement and Concrete Terminology (ACI Committee 116) as “the finely divided residue resulting from the combustion of ground or powdered coal, which is transported from the firebox through the boiler by flue gases.”  It is the ash that is produced from the combustion of coal-fired electric generating plants and there are two classifications of fly ash produced depending on the type of coal that is used. 

All fly ash has a significant amount of silicon dioxide (SiO2) and calcium oxide (CaO) but Class F fly ash is produced from anthracite and bituminous coal and Class C fly ash from burning younger lignite or subbituminous coal.  It is Class C fly ash that is preferred by the Green Building Guide and is the most common type offered in ready-mix concrete. 

Sources on Wikipedia cite the benefits of Class C fly ash as, “in addition to having pozzolanic properties, it also has some self-cementing properties. In the presence of water, Class C fly ash will harden and gain strength over time.”  Another benefit of Class C fly ash is it does not require an activator unlike Class F fly ash.

Not only does fly ash offer an environmental benefit of using a by-product of the coal industry but it also improves the performance and quality of concrete.  It is used in the range of 10 to 25% of the cementitious portion of concrete mixtures and more than 75% of concrete uses some portion of fly ash. 

Sources:  nrmca.org/research/cif%20spring%2008%20fly%20ash.pdf

flyash.sustainablesources.com/
precast.org/2013/10/future-fly-ash-use-concrete/

The Conco Companies are 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.

More Concrete Terms

Looking for exceptional commercial concrete services?  The Conco Companies are a leading provider in the Western U.S. and have years of experience in the industry.  We assist our clients with eliminating or reducing technical difficulties and costly delays by creating a solid foundation.  Our excellent in-house services mean you are guaranteed to get the best job.    

In order to understand the industry, it helps to become familiar with some of the concrete terminology.  The following is another list of some important concrete terminology that is taken from the American Concrete Institute’s ACI Concrete Terminology.   

Dense-graded aggregate — aggregates graded to produce low void content and maximum density when compacted. (See also well-graded aggregate.)

Elastic design — design based on a linear distribution of flexural stresses and strains and corresponding limiting elastic properties of the material

Evaporation retardant — a material applied to the surface of concrete before initial setting to reduce the evaporation rate of water without interfering with finishing operations (also called evaporation reducer). (See also monomolecular.)

Fiber-reinforced polymer (FRP) — a general term for a composite material comprising a polymer matrix reinforced with fibers in the form of fabric, mat, strands, or any other fiber form. (See composite.)

Fine aggregate — (1) aggregate passing the 9.5 mm (3/8 in.) sieve, almost entirely passing the 4.75 mm (No. 4) sieve, and predominantly retained on the 75 mm (No. 200) sieve; (2) that portion of aggregate passing the 4.75 mm (No. 4) sieve and predominantly retained on the 75 mm (No. 200) sieve

Flowing concrete —cohesive concrete mixture with a slump greater than 7-1/2 in. (190 mm)

Fly ash — the finely divided residue that results from the combustion of ground or powdered coal and that is transported by flue gases from the combustion zone to the particle removal system.

Formwork — total system of support for freshly placed concrete including the mold or sheathing that contacts the concrete as well as supporting members, hardware, and necessary bracing

Green concrete — concrete that has undergone final setting but not hardened appreciably

High-performance concrete — concrete meeting special combinations of performance and uniformity requirements that cannot always be achieved routinely using conventional constituents and normal mixing, placing, and curing practices

High-strength concrete — concrete that has a specified compressive strength for design of 8000 psi

(55 MPa) or greater

Lightweight concrete — concrete of substantially lower density than that made using aggregates of normal density; consists entirely of lightweight aggregate or a combination of lightweight aggregate and normal-density aggregate; its equilibrium densities are generally between 70 and 120 lb./ft3  (1120 and 1920 kg/m3).

Moisture content of aggregate — the ratio expressed as a percentage of the mass of water in a given quantity of aggregate to the dry mass of that quantity of aggregate.

Sources:  concrete.org/tools/concreteterminology.aspx

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.

What is Slump in Concrete?

 

In concrete terminology, slump is used to describe a measure of consistency in a specific batch of fresh concrete.  To determine the slump, a simple test is done to measure that the proper amount of water has been added to the mix.

The test consists of a steel cone known as an Abrams cone that is 12” in height with an 8” diameter on the bottom and a 4” diameter at the top of the cone.  The cone is placed on a level, impermeable surface and filled in three stages of equal amounts of concrete.  Each layer is tamped down using a special rod to make sure the concrete is compacted.        

At this point the cone is removed and the concrete settles or somewhat “slumps.”  Placing the cone alongside the pile of concrete, the height of the concrete is compared to the top of the slump cone and measured to the nearest 5mm.  Wikipedia states, “The slumped concrete takes various shapes, and according to the profile of slumped concrete, the slump is termed as true slump, shear slump or collapse slump.”  

A true slump is a situation in which the concrete simply subsides but generally maintains its shape whereas in a shear slump the top portion of the concrete shears off.  A collapse slump is as the name indicates and typically means the mix is too wet, or it may be a case of a high workability mix that needs to have a flow test done rather than a slump test. 

Since much of the concrete produced today is a blend of admixtures, fibers and polymers, the aggregate is not the only factor to influence the amount of water added.  Other considerations are taken into account to determine the proper consistency.

 

Sources:

concrete.org.uk/fingertips_nuggets.asp?cmd=display&id=559
en.wikipedia.org/wiki/Concrete_slump_test

 

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.

Concrete Terminology – Learn the Terms

At The Conco Companies, we are involved in many of the most notable projects throughout the Western United States, and as such, we have experience with all kinds of concrete construction.  Furthermore we are committed to using our extensive knowledge to move the concrete industry forward as we demonstrated early this year by setting a world record for the largest continuous mat pour that was executed flawlessly on the Wilshire Grand in L.A.

We are taking the opportunity to go over some concrete terminology and in our previous blog did not even make it past the first letter of the alphabet. Here is an additional look at some essential concrete terminology that is taken from the American Concrete Institute’s ACI Concrete Terminology. 

Backfill concrete — nonstructural concrete used to over-fill excavated pockets in rock or to prepare a surface to receive structural concrete

Basic creep — creep that occurs without migration of moisture to or from the concrete.

Batch — (1) quantity of material mixed at one time or in one continuous process; (2) to weigh or volumetrically measure and introduce into the mixer the ingredients for a quantity of material

Binary mixture — concrete containing two cementitious materials

Blended cement — a hydraulic cement consisting of portland cement uniformly mixed with

slag cement or pozzolan, or both

Calcium chloride — CaCl2, a crystalline solid, is primarily used in concrete as an accelerating admixture.

Calcium stearate — Ca(C18H35O2)2, commonly marketed in powder form, insoluble in water, used as a water repellent admixture in concrete

Cast-in-place concrete — concrete that is deposited and allowed to harden in the place where it is required to be in the completed structure, as opposed to precast concrete

Cement paste — binder of concrete and mortar consisting essentially of cement, water, hydration products, and any admixtures together with very finely divided materials included in the aggregates

Coarse aggregate — aggregate predominantly retained on the 4.75 mm (No. 4) sieve or that portion retained on the 4.75 mm (No. 4) sieve.

Concrete compressive strength — the measured maximum resistance of a concrete specimen to axial compressive loading and expressed as force per unit cross sectional area

Curing — action taken to maintain moisture and temperature conditions in a freshly placed cementitious mixture to allow hydraulic cement hydration and (if applicable) pozzolanic reactions to occur so that the potential properties of the mixture may develop

Drying shrinkage — shrinkage resulting from loss of moisture

Durability — the ability of a material to resist weathering action, chemical attack, abrasion, and other conditions of service

 

Sources:  concrete.org/tools/concreteterminology.aspx

 

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.

Concrete Specific Terminology

The Conco Companies are one of the nation’s premier commercial concrete contractors.  Our scope of projects is vast and we have experience in most every type of concrete construction, and as leaders, we have worked to advance the concrete industry over the last few decades. We are proud of the highly professional team we have in place that has assisted in the development or improved upon much of the industry’s evolvement.

Since many of the terms used in concrete are specific to the industry, we have dedicated a couple of blogs to going over some of the terminology.  What follows is our first list of definitions that is taken from the American Concrete Institute’s ACI Concrete Terminology. 

Abrams’ law — a rule stating that, with given concrete materials and conditions of test, the

ratio of the amount of water to the amount of the cement in the mixture determines the strength of the concrete, provided the mixture is of a workable consistency. (See also water-cement ratio.

Abrasion damage — wearing away of a surface by rubbing and friction. (See also cavitation damage and erosion.)

Absorbed moisture — moisture that has entered the permeable pores of a solid and has physical properties not substantially different from ordinary water at the same temperature and pressure. (See also absorption.)

Accelerating admixture — an admixture that causes an increase in the rate of hydration of the hydraulic cement and thus shortens the time of setting, increases the rate of strength development, or both.

Acceleration — increase in rate of natural progress of setting or hardening of concrete.

(See also accelerating admixture.)

Admixture — a material other than water, aggregates, cementitious materials, and fiber reinforcement, used as an ingredient of a cementitious mixture to modify its freshly mixed, setting, or hardened properties and that is added to the batch before or during its mixing.

Aggregate blending — the process of intermixing two or more aggregates to produce a combination with improved grading or other properties aggregate gradation — see grading

Air entrainment — the incorporation of air in the form of microscopic bubbles (typically smaller than 1 mm [0.04 in.]) during the mixing of either concrete or mortar.

Air-entraining admixture — an admixture that causes the development of a system of microscopic air bubbles in concrete, mortar, or cement paste during mixing, usually to increase its workability and resistance to freezing and thawing.

Anchor — (1) in prestressed concrete, to lock the stressed tendon in position so that it will retain its stressed condition; (2) in precast-concrete construction, to attach the precast units to the building frame; (3) in slabs-on-grade or walls, to fasten to rock or adjacent structures to prevent movement of the slab or wall with respect to the foundation, adjacent structure, or rock.

Artificial pozzolan      — materials such as fly ash and silica fume. (See also fly ash and silica fume).

Sources:  concrete.org/tools/concreteterminology.aspx  

 



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.

Concrete Pumps are Given a Workout on the Panama Canal Project

While we are not a part of the project, we nevertheless find the engineering feat fascinating on both a professional and personal basis.  The expansion of the Panama Canal will not only double the capacity of the Canal but allow larger ships to pass through it.  The $5.2 billion project is now estimated to be closer to nearly $7 billion, and is the largest project on the canal since it officially opened in 1914.  It is expected to be completed in 2015. 

Once completed, the project will add a third lane of traffic by constructing new lock complexes at each end of the Canal.  On the Pacific side, the lock complex will be located southwest of the existing Miraflores Locks and the other will be east of the existing Gatun Locks.   As part of each lock complex, they contain three chambers that move vessels from sea level to the level of Gatun Lake and back down again.  Wikipedia explains, “Each chamber will have three lateral water-saving basins, for a total of nine basins per lock and 18 basins in total. Just like the existing locks, the new locks and their basins will be filled and emptied by gravity, without the use of pumps.”

What really struck us about this project was a short article by Putzmeister regarding their extensive equipment used on the Panama Canal.  This list includes Twelve Putzmeister Telebelt TB 130’s, one Telebelt TB 200, three 58-Meter Boom Pumps, one 52Z-Meter Boom Pump and four Thom-Katt TK 40 trailer pumps.  All of the equipment was used to construct the two 1,400-foot long by 180-foot wide by 60-foot deep channels that will make up the Canal’s third set of locks. 

We may not be working on the canal but our large pumping and belting divisions based out of Seattle, Northern California and the Washington areas have done their share of big projects.  Just in the last several years, Conco has been a part of many of the more notable construction done on the West Coast. 

Sources:  en.wikipedia.org/wiki/Panama_Canal_expansion_project

Discover the experience of working with one of the top professional commercial concrete contractors in Northern and Southern California, Nevada, Oregon, Colorado and Washington.  The Conco Companies have been in business since 1959 delivering first-rate concrete services and has all the experience and expertise to handle even the most challenging projects. 

Conco is Committed to Meeting All New Requirements and Regulations

Safety is always in the forefront at The Conco Companies, and in that effort, we recognize the importance of keeping up with any new changes in safety procedures and regulations.  One important update occurred this past March with the publication of ASME’s B30.27-2014 Jobsite Responsibilities for Material Placement System that outlines specific responsibilities on the jobsite. 

The American National Standard’s most notable change came with the addition of language that was taken from the mobile crane standards to now use in concrete placement.  The new regulation includes a translation requirement for companies that import equipment into the U.S. and a clear description of responsibilities for general contractors, pump operators, and concrete mixer truck drivers as well as for anyone else that is a part of the process. 

The publication, Concrete Facts, explains the new regulation as such, “If specialized training is required, it is shown. Expectations of setup locations are spelled out. What an operator should know, and the items a contractor should consider when ordering a machine are listed. The only way everyone can go home safely after the pour is if everyone knows their piece of the safety puzzle and works to accomplish it.”

The new regulations will go into effect next year but the American Concrete Pumping Association (ACPA) has already stepped up to make sure their safety training programs comply with the new regulations.  Their goal is to see to it that concrete pump operators and ready mix drivers meet the safety training and competency requirements spelled out in the ASME B30.27-2014.   

At Conco, we continue to work at creating the safest work environment for all employees, fellow contractors, customers, and the general public.  As one of the largest pumping and belting companies in the U.S., we implement the highest safety standards in the industry.

Sources:

cfawalls.org/concretefacts/2014/06/30/a-new-american-national-standard-for-material-placement-safety/

mydigimag.rrd.com/publication/?i=216900

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.

Conco’s Pumps are Located to Conveniently Serve the West

The Conco Companies’ pumping and belting division is one of the largest in the United States and is a very important and busy part of our operations.  After our historic Wilshire Grand mat pour, Conco got right to work on the attached parking structure and 73-story building that make up the project.  Our crews will be pumping approximately 80,000 yards of concrete vertically, which includes both lightweight concrete and 8,000 psi mixes. 

On the jobsite, we kept both of the placing boom towers that were used on the mat pour and brought in two additional placing booms to help with the construction of the underground parking structure.  We will use one of our trailer pumps to place shotcrete for the vertical concrete in the subterranean levels. 

In order to conveniently serve the pumping needs of our customers in Southern California, Northern California, Washington, Oregon, and Nevada, we have equipment strategically located throughout these areas.   To serve the Los Angeles area, we have a pumping facility in nearby Gardena and another based out of San Bernardino County.  Two pumping facilities in Martinez and Stockton service the Bay Area and Northern California.  For Washington and Oregon customers, our pumping facilities are based in nearby Kent and Rochester, WA.    

Our impressive fleet of pumps permit us to take on a project of the magnitude of the Wilshire Grand in Los Angeles, the Salesforce Tower in San Francisco, and the San Francisco 49ers Levi Stadium just to name a few.   We continue to expand our inventory of pumps and over the last several years have made large capital investments on equipment such as three brand new Schwing 58X long boom concrete pumps and several new 20, 39 and 47 meter pumps as well as new Telebelts. 

One of our most recent acquisitions included help from us to design and then to purchase the first, two Schwing S 36X pumps with tremmie options that allow us to safely support up to 1,100 at the boom.  All of our new pumps meet the latest emissions standards.

The Conco Companies has built a reputation in the greater Los Angeles area with first-class concrete reinforcing, formwork, place and finish, shotcrete and other ancillary services that benefit from our vast experience.  We have offered premium concrete services throughout the Western U.S. since 1959, and have four regional offices serving California, Oregon, Washington, Nevada and Colorado.

How Do Concrete Pumps Work?

The Conco Companies have been working on the Wilshire Grand in Los Angeles, which is slated to become the tallest build west of the Mississippi.  This project has included our world record largest continuous mat pour last February and since then, moving and placing concrete on each level of the skyscraper. 

For help with the job, Conco purchased a new Schwing M31 concretepump that was specifically designed to handle the heavy lifting of concrete loads that in the past needed the assistance of cranes.  Our new tremmie pump has up to 1,100 pounds of capacity for lifting up to 60’ tremmies of 4” 11Ga. safely without a crane assist. 

So exactly how do concrete pumps work?  A concrete pump is a specialized piece of equipment that is designed to handle the heavy weight of concrete and to keep it moving to prevent it from solidifying.  The process starts with a concrete truck discharging concrete into a hopper that is located on the back of the pump truck.  From there the concrete falls through a mesh gate on the hopper that is used to prevent large pieces of rock from moving into the pump truck hoses.  An auger inside the hopper churns the concrete to keep it liquid and flowable. 

Now that the concrete is in the hopper, “it gets sucked into a valve system in small intervals or strokes. As some of the concrete is being sucked into the valve, the concrete before it is being simultaneously pushed through the concrete pipe on the pump truck boom until it reaches the end of the concrete hose and placed where you need it.”   

The concrete placement continues with the pump operator monitoring the process for any blockages and making sure the hopper stays full.  The safety and stability of the pump is provided by the front and back riggers and the ACPA says that, “Setting the outriggers of a concrete pump with placing boom is one of the most critical jobs of the concrete pump operator and should always be done in accordance with the manufacturer’s recommended procedure.”

The Conco Companies have built a reputation in the Los Angeles area 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:

everything-about-concrete.com/how-does-a-concrete-pump-truck-work.html

concretepumpers.com/sites/www.concretepumpers.com/files/attachments/sb_outriggers_1.pdf