Things to Keep in Mind When Pouring Concrete in Extreme Heat

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Concrete FinishingAlthough cold temperatures are typically a greater obstacle when working with concrete, hot summer days can present some unique challenges as well. To understand how extreme heat affects freshly-poured concrete, it’s important to first have a clear understanding of how the concrete-setting process works.

Concrete sets via an exothermic reaction called hydration.

When concrete hydrates, it absorbs moisture and forms solid crystals around the aggregate particles in the mix. The process of hydration is slowed by cold temperatures and accelerated by heat. On especially hot days when crystallization happens more quickly, the crystals have less time to strengthen before the hydration process is complete. Evaporation can also compromise the strength of the concrete’s surface layer. This, in turn, can make the concrete more susceptible to cracking.

The good news is, there are a few strategies you can employ to help concrete retain moisture on hot days and ensure that the finished product is as strong as possible.

  • When pouring concrete in temperatures above 85°F, it’s a good idea to use a concrete mix with a higher volume of coarse aggregate particles. This can prevent the concrete from shrinking as it hydrates.
  • If possible, pour concrete early in the morning before the temperature peaks.
  • Spray cool water on the side forms and subgrade prior to pouring concrete slabs.
  • Use tarps or other sunshades to keep paved surfaces cool and prevent evaporation while the concrete sets.
  • Make sure you have enough help to mix, pour and finish the concrete without interruptions in between each step.

At Bergen Mobile Concrete, our metered mobile mixers are designed to provide a consistent, quality product that can be mixed to your exact specifications. Best of all, you’ll never have to pay for more than what you use! Just give us a call to schedule your concrete delivery today.

The US Army is 3D Printing Concrete Structures

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3D PrinterAdditive manufacturing processes—also known as 3D printing—are being used to make everything from medical devices to engine components, and now the U.S. Army is even using employing a similar technique to build concrete structures.

The U.S. Army Corps of Engineers has devised a system that allows them to create lightweight concrete structures quickly with a massive 3D printer. Once the technique is perfected, Army officials expect that they will be able to build temporary structures in a fraction of the time it currently takes to build using conventional methods.

It’s probably no surprise that 3D printing concrete structures is no easy feat.

Normal concrete–which contains a mix of aggregates like crushed stone, sand, gravel, and more–tends to clog printing machinery and cause equipment failures. To overcome this issue, the Army created its own concrete mix with sand, fly ash, silica fume, clay, a liquid admixture and water. This concrete mix is then paired with mesh layers to build strong, durable structures.

Army officials are optimistic that they will find a variety of practical applications for its new concrete and 3D printing process. These include building concrete barriers, barracks, training facilities and more in areas with limited resources. In the future, businesses in the civilian sector may even adopt similar additive manufacturing techniques to build concrete structures in record time as well.

Need a hand with your next concrete paving or construction project? Our concrete buggies and metered mobile mixers are designed to make concrete work easy and efficient. Give us a call or contact us online today to learn more.

Graphene Could Make Concrete Stronger, More Eco Friendly

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GrapheneRecent advances in nanoengineering have allowed scientists at the University of Exeter to develop an innovative new technique that incorporates graphene into conventional concrete production. The graphene-infused concrete is reportedly twice as strong and four times more water resistant than traditional concrete mixes. It also reduces the amount of materials needed to make concrete by about 50 percent, which could significantly reduce the carbon footprint of large-scale construction projects.

So what makes this experimental concrete so strong and durable?

Graphene is an emerging “supermaterial” with a wide array of industrial applications, many of which are only just beginning to be realized. It consists of a single layer of carbon atoms bonded together in a pattern of hexagons resembling a honeycomb. This unique atomic structure makes graphene the strongest material in the world. It’s also so thin that it’s technically classified as a two-dimensional material.

The researchers at the University of Exeter were able to incorporate this remarkable material into concrete mix by suspending it in water. The end result was a graphene-infused concrete that is low cost and compatible with current manufacturing requirements.

“This ground-breaking research is important as it can be applied to large-scale manufacturing and construction. The industry has to be modernized by incorporating not only off-site manufacturing, but innovative new materials as well,” said lead study author Dimitar Dimov in his comments.

Thanks to the efforts of Dimov and his team, graphene could make the concrete of the future even stronger, more sustainable and more water resistant than modern concrete mixes.

Researchers Use Fungus to Create Self-Healing Concrete

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Crack in Concrete DrivewayDo you have an old concrete driveway that’s starting to crack from years and wear and tear? At this point, you might be thinking about tearing it up and repaving it with fresh concrete.

But what if we told you a group of scientists is developing a new “self-healing” concrete that could stop small cracks from becoming huge fissures?

Recently, researchers from New York’s Binghamton University teamed up with Ning Zhang of Rutgers University to create a new kind of concrete that uses fungus to repair itself. By incorporating the fungus Trichoderma reesei into their concrete mix, the researchers were able to create paved surfaces that automatically re-seal themselves as small cracks develop.

The fungal spores lay dormant at first, but as soon as micro-cracks start to form in the concrete, the spores spring into action by mixing with water and oxygen to create calcium carbonate, a hard chemical compound that seals these tiny cracks before they become any larger.

The researchers are still perfecting their product, so you won’t be able to take advantage of it just yet. But at some point in the not-so-distant future, you might be able to repave your driveway or sidewalk with a new type of concrete that is extremely resistant to cracking. Who would’ve thought that a fungus could make concrete even more durable than it already is?

Ready to revitalize that crumbling old driveway? Our mobile mixers and buggy trucks make it easy and affordable to repave concrete surfaces such as patios, driveways and more. Give us a call to schedule your appointment today!

Researchers Develop New Wear-Resistant Concrete Treatment

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Researchers Develop New Wear-Resistant Concrete TreatmentConcrete is a famously durable building and paving material, but even the most robust concrete mix can be damaged by prolonged exposure to heavy wind and rain. Harsh environmental conditions can accelerate concrete deterioration, reducing the effective service life of concrete structures and paved surfaces.

Engineers have been experimenting with ways to weatherproof concrete for decades.

Most of these weatherproofing techniques have involved applying protective materials to the finished concrete, but these treatments tend to be highly toxic and bad for the local environment. Recently, however, a group of researchers at Brunel University London developed a creative new way to protect concrete from wind and rain without utilizing toxic chemicals.

This technique utilizes a crystallizing admixture in conjunction with a wax-based curing agent. First, the crystallizing admixture is applied to fresh, uncured concrete. Then, after about an hour, the curing agent is applied to the concrete as well.

“The material works by absorbing water that exists within the concrete to form crystals,” said head researcher Mazen Al-Kheteen in an interview. “Whenever the crystals are formed they line the pores of the concrete, allowing it to breath. It also works on repelling water that tries to penetrate through.”

Al-Kheteen and his team hope that their environmentally-friendly weatherproofing treatment will save companies valuable time and money by reducing the amount of maintenance that is required to maximize the lifespan of concrete structures. The treatment could be particularly cost-effective because it can be applied on both wet and dry concrete surfaces “without affecting its performance.”

The research team’s weatherproofing treatment is still in development, but preliminary results have been very promising. Before too long, it could become a readily available option for concrete projects in areas prone to harsh weather conditions.

MIT Students Strengthen Concrete With Recycled Plastic

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MIT Students Strengthen Concrete with Recycled PlasticConcrete mixtures have evolved quite a bit over the course of the last several thousand years. Whereas the ancient Romans added volcanic ash their concrete to allow it to set underwater, modern concrete often features chemical admixtures to control its hardening rate and tensile strength. Engineers are always looking for ways to make stronger, more durable concrete mixtures, and a team of MIT undergrads may have just made a surprising new breakthrough.

The students set out to make industrial concrete stronger and more-environmentally friendly by experimenting with different additives. In their preliminary research, the students found that some types of plastic become stronger when exposed to gamma radiation. This gave them an idea: Why not use plastic bottles from the local recycling center to create a strengthening agent for their concrete mixture?

After developing their hypothesis, the students went to work gathering recycled plastic bottles and crushing them into fine particles with a ball mill and hand tools. Then, they used a cobalt-60 irradiator (which is often used to decontaminate food in commercial settings) to bombard the crushed plastic with gamma rays. After adding the irradiated plastic to a standard concrete mixture, the students ran a series of tests and found that the concrete was 15 percent stronger than their control samples.

“We know that the plastic makes it denser and forms particular crystalline structures in the material that make the final concrete stronger,” said assistant professor Michael Short in an interview.

Now, the team of students hopes to refine their technique and explore ways to make the plastic-infused concrete marketable to construction companies.  They’re currently working on a proposal to the National Science Foundation for additional funding. With continued research and development, the students may be able to create an innovative new type of exceptionally strong, eco-friendly cement.

Swiss Researchers Develop Ultra-Thin Concrete Roof Design

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Swiss Researchers Develop Ultra-Thin Concrete Roof DesignConcrete is one of the oldest building materials in the world, and yet engineers are still finding creative new ways to incorporate concrete into their industrial designs. At ETH Zurich in Switzerland, for example, one group of researchers recently built a prototype roof design using a curved concrete that’s just 5 cm thick on average.

As you might expect, creating an ultra-thin concrete roof with dramatic postmodern curves is easier said than done.

The project was made possible thanks to advanced computer algorithms that were used to distribute forces evenly across the roof’s curves and contours. Instead of using a foam or wooden mold, the researchers applied the concrete to a flexible net of steel cables which was stretched and bent into the desired shape.  The roof also required a carefully-controlled concrete mix that could be sprayed on in an application process developed specifically for this project.

The end result is an eye-catching concrete roof that seems to defy the laws of physics.

At its thinnest point, the concrete is just 3 cm thick. Next year, the final version of the roof will be installed on an eco-friendly apartment complex in Zurich. The roof will also include a network of energy-efficient heating and cooling coils sandwiched between two layers of the ultra-thin concrete, and a photovoltaic solar film on top. Although the prototype design took about six months to get right, the researchers are hoping to build the final version in just eight to 10 weeks.  It’s an ambitious plan that could help the research team land more contracts for their thin concrete designs in the future.

Stay tuned for more updates on the latest developments in concrete design and construction from the folks at Bergen Mobile Concrete!

Yellowstone Installs New Walkways Made of “Thirsty” Concrete

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Yellowstone Installs New Walkways Made of “Thirsty” ConcreteMost people visit Yellowstone National Park to take in the natural scenery and get away from the usual hustle and bustle of tech-filled lives. But as it turns out, Yellowstone is employing an interesting new concrete technology which could soon become a popular paving method elsewhere as well.

Yellowstone officials recently installed a 4,000-square-foot walkway in the park made of a unique new type of concrete called Flexi-Pave, according to Business Insider. Flexi-Pave consists of a mixture of tires, stone and a proprietary binder, and one square foot of the concrete is capable of absorbing an astounding 3,000 gallons of water per hour. This comes in handy in Yellowstone, since the park contains about 66 percent of all the geysers on the planet. The park’s new “thirsty” pathway absorbs water and distributes it back into aquifers before it can mix with local contaminates, which is a really big benefit in the ecologically-sensitive environment of Yellowstone.

Yellowstone might be the most notable example of Flexi-Pave’s applications, but it’s far from the first time the concrete has been used as a paving material. According to Kevin Bagnall, founder and CEO of the company that created Flexi-Pave, at least 200 cities throughout the US have begun using the eco-friendly concrete in their own paving projects.

At Bergen Mobile Concrete, we’re constantly monitoring the latest trends in construction in an effort to better serve our customers. Need a hand with your next concrete paving project? Give us a call at (201) 979-7550 today to get started!

Researchers Solve Mystery Behind Ancient Roman Concrete

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Researchers Solve Mystery Behind Ancient Roman ConcreteModern cement-based concrete might be pretty durable and long lasting, but it’s got nothing on the concrete used to build piers, sea walls and harbors in ancient Rome. Despite being partially submerged in corrosive saltwater for more than two thousand years, many of these structures remain standing to this day. Scientists have long wondered why the Romans’ blend of volcanic ash, rocks and lime has been able to stand the test of time, and after a new round of analysis they finally have their answer.

The researchers used a combination of X-rays, spectroscopy and electron microscope analysis to study the distribution of elements in samples of the ancient concrete. After taking a closer look at the concrete, the researchers were able to identify a rare mineral called aluminous tobermorite that had formed powerful interlocking crystals throughout the concrete mix. As they grew, these crystals caused the concrete to get stronger with time, allowing it to retain its structural integrity for thousands of years.

So what caused the strengthening  tobermorite crystals to form?

In fact, it was prolonged exposure to seawater. Rather than corroding the Roman concrete, the seawater triggered a chemical reaction in the lime which caused the crystals to grow and spread through the concrete. Simply by chance, the unique combination of volcanic ash, lime and seawater caused the ancient Roman concrete to grow stronger with time.

“Contrary to the principles of modern cement-based concrete, the Romans created a rock-like concrete that thrives in open chemical exchange with seawater,” explained lead study author Marie Jackson in an interview with BBC.

Now, the researchers are looking for ways to implement the unique chemical properties of ancient Roman concrete into new structures such as the Swansea Bay Tidal Lagoon in Wales. This may be easier said than done, however, as the type of volcanic rock present in Roman concrete is hard to come by in many parts of the world. The Romans were lucky enough to be situated in a place where all the elements for their super-strong concrete just happened to be readily available.

Researchers are 3D Printing a Reinforced Concrete Bridge

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Researchers are 3D Printing a Reinforced Concrete Bridge3D printers are useful for more than just making small plastic parts. Recently, a team of researchers at the Eindhoven University of Technology in the Netherlands began 3D printing reinforced concrete components for a cycling bridge in an effort to test out new applications for 3D printing technologies.

In fact, this isn’t the first time engineers have 3D printed a concrete structure. Last year, the city of Madrid unveiled a 3D-printed concrete pedestrian bridge that was hailed as an engineering milestone. The cycling bridge in the Netherlands will take things a step further, however, by incorporating steel reinforcement cables into the design.

These steel cables will also be printed in conjunction with the concrete components. This process will provide the bridge with added stability, because the steel and concrete parts will be “pre-stressed” together. The bridge will also require far less concrete than a conventional bridge, because 3D-printing is less resource-intensive than pouring concrete into a mold.

As a proof of concept for their design, the researchers built a 1:2 scale model of the bridge that was able to hold a load of more than 4,400 pounds. The next step is to complete the full-scale construction and put the 3D-printed bridge to work.

It’s not clear whether this bridge-building technique could be adapted to accommodate vehicle traffic, but with additional research and development 3D-printed structures could become much stronger in the future. Someday, architects may even be able to design full-blown buildings with 3D-printed concrete.

Need a load of concrete for your next big project? Our all-wheel-drive buggy can bring the concrete right to you. Give us a call at (201) 797-7550 today to get started.