PROJECT PROFILE – Twin Hills Country Club, Oklahoma City, OK
This renovation of an iconic country club put AccuLevel® G-40 to the test.
PROJECT OVERVIEW
Twin Hills Country Club had a real problem. Fortunately, AccuLevel® G-40 was the perfect solution. The golf course in Oklahoma City, OK was in the middle of a major renovation and addition to their iconic clubhouse.
PROJECT DETAILS
The history of Twin Hills dates back to 1920 and has hosted several prestigious tournaments over the years including the PGA Championship, with players including Johnny Revolta, Arnold Palmer, and Gene Sarazen.
After removing the existing floor, they facing a huge challenge with the subfloor. The previous design used cinder block slabs, a common practice 80 years ago, but it left a big problem. How do you get a level floor when that subfloor looks like a gravel road. And just capping it with concrete was not a solution due to needing to remove the supports.
SOLUTION
Bill Ritchie and John Lowry of Gypsum Floors of AR/OK, Inc. were called to see if they could help. After a review of the structure, they recommended AccuLevel G-40. “I’ve poured it as thin as half an inch to as much as 2 inches” said Ritchie. “We have used it for several jobs and we always get excellent results.”
With the seasoned crew from Gypsum Floors of AR/OK onsite, the project took less than a day to complete. Working around the obvious challenges of the sublfloor, the end result was a remodel and the new addition now have a smooth flat surface that is as hard as a rock.
“The client was very happy” Ritchie said, “they got a floor better than what they hoped for.”
To view the case study – click here
Plenty of reason for optimism, industry stakeholders say
Aggregate demand has not been a problem of late for the industry, and expectations are high for healthy demand in 2022.
Optimistic.
That’s the word aggregate industry stakeholders use to describe their outlooks for 2022. But while the year promises no shortage of projects, the industry finds itself playing a supply-and-demand game: keeping up with the increased aggregate demand while navigating shortages and delays in the supply chain.
Boosted demand
Producers, equipment manufacturers and dealers tend to agree demand is up across the board. This is due, in part, to the Infrastructure Investment & Jobs Act (IIJA), which passed with bipartisan support in November.
Karen Hubacz, president and CEO of Massachusetts-based Bond Construction Corp., says the infrastructure bill’s components – namely industry exemptions, the ROCKS Act and enhanced permit streamlining – provide producers a much-needed confidence boost.
“It’s vitally important,” Hubacz says. “It’s really like an insurance policy for us in that we feel much more confident to put money into ourselves, specifically to maybe do plant improvements – things that cost a lot of money – because we know we’re going to invest this money in ourselves. But it’ll pay for itself sooner than later based on what we anticipate happening.”
IIJA’s passage was an added 2022 bonus for Unified Screening & Crushing, but the company was already planning for increased demand without it.
“There’s a lot of building, a lot of construction projects going on,” says Andrew Lentsch, COO of Unified. “So even without the infrastructure bill, I think there was still going to be an increase in demand. But, hopefully, that drives it even more.”
Similarly, The McLean Co., an Ohio equipment dealer, expects 2022 growth. Chris Reiser, the company’s crushing and screening specialist, describes his outlook as “cautiously optimistic” because of IIJA funds rolling out this year and his customers’ projections.
“You can forecast all you want on your own,” Reiser says. “You can say: ‘OK, we had 10 percent growth last year, let’s shoot for 15 percent this year.’ But at the end of the day, you’re only going to supply what’s needed. So if everybody you would otherwise sell to is growing, that’s a pretty good outlook for yourself as a business.”
Still, each year presents challenges. While increased demand and additional funding bodes well for industry stakeholders, supply shortages and delays aren’t going away anytime soon.
As of January 2022, Hubacz, Lentsch and Reiser each saw varying lead times for equipment, supplies and parts.
“Some are days,” Hubacz says. “Some are weeks. Some are months and months. Or, you get the ‘sorry, we just don’t know.’”
Hubacz adds that not knowing when parts will arrive can impact when projects get done.
“Even now, we can barely keep up with demand,” Hubacz says. “And then there’s a breakdown. We find out with the breakdown all we need is a simple sensor to fix the issue. You call your dealer [and] your dealer can’t tell you where one even is or when we will get it to you. So it is a giant problem.”
The McLean Co. supplies equipment coming from overseas. While its manufacturers have done a good job of getting equipment over as quickly as possible, Reiser says equipment sometimes gets stuck at backed-up shipping ports. It’s an issue that’s outside of a dealer’s or manufacturer’s control.
“So much of it depends on what these other countries are doing and what our port looks like,” Reiser says. “You could have a machine that you ordered six, eight months ago that’s finally coming in, but it might sit at [the] port for two to four weeks.”
Companies are also cautiously watching rising costs as 2022 unfolds. For Bond Construction, fuel prices are a factor to follow closely this year.
“The cost of doing business is on the rise,” Hubacz says. “This is mainly due to the elevated energy costs associated with gasoline and diesel. Everything from our aggregate production to our equipment needs are transported via trucks, plus all the different oil-based products we utilize every day. We’re all going to need to look at our bottom lines and make adjustments as needed.”
Unified Screening & Crushing, meanwhile, is hoping to see steel prices begin to level out at some point this year.
“Hopefully, the costs stabilize in the next 12 months,” Lentsch says. “There’s been quite a bit of increases over the last year to year and a half.”
Proving resilient
The concerns Hubacz, Lentsch and Reiser share are, of course, not new. These three and other industry leaders have been navigating the muddled supply chain and rising costs for the better part of the last two years.
Most industry leaders at least agree 2020 and 2021 were, all things considered, better years than expected for the aggregate industry. In fact, Reiser says he’s already seeing minor signs of improvement with supply delays versus 2021.
“I don’t think it’s anything really different than it has been, at least last year, as far as delays go,” he says. “I don’t think anything’s more delayed. If anything, we’re probably less delayed on our side of things.”
The year ahead is promising, Hubacz, Lentsch and Reiser say, with funds from the infrastructure bill, the return of large trade shows and an increased number of projects. And there’s no doubt among stakeholders that the industry is primed for another year of success.
“The demand for aggregates is up,” Hubacz says. “Pricing for aggregates is holding steady and even improving. These two factors together will give producers a solid foundation to invest in their companies, which will be great for the whole industry.”
To view the original article – click here
How Climate Affects Concrete – Hot Weather, Cold Weather, and Wind
Know what your concrete will likely do when the weather starts to get too hot, too cold, and/or too windy.
While working with concrete may come as second nature to many contractors, it is one of the trickiest substances to work with due to how quickly it can change when exposed to different temperatures, humidity, and wind rates. Ideal conditions for concrete are few and far between.
According to the ACI, concrete may be affected by, “…one or a combination of the following conditions that tends to impair the quality of freshly mixed or hardened concrete by accelerating the rate of moisture loss and rate of cement hydration, or otherwise causing detrimental results: high ambient temperature; high concrete temperature; low relative humidity; and high wind speed.” Under fair weather conditions, concrete can take anywhere from 8 to 48 hours to set properly. While concrete can reach its full strength in as little time as a week, it also takes nearly a month for it to cure properly.
However, anyone who has worked in construction before knows that weather conditions are seldom ideal.
While working with concrete may come as second nature to many contractors, it is one of the trickiest substances to work with due to how quickly it can change when exposed to different temperatures, humidity, and wind rates. The American Concrete Institute’s (ACI) technical publications are an excellent resource that provide insights regarding the plethora of effects of environmental factors on concrete. The ACI covers a variety of subtopics, ranging from extreme temperatures, humidity levels, wind velocity, natural disasters, saltwater, and freshwater’s effects on concrete in order to give contractors and concrete industry professionals accurate and up-to-date information.
Heat
The ACI’s (305.1 – 14 Hot Weather Concreting) specifications for setting and mixing concrete in hot weather suggests contractors should try to limit the maximum concrete temperature to 95º F. Contractors should ideally aim to work with, or pour, concrete when it is anywhere from 50-60º F. Under fair weather conditions, concrete can take anywhere from 8 to 48 hours to set properly. While concrete can reach its full strength in as little time as a week, it also takes nearly a month for it to cure properly.
However, anyone who has worked in construction before knows that weather conditions are seldom ideal, which is why contractors must have a firm understanding of the effects of hot weather on concrete structures and how to use weather to their advantage.
For example, concrete is known to set quicker in hot weather when compared to cold weather. This is because moisture found in freshly poured concrete evaporates at a quicker rate in hot weather and subsequently allows for a faster setting time.
Due to the rapid evaporation of moisture, concrete that is poured during warm weather conditions is also more likely to experience cracks. Concrete will also be prone to more cracks if it is poured in a location where the weather cools down quickly during the night. Because of these effects, concrete that is poured and cured in 75º F weather will likely outperform concrete that is poured and cured in 100º F weather. Simply put, timing and background knowledge are absolutely crucial when it comes to working with concrete in warm weather.
Cold
Cold weather, according to the ACI 306 – “Guide to Cold Weather Concreting”, is defined as three continuous days of low temperatures, specifically below 40º F. Additionally, the ACI also considers air temperatures below 50º F for more than 12 hours as “cold weather.”
Unlike working with concrete in hot weather, where certain warm temperatures can be used to a contractor’s advantage, colder temperatures can be detrimental to newly poured concrete.
When a concrete powder is mixed with water, an immediate chemical reaction will occur which results in an internal crystallization of the concrete. These crystals make it possible for concrete to withstand additional pressure that may be caused by frozen water molecules within the concrete.
Crystals will continue to grow for an extended period of time, even in cold weather. However, if temperatures drop below 15º they will no longer grow and the concrete will not cure at its full compressive strength.
Under ideal weather conditions, concrete can attain a minimum compressive strength of roughly 500 lbs. per square inch in as little as 24 hours. This is much harder to achieve in colder climates, so contractors have learned industry tricks to “fool” the concrete into thinking it’s in warmer conditions so it will ultimately cure faster.
The ultimate contractor rule when working with concrete in cold weather: Never pour concrete directly onto frozen or thawed ground space. The frozen ground will actually settle as it thaws. Because of this, concrete that is poured in very cold temperatures could also be susceptible to cracking, similar to working with concrete in warmer climates.
Wind
The ACI also states that wind velocity can affect freshly poured concrete by allowing too much water or moisture to evaporate from the concrete’s surface at a fast rate. In fact, the ACI technically classifies high wind velocity under hot weather due to the similar excessive loss of moisture concrete can experience when poured in warmer temperatures.
When concrete is poured during extremely windy weather, the rapid velocity of air will only contribute to excess moisture evaporating from the slab of concrete. Because of this, the abrasion resistance and curing condition of concrete will subsequently suffer.
Colder winds can produce what’s called a “wind chill,” which can strip excess heat from concrete. Additionally, plastic shrinkage cracking can occur when the surface of concrete dries before it has fully cured. To combat wind chill, it isn’t uncommon for contractors to turn to heaters to aid the curing process. Contractors can also use sealers to protect concrete from climates below 50º F.
Concrete is a delicate material. Unbeknownst to many people, it is not only affected by extreme temperatures, but also by humidity levels, as well as the velocity and intensity of the wind. Working with concrete demands skill and patience. It requires both the expertise of those working with concrete, as well as the cooperation of environmental factors in order to produce a smooth, strong, properly cured structure.
To view the original article – click here
Concrete and cement industries brace for demand boom
$1 trillion infrastructure plan looks to create increased demand.
Concrete is the foundation of just about everything. It’s used to construct buildings, highways, bridges, roads and more.
During the Covid-19 pandemic, concrete fell victim to the same phenomena impacting other essential materials and goods: snarled supply chains and labor shortages. And demand for concrete — and its essential ingredient, cement — appears to have only increased, after the Senate passed the $1 trillion infrastructure package to upgrade America’s roads, bridges and tunnels.
“In the short-term, we continue to have the supply chain difficulties, particularly in certain markets, and so prices are rising,” Anirban Basu, chief economist for the national construction industry trade association Associated Builders and Contractors, told CNBC. “So right now, apparently, supply is not rising up to meet demand.”
The industry also faces labor shortages of skilled workers and truck drivers. And the recent housing boom means more demand for concrete and cement, putting more pressure on the industry to increase capacity.
On top of all of this, there’s also a push to reduce the amount of carbon emissions that come from the industry. A study published by the National Academy of Sciences in 2019 estimates that global cement production accounts for 8% of global carbon emissions, making it the largest single industrial emitter of carbon dioxide.
Watch the video
to learn more about the cement-concrete supply chain and whether the U.S. industry can handle the coming demand from the new $1 trillion infrastructure spending plan.
Here is a link to a video that does a great job explaining the current and forecast demand:
To view the original article – click here
Concrete Technology 2021
Greener Every Year and 35% Stronger
In our era of “carbon neutral” construction materials and green energy trends, the term “green concrete” has evolved to describe an environmentally friendly construction material.
The term “green concrete”, not so many decades ago, used to describe the condition of freshly poured ready mix concrete in construction projects or precast concrete products that required more curing time to achieve its full average 3,000 psi strength. The term “green” as applied to concrete was all about quality control.
Now, in our era of “carbon neutral” construction materials and green energy trends, the term “green concrete” has evolved to describe an environmentally friendly construction material.
Recycling and Concrete
Concrete is the most durable construction material in the world, and like the concrete used by the Egyptians to build the pyramids, an incredible 5,000-year lifespan for concrete structures isn’t unusual. But with the ever-changing demands of human civilization, the demolition of old obsolete concrete buildings and structures is inevitable.
But what can be done to dispose of the concrete rubble, a construction material with such incredible resilience to the elements that it’s not going to break down naturally in landfills any time soon? The answer is simple. Use the old concrete to make the aggregates for new concrete.
Fortunately, the crushing characteristics of hardened concrete are nearly equivalent to natural rock. That means that the original quality of the recycled material isn’t a factor, except for the poorest quality original concrete. As an aggregate for new concrete, the recycled rubble actually has advantages. Since all the original aggregate components are there as well as the existing hydrated cement paste, recycled concrete aggregates add more to enhance binding and strength characteristics than virgin crushed rock and sand alone.
With over 70% of the world’s population living in structures that contain concrete, the most natural disaster-resistant building material available, only one other substance on the planet is consumed more by human society. That substance is water.
Under increasing environmental pressures, diverting concrete waste from landfills is another top priority for the industry.
New Research
In the US more than 55,000 miles of highway are paved with concrete. With such widespread use, scientists are constantly looking for innovative ways to make concrete even more resilient by increasing strength and heat resistance with new additives and aggregate enhancements.
Now scientists from Australia’s RMIT University may have come up with a win/win solution in the search for better concrete construction materials with a new recycled concrete aggregate that’s a superior choice for paving those 55,000 miles of highway.
In his informative January 2021 article at New Atlas Nick Lavars reports on how RMIT research has led to the addition of recycled rubber tires and concrete demolition rubble in the traditional time-proven concrete formula of portland cement, sand, crushed rock, and water. First developed for paving, the RMIT team is now moving on to develop the innovative recycled concrete formula for precast concrete products.
Arcosa Specialty Materials provides Gypsum Dihydrate and Gypsum Anhydrite to the largest cement manufactures in the nation. Our sister company, Arcosa Aggregates, has concrete recycling facilities.
To view the original article – click here