Nov 27

Concrete Homes – Built to last!

Concrete Homes

Courtesy of Buildipedia.com

With an ever growing population in a constant need for new housing options, a planet that seems to want to shake us of her back with record floods, earthquakes, hurricanes, tornadoes and wild fires, building stronger home as well as conserving non-renewable resources is becoming an absolute imperative. As a result, old and new ideas emerge, and in the field of construction, concrete homes is making a headway.

WHAT ARE CONCRETE HOMES

In addition to pouring the usual concrete slab as the foundation and a driveway, concrete homes replace stick framing with concrete walls that are made with forms. The idea to replace wood structures is by no mean new, adobe homes are some of the oldest dwellings still standing that used rammed earth in lieu of wood. But they require substantial man power and time. Concrete homes on the other hand can be built in very little time with a small crew for about the same price as regular stick framed homes.

NEW DISCOVERY?

Not really! In 1908, while looking for an affordable and durable housing solution, Thomas Edison invented a concrete forming system for homes and patented it! The whole process would take 4 days to erect the mold structure, then pouring the concrete in 6-hour increments, completing the entire project in less than 2 weeks!  In 1937, Frank Lloyd Wright built its famous Fallingwater home in concrete showcasing its strength and ability to create unique shapes that beautiful blend with the surrounding natural setting.

concrete home using insulated concrete forms, ICFs

Setting up insulated concrete forms. Courtesy of saipreethiprecastbuilder.com

HOW CONCRETE HOMES ARE BUILT

To replace the wood structure, insulated concrete forms (ICF) are used. Once the forms are stacked up to form the wall, they are braced on the outside, a moving scaffolding is used to pour the concrete poured into the walls. Some insulated concrete forms incorporate expanded polistyrene (EPS) for greater insulation (R-60). The next day, the walls are set and framing of the interior walls can start and the scaffolding can be moved to the next house. This process could save up to 2 days of work per house!
Watch how a 250 square foot studio home is built in less that 3 hours in this short video.

WHY BUILD A CONCRETE HOME

Concrete homes are tornado and hurricane proof

Concrete home left standing after Katrina.      Courtesy of Conradscastles.com

Ask any long-time home owner what features would an ideal house have and the following is mentioned:
– Moisture, mildew and mold protection
– Termite resistant
– Provide better insulation at the same price
– Eliminate cold spots
– Provide even temperature through day and night.
– Protection against wild fires in drought prone regions (concrete is naturally fireproof)
– Withstand high winds (in hurricane prone regions)
– Meet seismic building code requirements (up to zone 4)
– Better sound proofing
Unbelievable but true, concrete homes address every feature in this list without adding extra cost for each problem.

GREEN BUILDING

Concrete homes are considered green because they recycle cementitious materials like fly ash, slag cement, silica fume that would otherwise be dumped into landfills.

For builders and home owners looking to green their homes, concrete homes completely eliminate the need for volatile preservatives found in the various glues that make up particle wood panels.

With over 9 states in the US experiencing exceptional to abnormally dry weather in 2015, the need for better insulated homes is paramount. When cooling and heating bills in Southern California can be as high as $600-800 a month for a 2,800-square-foot home, the possibility of saving up to 50% of your energy is a huge plus.

DESIGN BENEFITS

Left in its original grey color , concrete can be experienced as masculine, a bit cold and dull, but the use of concrete finishes can transform this material into warm and stunning surfaces that can be combined with wood, glass and other materials.
Concrete homes also offer a greater flexibility in terms of design. Curved walls can easily be incorporated and cheaper to build. They can be very simple and have been transformed into magnificent designs by architects around the world leveraging the surrounding landscape and terrain. Concrete can accommodate very unique modern futuristic designs and angles and can even be used to build monolythic domes.

ISSUES WITH CONCRETE HOMES

Placing concrete in the walls can be challenging and blow-outs can occur. But a experienced operator can take all the necessary precautions to avoid them.

Concrete homes used to cost 3-5% more than standard stick-framed buildings but with a 30-45% energy savings and up to 20% insurance discounts, the monthly operating costs of a concrete homeowner is equal and often even less than regular homes. So cost is no longer an issue when building a concrete home!

MARKET ADOPTION

In a market that constantly sees ups and downs, concrete homes represents a real business opportunity for concrete operators and pumping companies to stand out. Accurate placement of walls requires expertise and know-how. As in all well-established industries, new ideas can be threatening but the benefits of concrete homes so far outweighs the small learning curve builders have to go through to familiarize themselves with ICFs, pouring techniques etc.

More and more environmentally conscious consumers are doing their research and asking for concrete homes that offer energy-efficient solutions, that are much more durable and less toxic. They will only hire contractors that have experience and can do the work. So while most builders may shy away from new techniques and rather do what they know best, there is a growing new market that is waiting to be grabbed.

What size market are we talking? About 14% of the single family homes built in 2002, that’s about 171,000 homes were concrete homes, according to Jim Nicholl, PCA residential promotion manager. So with increasing unpredictable harsh weather patterns we are seeing all over the world and certainly in the US, the need and future for safer and more sustainable concrete homes is real and promising.

If you are looking for great deals on used concrete pumps or aerial lifts,
call United Equipment Sales at: (503)283-2105.

REFERENCE MATERIAL

http://concretehomesmagazine.com/

http://www.cement.org/think-harder-concrete-/homes/building-systems

S.M.L.

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Nov 05

Panama’s New Canal Expansion opening in 2016!

Concrete pumping

Courtesy of Canal de Panama

Originally built in 1914, the Panama Canal has been working at full capacity for years and was plagued by congestion due to an ever growing international trade. The size of ships having also increased over decades (from Panamax to Post-Panamax ships), the creation of a larger third set of locks was the agreed long-term solution. The idea isn’t new since the US started the construction in 1939 but came to a grinding stop in 1942 when it joined the allied forces in WWII. It is now almost completed, but it wasn’t done overnight!

PROJECT GOALS

  • Create 2 new lanes and increase by 1 ½ the maximum width and length of the channels to accommodate Post-Panamax ships. These lanes will be able to carry twice as much cargo and a result double the current canal’s capacity by 2016. In addition to increasing capacity, the third set of locks will also improve productivity, efficiency and safety. It will eliminate the congestion that occurs every year during the high season between December and March that can cause up to a week in delay.
  • Raising 1.5 feet the maximum operational level of the Gatun lake and widening the navigational channel will also increase the water reserve capacity, the quantity of water used by the locks without impacting the supply of water for human consumption.

A GREENER DESIGN

The new channels will each have three chambers and water saving basins. The third lock in each channel will be re-utilizing 60% of the water thus using 70% less water per transit/lock cycles compared to existing locks. The basins will be filled by gravity (without water pumps) like their older counterparts.

IMPORTANT PROJECT MILESTONES: 

Sept 2007 – The project breaks ground.

July 2009 – Contract is signed with Consortium Grupo Unidos por el Canal (GUPA) to undertake the project.

Sept 2009 – Dredging of Canal’s Atlantic entrance starts (removal of approx. 14.8 million cubic meters of material!)

2010 – Dredging of Pacific section completed (4.6 million cubic meters of material).

July 2011 – Start of pouring structural concrete in the third set of the locks project.

Oct 2011 – 1.4 million cubic of water are used to partially flood the channel (1,300 acres area).

Sept 2012 – Extension of the 14 existing gates allowing a 1 1/2-foot increase the Gatun spillway’s maximum operational level.

June 2013 – Both Pacific and Atlantic maritime entrances are now wider and deeper.

2014-2015 – Installation of 16 new gates.

June 2015 – Both Pacific and Atlantic locks are filled and gates are tested.

April 2016 – Official completion of the project.

ELEMENTS OF THE PROJECT:

Panama Canal concrete placing

Panama Canal Expansion Project – Courtesy of Canal de Panama

To create a larger lock, two 1,400-foot long by 180-foot wide by 60-foot deep lock facilities were built. One to access the Pacific side and the other for the Atlantic side. View complete drawings of the Canal new lock system.

SOME CHALLENGES :

Being prone to landslides, unstable banks and flooding, the job site required a mobile and flexible system for placing material. Concrete and gravel was first placed to lay the foundation. Six Telebelts TB 130 telescopic belt conveyors were chosen because they allow the placement of different types of material with one piece of equipment. Also, if changes in terrain conditions were suddenly to occur, the equipment could quickly be teared down, moved and setup again elsewhere.

EQUIPMENT USED: 

Used Putzmeister Katt-kretter pump

Putzmeister Katt-kretter pump

In addition to the 6 Telebelt TB 130 telescopic belt conveyors, Putzmeister America and its Special Applications Business group (SAB) supplied Thom-Katt trailer pumps and boom pumps for a complete pumping solution-based approach.

SOME NUMBERS:

To complete the third Set of locks:
– 39,238 cubic yards were excavated.
– 4,486 cubic yards of reinforced concrete were poured.
– 260 tons of reinforced bars were used.
– 1,060 ton on cement was placed.

With over 47 years of experience in the construction industry, United Equipment Sales has advised on several international large projects similar to the Panama Canal and is always available to help you find the best deal on pumping equipment (pumps, hose and accessories) and aerial lifts. Give us a call!

S.M.L.

 

Jun 04

Wireless Remote Controls For Concrete Pumping

When thinking about the evolution of concrete pumping, from carrying concrete buckets, to the invention of pump trucks, boom pumps, line pumps and more, one can’t help to marvel at man’s ingenuity when it comes to increasing performance, production and safety! As buildings get taller and more complex, equipment becomes more sophisticated to meet the ever growing demand.

Remote controls are one of these practical devices that can assist concrete operators achieve better concrete placing in a safer way. These handheld device transmitters are now standard on job sites for large equipment like loader cranes, tower cranes, overhead cranes, concrete pumps and other mobile equipment.

Below are some examples where using remote controls will make the whole difference:

Pump Trucks
Pump trucks often come equipped with both wired and fixed frequency wireless setups.  One of the problems with fixed frequency wireless controls is communication interruptions and even drop off when operating in heavy radio traffic areas as it is often the case in large cities. Remote controls powered by cables can also be dangerous and must be handled safely. Cables can get entangled in other cables laying around putting the workers at risk on the job site. Wireless controls can solve both problems.

Placing boom truck:
Operators usually hire a spotter equipped with a two-way radio or hand signals to help them maneuver the boom if they cannot leave the pump.

When operators can’t leave the pump truck and have to place the boom, they are faced with the challenge of properly gaging the depth between the boom and the wires. By using a radio remote control, they can stand perpendicular to the boom and know exactly where to place the boom.

A radio remote offers greater control over the flow of concrete, it provides the ability to turn on/off the pump at any time, and usually comes with an emergency stop too.

What to look for when buying remote controls
Some nice features to have are: weatherproof, impact resistant plastic exterior, antenna for extended wireless range, several configuration modes, good charging time, additional outputs etc.
One thing to keep in mind is that some of the best models support Frequency Hopping Spread Spectrum (FHSS) radio technology for the broadest wireless range like the OMNEX products.

Brands of remote controls
There are many models on the market, below are just a few good examples:

concrete pump remote controls

Courtesy of Hetronic – leader in remote controls

Hetronics offers the following models of controls for boom trucks and concrete pumps: With the GL series, GL-3Nova-SNova-L Nova-XL, operators can easily operate booms up to 65 meters (213 feet). All models come equipped with a battery charger and 2 rechargeable batteries.

 

 

 

 

 

 

Putzmeister Ergonic Remote Controls:

Concrete pumping

Putzmeister Ergonic Remote Control

Comes with two joysticks and rotary push buttons.
Provides direct system feedback to operator

 

 

 

Used Concrete pumps

Courtesy of Cooper Industries

OMNEX Trusted Wireless™ remote control
From Cooper Industries

Some models can even regulate the engine speed to minimize fuel consumption and wear.

 

Depending on the job, you many only need a simple remote control, so don’t over kill it. More complex remotes require more time to learn all their features, practice


Troubleshooting the remote
:
The good news is that only a few things can go wrong with a remote control:

– Most often the battery needs to be recharged and after prolonged use and replaced if the charge is holding less and less over time.

– The antenna may not be functioning. Check the antenna and its connection. It could have come loose or been damaged during a project.

So why not incorporate a remote control in your next job? Are you looking for a good concrete line pump, as plaster pump, a gunite pump? Don’t know which one comes with a remote control? Call us (503/283-2105) and we will tell you all about it so that you get in the power seat.

SML

Mar 24

Translucent Concrete

Light-transmitting concrete

Litracon Wall

Innovators in the concrete industry never cease to surprise us. When we first heard of “translucent concrete” we weren’t quite sure how these two words could go together! After all, concrete conjures images of heavy, solid, rough material that blocks just about everything and especially light. What if concrete could let light through? What if a wall could also turn into a window to the outside?

So what is this light-transmitting concrete?

As in all new concrete products, they use variations from the traditional ingredients. One of the main differences is the use of translucent alternatives, like glass or plastic fragments to replace conventional aggregates and let light through with the use of resins or clear glue as binding agents. Another formula involves mixing white Portland cement with white silica sand and fiber glass or plastic rods as reinforcement. Various methods have been developed and patented as a result. In most cases, a thin layer of concrete is poured manually in a mold, then fiber glass is placed on top and another concrete layer covers it. This method allows light to travel from one side of the block to the other.

Another benefit of this promising material is its ability to greatly increase insulation for buildings in harsh regions. This means that privacy is retained while allowing daylight in.That’s pretty cool for Northern regions of the world that suffer from lack of lighting for half the year!

Who are some of the pioneers?

Dr. Price from the University of Houston is not only looking into making translucent concrete, he wants to make transparent concrete made from recyclable materials that can be poured on site (currently it is only available in pre-cast bricks or panels). His vision is that in the future, cities could glow from within from translucent (and eventually transparent) zones within curving walls. A tall order that would undoubtedly revolutionize the building industry.

Other players that are selling blocks and panels include Impact Lighting Inc, Lucem (in Germany), Litracon (in Hungry), just to mention a few.

Usages for translucent concrete. Imagine the possibilities…

Translucent concrete lamp

Litracube

 

What started as a cool medium mostly used in art exhibits, in museums, was then introduced into furniture items like desks, lamps, park benches, counters and now found its way into building walls and floors.

At the Shanghai World Expo in 2010, the Italian Pavilion featured its first application in buildings. When blocks of translucent concrete were inserted into a wall in various geometric positions, soft natural light was let in during the day and a gentle glow appeared at night. The building was transformed into a soothing living structure where the separation between the inside and the outside had been greatly reduced.

Translucent wall

Lucem LED concrete wall

In 2013, the German company Lucem erected the first led infused concrete wall, with 136 color-changing led panels controlled with DMX technology via internet! With one click, these same color panels can be turned into one large display wall that can be used for communication and advertising. The age of giant billboards make soon be over!

What if sidewalks could be lit at night? This is what they did in Stockholm and pedestrians can see their path by simply looking down.

It could be use to bring natural light in underground buildings like train or subway stations. Think about safety uses, anything that could be lit from below, like speed bumps, emergency signs in case of power outage etc.

What if concrete could conduct electricity? It can and as a result airport runways and drives could automatically eliminate snow and ice as it builds up. That’s just one practical application that would save billions of dollars in cold regions of the world!

Some challenges and much promises

Being such a novelty material, translucent concrete is only available in prefabricated blocks and panels. It may take a few more years for it to be poured on site. This makes its price 4-5 times that of its conventional counterpart. However, translucent blocks can be inserted in wall and still obtain the natural lighting effect.

One experimental case had structural strength issues and with the help of chemical additives the problem was corrected. Most formulas (like the Lozoncze’s concrete block from Hungry) have shown impressive compressive and tensile strength without steel reinforcement. Translucent concrete can in fact be used a structural support!

If you are a hands-on person and want to play with the idea of translucent concrete, check out this diy article on the subject.

Getting major concrete manufacturers, engineers and architects to experiment with translucent concrete will lead to its broader adoption and more amazing applications. The future of concrete is bright and truly promising!

United Equipment Sales

 

If you have any questions about concrete equipment, give us a call.

References:

http://www.impactlab.net/2009/03/07/litracon-see-through-light-transmitting/

http://www.lucem.de/index.php?id=219&L=1

http://www.economist.com/node/779421

Feb 28

Self-Consolidating Concrete

self-consolidating concrete

scc concrete

WHAT IS IT?
Self-consolidating concrete was first developed in Japan in the early 1980’s in an attempt to address the problem of lower quality construction due to a shrinking skilled labor pool that is required to create compaction and produce durable concrete structures. Also called flowing or self-compacting concrete, self-consolidating concrete (SCC) doesn’t bleed or segregate. It self-levels and can easily fill form work and confined zones of reinforcing bars due to its high flowability. Its slump is usually greater than 71/2 in (190mm) while maintaining its cohesiveness. In order to obtain a highly viscous paste with high deformability the addition of a superplasticizer is required to keep the water-powder ratio very low. ACI 237R-07 refers to it as “highly flowable, non-segregating concrete that can spread into place, fill the formwork, and encapsulate the reinforcement without any mechanical consolidation.”1

WHAT IS IT MADE OF?
Usually 50% of the solid volume is made of coarse aggregate. Fine aggregate make up 40% of the mortar volume. The water-powder ratio can be set between 0.9-1.0 with the addition of superplasticizer to achieve self-compactibility.

IT IS BEST USED…
To easily fill any form work with heavy reinforcement or in confined zones where vibrating compaction is a challenge. In precast concrete manufacturing facilities and concrete products plants. The smoothness it produces makes it an ideal candidate for architectural concrete. It is most often used for form work, reinforcement, structural design, in columns, beams, wherever lateral pressures need to be predicted and consolidation is obtained by self-weight instead of vibration. In precast concrete manufacturing facilities, the use of self-consolidating concrete is known to improve production rates and lower labor.

HOW TO TEST IT
A traditional flow test won’t work due to SCC’s high flowability. A slump flow test is better suited and can easily be conducted on construction sites. A baseline sample should be taken when placement begins, then left undisturbed, then taken again at regular intervals afterwards. What is being measured is the slump flow and the stiffening behavior of the concrete which can be altered by types of admixture, water content, dosages and temperature. Portable rheometers can be used and installed in forms for added on-site measurements. Concrete conditioning (agitated or not agitated) will impact the test results. New lateral pressures prediction models are being developed (see 2 under references for details ). Over vibrating will not cause segregation with self-consolidating concrete, however, segregation could occur if concrete is pumped over long distances.

Want to find out more about this promising product? Why not attend the 6th North American Conference on Design and Use of Self-Consolidating Concrete on May 15-18, 2016, in Washington D.C.?

Do you have any questions about concrete equipment? Call Dick at: (503)283-2105 United Equipment Sales

REFERENCES
1.  ACI Committee 237, “Self-Consolidating Concrete (ACI 237R-07),” American Concrete Institute, Farmington Hills, MI, 2007, 30 pp
2. Field investigation of self-consolidating concrete in formwork
Self-consolidating concrete: Proceedings from the first International RILEM Conference (The International Union of Testing and Research Laboratories for Materials and Structures)
Concrete flow behavior testing for self-consolidated concrete

Concrete International magazine articles:
Flowing or Self-Consolidating Concrete
Field Investigation of Formwork Pressures Using Self-Consolidating Concrete
Comparison of Three Methods to Measure Formwork Pressure When Using SCC
Pressure of Self-Consolidating Concrete on Formwork
From Rheology of Fresh Concrete to Casting Processes

 

Feb 18

Hempcrete – the Wonder of the Concrete World

Hemp productionWith 10 states having passed laws allowing hemp to be grown in the past year (*1)  for research purposes and 11 more states that introduced hemp bills this year (*2), hemp seems to be making a major coming back from its glory days. And glory days they were.

 

 

 

Some interesting facts about hemp!
Did you now that

– Hemp farming dates as far back as 5000 years in China.
– For thousands of year over 90% of all ships’ sails and ropes were made out of hemp.
– Prior to 1820s, 80% of all textiles, clothes, drapes, fabrics and most paper for schoolbooks were made of hemp.
– During the 17th and 18th century, you could be put in jail if you had land and refused to grow hemp.
– Henry Ford’s first Model-T was designed to run on hemp gasoline and that the car’s body was made of hemp plastic (which was 10 times stronger than steel!).
– It was in fact America’s first cash crop that yielded over a billion dollar, until the 19th century. Hemp rope
– In 1916, the US Government anticipated that by 1940s, all paper would be made out of hemp, ending once and for all the need to cut trees.

So how did this wonder plant manage to disappear but be banned altogether?

It all started under Hoover’s presidency, when Dupont, the chemical tycoon realized that he could not build his chemical empire and grow his powerful financial and business interests as long as this plant continued to be the main cash crop in America. After all, it required no chemical in order to grow and thrive. So financial interests combined with buying political favors resulted in a massive disinformation campaign, associating hemp with marijuana (a Mexican import) and the creation of the Federal Bureau of Narcotics in 1930, followed by the Marijuana Tax Act in 1937 making hemp the “evil weed”!

SO HOW IS HEMPCRETE MADE?
Simply by taking the inside stem of the hemp plant and mix it with a heated lime base binder to create the building material. Sand and pozzolans or cement can also be added. In terms of finishing, all that is needed for hempcrete walls, is either lime or clay plaster for internal surfaces and lime render for external walls. Stone, timber or brick can also be used as finishing. Lime-based paint should also be used.

WHAT IS HEMPCRETE USED FOR?
Uses include drywall, exterior walls, flooring, roofing and more.
– six-inch layer of Hempcrete can be sprayed on external walls and between the ceiling rafters to make the house more energy efficient.
– Hemp is used for wall insulation. But even better, building hempcrete walls do not require any insulation as they form the wall and insulation in one layer.
– It is an ideal material for restoration of old buildings, to repair infill panels and add insulation to uneven aging walls.
– To build hemp drywalls.
–   Hemp bricks are sold under names such as: Hemcrete, Canobiote, Canosmose, and Isochanvre.

WHAT ARE SOME OF BENEFITS OF HEMPCRETE?

It is flame resistant, water-proof, mildew resistant and rot-proof as long as it’s above ground.

Its thermal qualities are amazing, keeping buildings cooler in the summer and warmer in the colder month. And as a result, could reduce our energy bills in homes by half. Think of the possibilities and the impact when buildings are known to be one of the largest source of greenhouse gases in the US!

Hempcrete has great acoustic properties and is known to absorb noise, making quieter homes on busy streets.

Hempcrete is a hygroscopic material. In other words, when used to builld exterior walls, hempcrete will absorb moisture without rotting or damaging the material. It will then naturally release it during warmer and dryer temperatures. This is ideal for hot, cold and humid regions of the world that struggle with mold damage. Hemp puts an end to this problem.

Hempcrete is one of the best material for people suffering from allergies as it contains no formaldehyde, latex, urethanes or VOCs and is known to clean the air and remove toxins.

Do you live in an earthquake prone region? Foundations made with hempcrete provides 3 times more resistance to earthquake than regular concrete! Unlike cement, known for its brittleness, hempcrete combines strength and flexibility.

Hempcrete is extremely strong. When the lime hardens, it eventually turns into rock and petrifies. This means that hempcrete walls will last thousands of years, instead of 40-100 years for regular concrete. They can also be completely recycled in the ground.

MOST ECO-FRIENDLY ALTERNATIVE:   Hempcrete is Carbon negative

As a tall and super fast growing plant (new plants grow in just a few months), the cultivation of hemp removes more carbon dioxide from the atmosphere (due to its very high cellulose content) than the production and application of hempcrete combined! It is estimated that during its growing phase, it can remove over 15 tons of carbon from the atmosphere. A 1,250 sq. ft hemp house could save about 20,000lbs of carbon and only require 2.5 acres of hemp to be cultivated!

Hempcrete uses the woody stem that was previously thought as waste! Being naturally pest resistant and weed suppressant, its cultivation requires no chemical fertilizers and insecticides. Even better, the simple fact of growing hemp will help deterring insects from the area. Because of its deep root system, hemp cultivation is known to break down pour soil.

Since lime doesn’t need to be heated as much as with regular concrete when it is mixed with hemp, the process uses a lot less energy. Made too much hempcrete? Just use as fertilizer.

ARE THERE ANY ISSUES WITH HEMPCRETE?

Learning curve: As with all new technologies, there is a certain learning curve for using hempcrete and hemp building products. The good news is that there is plenty of information online and case studies available. Time will say how building using hempcrete will live up to their promises in different climates over time.

Pricing: Hemp products may be more expensive at the moment but the advantages outweigh the costs in most cases. With a broader adoption, prices will go down and make it the products of choice for all new construction.

Maintenance: Because of its high breathability, hempcrete requires the use of lime based paint which is more expensive (3 coats are required to achieve the right finish).

As our ancestors discovered, hemp offers one of the most renewable resource for construction, it answers every builder and home owner’s needs. It is in fact nature’s gift to humanity and it is time we give it its proper place in our world.

FURTHER READING

  1. Building with hempcrete
  2. Watch a hemp house being built in this video: Bringing it Home  
  3. Hempcrete Could Change The Way We Build Everything

(*1)States that have passed hemp law: California, Colorado, Kentucky, Maine, Montana, North Dakota, Oregon, Vermont, Washington, and West Virginia
(*2)States that introduced hemp law this year: Hawaii, Indiana, Nebraska, New Jersey, New York, Oklahoma, South Carolina, Tennessee.

Jan 28

Polyaspartic Coating for Concrete

What if in the sea of concrete sealants available on the market today, there was a new type of product that answered just about every operator’s wish list for achieving stunning looking concrete surfaces time after time? Too good to be true? What’s the catch? Let’s see what some of the claims that have been made about polyaspartic sealers:

What are the main Benefits of polyaspartics?

– Can be applied at any temperature (-30°F to 140°F).
– Bond to any concrete surface as long as it is prepped properly.
– Very low viscosity material can even seal small cracks due to its high flexibility.
– Produce a high film build with a single coat reaching 8 mils.
– Rapid curing to full strength  (from 5 to 120 minutes depending on the formula used).
– No or Low VOCs (volatile organic compounds) because made with high solids content.
– Superior stain and corrosion resistance.
– Greater impact resistance than epoxy or urethane coating.
– UV stable means it will never turn yellow and is a UV protected layer to the underlying coats.

That’s a pretty impressive list by any account!

So what are polyaspartic sealers made with?

Basically a two-part a polymer coating material where a resin is mixed to a catalyst to create the curing reaction that hardens the material. It has been compared to epoxy and was first invented in the mid 1980’s by Texaco Chemical Company. The original formula has since been experimented and vastly improved with a myriad of variables.

What are they best used for?
Residential and commercial applications.

Indoor:
Garage floors, auto showrooms, warehouses because of their high resistance to stain, heavy traffic, abrasion and chemical corrosion. The fact that an entire garage floor can be completed in 5 hours (instead of 5 days for an epoxy floor) when using polyaspartic coating, makes it stand out from the competition. Quartz sands or vinyl flecks can even be added to the formula for a more decorative finish look. While the cost of material may be a little higher than epoxy, the time saving makes it a superior alternative.

Great for sealing concrete counter tops due to their ability to resist acidic materials like lemon, wine etc. (link to other article)

polyaspartic coatingOutdoor:
Bridges – when embedded reinforced steel in bridges are sealed with polyaspartic coating, the structure is protected from the corrosion caused by fresh or sea water. All concrete piles of the 7-mile San Mateo/Hayward bridge in California received a 3-coat application of polyaspartic polymer during its construction, providing UV protection and deterring barnacles from clinging to the structure.

Limitations & risks

– Insufficient surface preparation can lead to disastrous results.
– Polyaspartics are impermeable so new floors should be cured for 28 days or more before applying sealer. If the substrate is contaminated or moisture is found on the surface, the coating will stick to it rather than the surface!
– Surfaces that have been cleaned with acid etching will not work because it lowers the pH and can cause delaminations problems.
– Potlife of some products can be less than 20 and as a result not adequate for large jobs.
– Product’s low tolerance for mis-application and poor installation practices.
– Not appropriate for floors with high moisture vapor emission rates.
– Fail to properly prepare will yield costly failures and rework.

CONCLUSION:
As for all new technologies, there is a phase of trial and error and a definite learning curve that are required. The most important thing to remember is that polyaspartic sealers are not for all jobs. The appeal in finishing a flooring surface in a day shouldn’t outweigh the other factors to consider. The two main causes of adhesion failure are the underlying surface has not been adequately prepared and when moisture is found on the surface. As long as you follow the manufacturer’s instructions, you should end up with a stunning results.

Examples of polyaspartic products:
InstaDrive from Kamcrete
Rapid 1000 from Rapid Coating Systems
Roll On Rock from Versatile Building Products

Have questions about concrete finishing, concrete pumps or accessories, give us a call at: (503)283-2105.United Equipment Sales

 

 

Additional reading
Different types of polyurea
Polyaspartic floor coating uses
Buyer’s Guide to polyaspartics

 

 

Dec 20

2015 CONSTRUCTION OUTLOOK

As we are approaching the end of the year, it is good to look back on the year and plan for the year to come. On the macro level, we see that the US economy is slowly and finally stabilizing. It continues to have its share of fits and starts that are being reflected in the construction industry which is expected to grow to $9.4 trillion in 2015, according to Construction Perspectives and Oxford Economics, and total construction employment reaching up to 5.85 million. This constitutes a record since 2009 but we are still at 50% pre-bubble levels and might have to wait until 2017 to have fully recovered! So while things are headed in the right direction but we are far from out of the tunnel!

Here is the good news, with higher income and more jobs (3 million new jobs in 2014), demand for housing keeps increasing. It is estimated that there is 1 more million potential home buyers on the market today (younger buyers). Record low interest rates combined with lower down payments from Fanny and Freddie mortgages, lesser restrictions on credit conditions, a stronger job market means greater home buying power for Americans. As of Dec. 11 2014, an average 30-year, fixed-ratmortgage was 3.93 percent, down from 4.53 percent from January 2013! Stronger rental market has also boosted multifamily constructions to normal levels.

In 2015, new home sales are expected to increase 25 percent in the US, representing about 560,000 sales. This is still well below the 900,000 pre-bubble levels, but again, we are heading in the right direction. Housing starts should pick up 20% in 2015, for a total of 1.2 million, according to Kiplinger’s December economic outlook**

TOP HOUSING MARKETS FOR 2015
Here is Realtor.com top pick from their recently published 2015 Housing Forecast:

Dallas-Fort Worth-Arlington, Texas: ranked 1st in forecasted household growth over the next five years.
Houston-The Woodlands, Texas: ranked 3rd with 4% increase over the next five years.
Los Angeles-Long Beach, California: 4th place in potential household growth and a 4 percent increase over the next 5 years.
Washington, D.C.: ranks fifth. The sequester did deflate the housing market in 2013 and early 2014 but the situation is now corrected and a 10% increase in home sales is expected over the next 5 years.
Atlanta-Sandy Springs, Georgia: ranks seventh in forecasted household growth over the next five years with home sales are expected to rise by 11 percent.
Minneapolis-St.Paul-Bloomington, Minnesota is the second largest home-owning millenial households.
Denver-Aurora-Broomfield, Colorado is expected to see a 14% increase in home sales.
Des Moines-West Des Moines, Iowa
Phoenix-Mesa-Glendale, Arizona expects a 22 percent increase in new construction over the next 5 years.
San Jose-Sunnyvale-Santa Clara, California: Sustained employment and income growth makes this market outperform neighboring Bay area cities.

US Housing Starts

Courtesy of National Association of Home Builders

Top US states for Housing starts according to the National Association of Home Builders:

The South leads the pack with the following states:
Delaware, Maryland, District of Columbia, Virginia, West Virginia, North & South Carolina, Georgia, Florida, Kentucky.

Followed by West and the following states:
Montana, Idaho, Wyoming, Colorado, New Mexico, Arizona, Utah, Nevada, Washington, Oregon, California, Alaska, & Hawaii.

4 NEW TRENDS IN CONSTRUCTION :

  • Commercial lending on the increase:
    Following the financial crisis in 2008, banks proceeded with a complete lending freeze in 2009. A slight improvement was noticed in 2013 and 2014, leading to a jump in commercial lending and a record in construction starts*. This trend should continue and even increase in 2015.
  • Green from the get goEarth-Friendly-Icon
    What used to be seen as an expensive “nice to have” features for high end construction is now being incorporated at the design level, as part of the blueprint that includes sustainable building materials, renewable energy, optimized energy performance and cradle to cradle components (LEED v4) for new construction projects. Demand for green renovations in existing buildings will also continue to grow.
  • Mobile technology on the job
    Design firms, building contractors, project managers are ditching paper for tablets, laptops and smart phones on the job site to better plan, manage projects and overall productivity.
  • Demand for infrastructure repair
    Previously, demand for construction was mainly driven by the private sector, but recently, with more natural disasters and extreme weather conditions in our future, rebuilding and fixing existing infrastructure is taking a more prominent place in the US and around the world.

8 FASTEST GROWING CITIES IN THE US 

In addition to looking at housing starts, we also should take into consideration population growth provided by the U.S. Census Bureau population data (for July 1, 2012 through July 1, 2013) (measuring percentage population gain) and new construction for commercial and residential building. And the winners are:

Houston, TX (growing oil and gas industries) 2.6% gain
Austin, TX (fastest growing cities for the 4th year in a row) 2.5% gain
Phoenix, TX (construction industry jobs are up 5% year-over-year)
Raleigh, NC (Large tech companies, major universities, low unemployment rate) 2.2% gain.
Orlando, FL (booming tourism industry) 2% gain.
San Antonio, TX (oil industry) 1.9% gain.
Denver, CO (outdoor activities, growth in tourism, construction) 1.9% gain.
Nashville, TN (Music industry, healthcare companies, affordable cost of living) 1.8% gain.
Charlotte, NC (2nd largest banking center in the US after New York) 1.8% gain.
Oklahoma, OK (job growth in the oil industry) 1.7% gain.
Phoenix, AZ (growth in renewable energy, biomedical and aerospace) 1.6% gain.
Salt lake, UT (low 4% unemployment rate, growth in residential and commercial real estate, construction).

WHAT ABOUT EUROPE? 
With its aging population and low birth rate (1%), weaker economies (Spain, Greece, Portugal etc.) Europe isn’t a great prospect for construction and new housing in the coming years. There is one exception: Istanbul, Turkey, the frontier between Europe and Asia, is showing signs of both and economic growth.

TOP 10 FASTEST GROWING CITIES IN THE WORLD (Next decade growth)
NOTE: The data below is based on population projections from the United Nations and immediate need for rapid housing construction and infrastructure development. They do not cover megacities that have known massive expansion in the past 20 years (like Mumbai, Mexico City, Dhaka, Bangladesh). As in all cases of explosive urban growth, the road is paved with many obstacles such as government instability, natural disasters, poverty level etc.

10. Chittagong, Bangladesh with projected 80% growth from 2006 to 2020 (second largest city and commercial capital of Bangladesh with a booming commercial real estate industry and construction)
9. Dar Es Salaam, Tanzania with 82% growth from 2006 to 2020 (is the third fastest growing city in Africa after Bamako and Lagos and ninth in the world). Had major construction boom in the past few years.
8. Faridabad, India with 83% growth (residential growth, end-user driven market)
7. Lagos, Nigeria with 84% growth (following a building collapse from 2000 to 2010, rebuilding infrastructure, improving safety)
6. Bamako, Mali with 84% growth (improve Mali’s urban infrastructure, drainage projects, flood protection)
5. Kabul, Afghanistan with 91% growth (military and political instability are major factors affecting the rebuilding of the country)
4. Surat, India with 98% growth (Gujarat’s second-largest city, eighth largest city and ninth largest metropolitan area of India, first smart IT city in India)
3. Sana’a, Yemen with 98% growth (largest city in Yemen, massive rural immigration is forcing investment in underdeveloped infrastructure and municipal services)
2. Ghaziabad, India with 103% growth (infrastructure development, residential market growth offers affordable housing and mid- segment)
1. Beihai, China with 309% growth (higher demand in biggest cities continues to climb while demand in smaller cities continues to fall).

In addition to the above, there a few emerging powerhouse cities that act as strategic platforms for China and India with the rest of the world that should be mentioned. They are:

Chongqing, China: This city serves as connector for top interior cities like Shanghai, Hong Kong, Shenzen and Guangzhou. It is in the process of building a large transportation infrastructure (new plane, roads, rail connections…)

In India, Bangalore, Ahmedabad (100.000 new jobs this year) and Chenmai (highest per capital income in India) are becoming world centers for auto manufacturing, software and entertainment. New housing construction is on the rise as a result of a fast growing middle class, investments  from foreign companies, centers for higher education.

So whether in the US or abroad, the construction industry and new housing will continue to grow in the cities and regions mentioned above providing plenty of work and opportunities for this recovering industry.

Sources:

Commercial Construction Industry Outlook and Trends
*United States Construction Outlook
**Kiplinger’s Economic Outlook
New building permits from the US Census bureau

Nov 13

Fly Ash Concrete

Fly ash in concrete

FROM GREY TO GREENISH …

If you consider yourself a green person, you may think using fly ash, a by-product of burning coal, in your concrete mix rather sacro-saint! After all, coal plants are some of the biggest polluters and CO2 emitters.  In recent decades, in an attempt to minimize its environmental impact, the EPA forced coal-powered plants to trap particulate matter before it is released in the smokestacks, to properly capture and dispose coal ash, a.k.a. as fly ash, the residue found after smokestacks are cleaned. Disposal of fly ash is usually done by mixing it with water and placing it into open impoundments (that could be damaged by storms), storage ponds or buried in landfills that have been known to occasionally breach or leak as in the case of the December 2008 collapse at the Tennessee Valley Authority’s Kingston Fossil Plant, releasing 5.4 million cubic yards of coal fly ash into the Emory River! So how much are we reusing? Approximately 43-45% of all fly ash is being recycled today.

Electrical PoleWith 50% of all electricity in the US being generated by coal plants, one couldn’t begin to imagine the huge amount of fly ash produced by coal-powered plants daily. Capturing it and reusing it in a safe way would in fact prevent the inevitable spread of some of the heavy metals  it contains (depending on the coal bed makeup: arsenic, lead, chromium, mercury, dioxins etc.) in the atmosphere we breathe, the water we drink… So when the first attempts at substituting fly ash to Portland cement resulted in a concrete with greater strength and durability, what was once a worrisome problem looked like it could be turned into a solution for the environment and the construction industry. Recycling fly ash into concrete would not only reduce CO2 emissions but also neutralize the harmful effects of the known carcinogens it contains and the need to mine for new raw materials. Also called geopolymer concrete, this “green” concrete is cheaper to produce and is being widely adopted for all types of concrete applications.

2 TYPES OF FLY ASH
There are 2 classes and both can be used as a replacement for Portland cement or hydrated lime. They act as a filler providing contact points between larger aggregate particles in asphalt concrete mixes.

Class F: is made from burning anthracite and/or bituminous coal
Class C: is made from lignite or subbituminous coal

BENEFITS OF USING FLY ASH IN CONCRETE

Earth-Friendly-IconECO FRIENDLY?
The process of making cement is quite energy-intensive and could account for 5-8% of greenhouse gas emissions around the world. Factor in steady population growth and the number will continue to increase unless a massive adoption of greener alternatives happens. Fly ash concrete is one of them because of its abundant availability, cheap cost and the fact that it could reduce as much as 90% of CO2 emissions when considering the end to end process.

Green builders can gain points towards their LEED goals (Leadership in Energy and Environmental Design) if they can replace at least 40% of Portland cement with it. Bricks that are made with fly ash can even store CO2 from the atmosphere.

ALL AROUND BETTER CONCRETE
Fly ash is known to improve concrete’s workability, pumpability, chemical resistance, finish, strength, and durability. Fly ash particles are similar in size with Portland cement and as a result requires less water during the mixing stage. This means better surface finish, sharper edges in precast concrete. Its fine particles reduce bleeding and segregation and improve overall workability. This is especially helpful in extending working time in hot weather.

DECREASED PERMEABILITY:
Fly ash produces a concrete that is less porous than Portland cement. The pozzolanic effect of fly ash creates a denser product due to smaller pore sizes. It also reduces bleed channels and permeability in concrete.

Widely used in road projects, fly ash increases the stiffness of the asphalt, improving rutting resistance and mix durability.

EXAMPLES OF FLY ASH REUSE

In addition to replacing Portland cement, fly ash is being used in the following areas and the list keeps expanding:

  • Road construction: ideal self-compacting backfill material (as a replacement for compacted earth) for backfill, embankments, road sub base construction, mineral filler in asphaltic concrete, as a loose application on roads for ice control, in highway sound barriers…
  • Agriculture: fertilizer, soil amendment and stabilization.
  • Aggregate material substitute: for brick production replacing clay.
  • Dam construction: in roller compacted concrete dams.
  • Waste management: waste solidification and stabilization, conversion of sewage sludge into organic fertilizer or bio fuel.
  • Roofing material: tiles, granules.
  • Marine: pilings, artificial reefs
  • Binding agent: paints, undercoating.
    And much more

IN CONCLUSION

Only time will tell whether or not small amounts of heavy metals could leak from the concrete over time and if this new found durability is truly long lasting. Recent spills have prompted environmental groups to call for tougher regulations, so whether or not the EPA decide to classify it as hazardous  material remains to be seen. But until then and until coal powered plants are being phased out for greener alternatives, and the huge reserves of fly ash remains an environmental issue, the safe use of fly ash in concrete makes sense and should continue. 

United Equipment Sales

Sources:
Marc Boyer: How fly ash concrete works
Fly Ash on Wikipedia
Fly ash products
Fly ash suppliers

 

Aug 05

Architectural & Decorative Concrete

The concrete industry has come a long way and keeps reinventing itself to answer the needs of builders, architects and even decorators. With more and more home owners attracted to a greener and more sustainable lifestyle, we have seen, in more recent years, a new use of concrete, blending innovation and artistry to create truly unique surfaces for interior floors, patios and kitchen counters. Here are some of the coolest new possibilities:

Concrete Countertops in the kitchen:

Granite Counter top

When you think kitchen countertop, a few options usually come up. Depending on your budget, you can get high end and more expensive products like: polished granite, marble, quartz, soapstone, stainless steel and glass.  On the cheaper end and ideal for DIY afficionados, you have tile, wood and laminate. Other options that are becoming more popular are concrete and recycled concrete. The later one being one of the most eco-friendly choice that allows you to combine post-consumer products like glass, paper, composite and plastic with concrete for a truly unique finished product.

Plain concrete can be used in countertops, landscaping and customized with various textures and finishes (stain color). A really nice feature of concrete is its ability to be energy efficient. Whenever the temperature rises, the concrete traps the heat and releases it when the temperature cools down.

White Portland cement
To transform what may be viewed as boring cold grey concrete into bright, elegant aesthetic surfaces requires a combination of special ingredients, forms and finishing technique. The magical ingredient in this case is white Portland cement.  It comes plain or pigmented and is available in wide array of colors, from pastel to saturated colors. It can be used indoor or outdoor and has the same durability properties as grey cement but contains more metal oxides like iron and manganese, giving it its whiteness. White cement concrete is used in exposed architectural concrete, landscaping, building accents and more. It provides greater energy efficiency and safety because of its light color.

Some design ideas

Stone finishing

Concrete can be transformed to look like natural stone. To create this effect, you will need to cast the concrete in an integral color then apply multiple layers of acid stain to the surface until the desired result is obtained. TIP: Use the veins produced by the marbelizing effect to hide seams on your countertop.

Wood grained concrete texture

 

Create a wood-grained finish to any surface by applying a technique called “board forming”. To create this unique texture, you will need to cast the concrete in forms that have been previously lined with unfinished wood that will imprint the wood texture into the concrete surface. You can also create board lines by cutting straight lines with a saw after it is cast. Next is creating a realistic color using both integral color with topical stains.

To create a smooth and elegant look to your surface, you can polish or sand your concrete. It is recommended that the counter top be poured in one piece and not show any seam. To create the look of marble, you will need to use a titanium-white concrete mix that contains white silica sand. You can also hand sand the surface lightly for a less shiny and more natural look.

Exposed Aggregate Finish
This is where the use of post-consumer products like glass, stones, bricks, even shells can be recycled and added to concrete to make truly unique finished surface. There are 3-4 steps to create this type of finish: first you pour the concrete, then you insert pieces of material of your choice (broken glass, decorative stone, shells etc.) Once the concrete has set  you grind the surface to expose the aggregate. Finish with a high gloss sealer to protect your newly created surface.
TIP: for spectacular results it is best to select pieces that will create the most contrast with the concrete color.

If you are looking for a good deal on a concrete pump or want to make sure you have the right pump for the job, give us a call at: (503)283-2105 or visit us at: www.Unitedequipmentsales.com

Related reading
Milestones in the history of concrete construction
Photos of concrete counter tops
Applications for architectural concrete