The U.S. multifamily construction market remains strong
2021 multifamily housing outlook: Dallas, Miami, D.C., will lead apartment completions
In its latest outlook report for the multifamily rental market, Yardi Matrix outlined several reasons for hope for a solid recovery for the multifamily housing sector in 2021, especially during the second half of the year.
While multifamily owners, developers, and property managers collectively braced for severe drops in rent growth, construction starts, project completions, and availability of capital amid the COVID-19 pandemic, the drastic declines never materialized.
Rent growth did take a step back in select markets, especially in “high-cost gateway” metros like San Jose (-13.7%) and San Francisco (-9.4%), as renters continued to leave pricey urban neighborhoods for less-dense, cheaper suburban areas.
But on the flip side, “many tertiary and tech hub markets have benefited from migration out of the gateways,” wrote the authors of the Yardi Matrix report. Secondary and tech markets like the Inland Empire, Sacramento, Tampa, and Las Vegas all saw solid rent growth in 2020.
Multifamily construction pipeline for 2021
Other than the temporary shutdowns of work sites during the pandemic, construction work on multifamily housing developments continued to hum along through 2020 and into 2021. In all, 285,000 multifamily units were delivered throughout U.S. markets in 2020, down about 7% from 2019, but not nearly as severe a drop as many had predicte
According to Yardi Matrix, the multifamily sector has a “robust pipeline” of new projects, with some 765,000 units in some stage of construction as of early 2021.
This “should keep deliveries above that 300,000 mark for the next few years.” The firm projects 327,718 units will be delivered in 2021.
Here are the top 25 multifamily markets for 2021 (total number of construction completions, % growth in completions YOY):
- Dallas: 22,909 completions (+12.1% YOY)
- Miami: 16,262 (+66.3%)
- Washington, D.C.: 14,541 (+50.5%)
- Houston: 11,500 (-3.1%)
- Los Angeles: 11,296 (+16.5%)
- Atlanta: 10,939 (+9.7%)
- Austin: 10,301 (-10.0%)
- Seattle: 9,816 (+29.9%)
- Phoenix: 9,334 (+13.6%)
- Denver: 8,653 (-29.7%)
- Boston: 8,449 (+20.8%)
- Chicago: 7,797 (+0.8%)
- New York City: 7,335 (+24.2%)
- San Francisco: 7,166 (+64.8%)
- Twin Cities: 6,760 (+4.9%)
- Charlotte: 6,692 (+55.3%)
- Orlando: 6,662 (+21.5%)
- Philadelphia: 6,071 (+27.7%)
- Nashville: 5,457 (+41.1%)
- Tampa–St. Petersburg: 5,103 (+20.1%)
- San Antonio: 4,960 (-6.5%)
- New Jersey–Northern: 4,955 (+29.9%)
- Salt Lake City: 4,633 (-0.6%)
- Louisville: 4,484 (+215.6%)
- White Plains: 4,464 (+199.6%)
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Gypsum an Important Source of Sulfur
Sulfur important in plant growth.
Long taken for granted as supplied by the soil and atmosphere, sulfur is slowly rising as a yield-limiting nutrient in crops across the US.
Ken Ihlenfeld is certainly finding this to be true. The West Bend, WI, producer farms 2,500 acres including 400 acres of alfalfa used for his 400-head dairy operation. When his standard soil test couldn’t explain the yellowing and unevenness in his alfalfa fields he dug deeper including tissue testing for secondary macronutrients and micronutrients. “We discovered sulfur levels were really low,” he says.
He spread one ton of gypsum — a source of sulfate sulfur and calcium — per acre after the first cutting on 150 acres of alfalfa and Ihlenfeld noticed a significant difference.
“There was a 6-inch height difference, the plants were greener and the crop was lush,” he says. “The treated acres yielded 0.6 tons more than the untreated acres on a dry matter basis.”
The success prompted him to apply gypsum on the rest of his alfalfa acres and to some corn and soybean ground.
“Already this spring our hay fields are greener and more even in color than our neighbors that haven’t applied gypsum and the check strips we left are very noticeable,” he says.
After hearing repeated farmer accounts of sulfur improving corn yields, Fabian Fernandez, researcher and assistant professor of soil fertility and plant nutrition at University of Illinois, decided to test response himself. His three years of research farm and on-farm trials seem to confirm the reports.
“We have seen an increase in the frequency and intensity of crop response to sulfur application compared to Illinois trials conducted in the late 1970s which showed little to no response,” he reports. “The responses are very variable, but we are identifying conditions where sulfur applications will be beneficial for farmers.”
Results from a 2006 Iowa State University study on corn yield response to sulfur application showed an average 38-bushel yield response to sulfur application for six sites across northeast Iowa. These sites were specifically chosen for their likelihood of being sulfur deficient.
In small research farm plots not specifically chosen for deficiency, Fernandez found a more moderate average 5-bushel corn yield response to sulfur applications over three years. One of his Illinois on-farm plots, though, yielded surprising results.
“It produced a one-year, 51-bushel corn increase over the check with an application of sulfur,” Fernandez says. “That’s not a normal response by a long shot, but it goes to show that if sulfur is truly deficient it can severely limit yields.”
Less sulfur in rain
Sulfur deposits on farm fields have decreased over the years, in part as a result of emission-reducing technologies used at coal-fired power plants. There is less sulfur in the atmosphere and in rain that hits farm fields.
There is no simple test for determining sulfur deficiency on individual farms, says Warren Dick, a researcher and former professor in Environmental and Natural Resources at The Ohio State University. Researchers have found, however, that certain factors can increase the likelihood of seeing a response to sulfur.
Soil type, cropping history and the crop planted can help determine on which acres farmers should try using sulfur. Soils with low organic matter are a good place to start as mineralization from organic materials is one of the leading sources of soil sulfur.
“Soils with low organic matter, such as coarse texture (sandy) soils or eroded soils likely found on sloping hills, are more likely to be low in sulfur and respond to sulfur applications,” Fernandez says.
Sulfur is an essential ingredient for creating proteins, so high-protein crops (alfalfa, canola, soybean, corn silage) require more sulfur than low-protein producing crops. A lack of sulfur can impact nitrogen utilization and yield.
There are several sulfur sources producers can use to meet crop demand including elemental sulfur one primary source is anhydrite and dihydrate gypsum.
Estimates vary, but roughly one pound of sulfur is needed to be applied to balance up to 16 pounds of applied nitrogen for a corn plant to produce proteins and grow. If there’s adequate nitrogen but deficient sulfur the plant won’t grow to its potential until it has the sulfur to balance that nitrogen. Deficiencies are particularly critical in early growth corn because that’s when yield potential is set. If the upper soil profile, where seedlings are growing, is deficient of sulfur there will be less yield potential.
Sulfur can be recycled back into the soil system through crop residue, Dick says, but in crops such as corn and alfalfa much of the protein — and sulfur — is removed with harvest.
“A 250-bushel corn crop removes quite a bit of sulfur every year without replacing it,” Dick says. “The same is true of hay fields. A lot of nutrients are removed when hay is cut and taken from the field, making alfalfa fields and mixed hay pastures good places to try sulfur applications.”
There are several sulfur sources producers can use to meet crop demand including elemental sulfur one primary source is gypsum.
“Elemental sulfur is used, but it is very acid forming so it isn’t ideal for every situation,” Dick says.
At 16 percent sulfur by volume, gypsum is a budget-friendly option. The cost of a pound of sulfur in gypsum is significantly lower than sulfur in other forms. It also provides sulfur in a plant-available form and moves sulfur through the soil profile so it’s where it needs to be in the form it needs to be in for plants to use it. Gypsum provides the added benefit of 17-20 percent calcium and is often used in potato production and other calcium-loving specialty crops.
Extensive studies have shown all of the various gypsum sources are safe for land application, says Dick.
For Center Point, IN, producer Brad Brown, gypsum provides the double benefit of building soil structure and replenishing sulfur.
“We didn’t know about sulfur when we first started using gypsum in 1986 to loosen our soil for better drainage and rooting,” Brown says. “Getting sulfur with our gypsum was a win-win, it really helps our corn and it’s in the cheapest form we can get. Our yields are more even from acre to acre and year to year. The sulfur seems to excite the corn for good early season growth.”
Brown applies gypsum every other year. Initially he applied one ton per acre but has dropped to 1,400 pounds every other year applied in the fall ahead of corn.
“As the soil structure builds we’re able to cut back on the rate but we will keep applying it to maintain the sulfur supply for our corn. We shoot for 200-plus bushels per acre,” specifies Brown.
Wisconsin producer Ihlenfeld agrees gypsum is becoming a valued tool in his cropping operation. “We were attributing sulfur deficiency symptoms to disease, but now that we know what it is we’re able to correct the situation and our yields improved after only one application,” Ihlenfeld says. “Gypsum is a win-win for us because it boost yields by correcting the sulfur deficiency and the calcium helps loosen up our compacted soils.
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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.
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
Thanks to the generosity of the Arcosa Specialty Materials employees in the Norman, OK office, a local charity was the beneficiary of some well-timed assistance.
Norman employees decided to support The Women’s Resource Center. Since 1975, they been helping women live better lives with a primary focus on people victimized by domestic and sexual violence. The Shelter, the Rape Crisis Center, and the Satellite Office fill an urgent need in the area and . The Women’s Resource Center is the only organization providing these services in Cleveland County.
Between November 4th and December 14th, Arcosa Specialty Materials coordinated a donation drive in the Norman office. Items collected by the employees included clothing, food, and children’s items like toys and diapers.
A big congratulations for the warm hearts of the Norman area employees to help make life a little better for those in need.
Construction Starts Post Solid Gain in August
Total construction starts rose 19% in August to a seasonally adjusted annual rate of $793.3 billion. Gains were seen in all three major building sectors: nonresidential building starts rose 16% and residential building climbed 12%, while nonbuilding construction jumped 40% over the month. While large projects certainly influenced the August gains, removing those projects would still have resulted in a gain for the month.
Year-to-date through the first eight months of the year, starts were 14% lower than in the same period in 2019. Nonresidential starts were 24% lower and nonbuilding starts were down 20%, but residential starts were down less than one percent. For the 12 months ending August 2020, total construction starts declined 6% from the 12 months ending August 2019. Nonresidential building starts fell 13% and nonbuilding starts were 9% lower in the 12 months ending August 2020, while residential building starts rose 3%. In August, the Dodge Index rose 19% to 168 (2000=100) from the 141 reading in June. The Dodge Index was down 8% compared to a year earlier and 6% lower than its pre-pandemic level in February.
“Construction starts continue to make up ground following the nadir in activity in April,” stated Richard Branch, Chief Economist for Dodge Data & Analytics. “Residential and commercial construction are driving the gains, while the public side of building construction is proving to be a drag on growth. The regional pattern has also evened out with gains in starts seen in every region but the Midwest in August — somewhat muting the concern over the potential impact of rising COVID cases in the South and West. The nascent recovery in starts, however, will face challenges as summer turns to fall. The expiration of enhanced unemployment insurance benefits and small business loans that were provided in the CARES Act, the budget crises facing state and local governments, and the impending expiration of the FAST Act on September 30 will all have a dampening effect on starts.”
Nonbuilding construction posted a 40% gain in August to a seasonally adjusted annual rate of $184.4 billion nearly reversing the sizable decline in the previous month as two large projects pushed activity higher. Starts in the utility/gas plant more than doubled, while environmental public works posted an 89% gain and highway and bridge starts moved up 13%. Miscellaneous nonbuilding starts lost 5%.
The largest nonbuilding project to break ground in August was the $1.3 billion Wastewater Control Plant in San Francisco CA. Also starting during the month were the $888 million Dania Beach Clean Energy Center in Dania Beach FL and the $310 million new Aztec Stadium at San Diego State University in San Diego CA.
Through the first eight months of the year, total nonbuilding starts were down 20% compared to the same period in 2019. Starts in the highway and bridge category were up 1%, while the environmental public works category dropped 15%, the miscellaneous nonbuilding sector fell 34%, and the electric power/gas plant category plunged 45%. On a 12-month rolling basis, total nonbuilding starts were down 9% in the most recent year compared to the 12 months ending August 2019. Starts in the street and bridge category dipped 2%, while starts in the electric power/gas plant category were down 12%. Environmental public works starts pulled back 8% and miscellaneous public works starts dropped 21%.
Nonresidential building starts in August were also aided by large projects in the office and manufacturing sectors leading to an increase of 16% to $236.7 million. Removing these projects, however, would not have prevented an increase in nonresidential building starts. Commercial starts rose 36% and manufacturing starts soared 201%. Institutional starts, however, fell 7% despite small gains in education and healthcare.
The largest nonresidential building project started in August was the $1.0 billion Facebook Data Center (Project Woolhawk) in Gallatin TN. Also starting during the month was the $740 million Texas Instruments Fabrication Plant in Richardson TX and a $700 million mixed-use office and hotel project in Boston MA.
On a year-to-date basis, total nonresidential building starts were 24% lower than in the first eight months of 2019. Institutional building starts dropped 16%, while commercial starts slid 27% and manufacturing starts were 47% lower than a year earlier. Over the 12 months ending August 2020, total nonresidential building starts were down 13% from the 12 months ending in August 2019. Commercial starts were 16% lower, institutional starts were down 13%, and manufacturing starts slipped 1%.
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6 Issues Impacting the Commercial Construction Industry
The construction industry has always been important because of its fundamental role in building society as we know it. However, the industry is facing some critical issues that will be crucial for its future development. Here are some of the most essential issues impacting the commercial construction industry.
First and foremost, there’s the issue of safety. The construction industry has been struggling with worker safety for years. The commercial construction industry is one of the leaders in the total number of worker deaths. Keeping workers safe has been a major source of concern among employers within the industry.
There are several ways to protect workers from accidents and injuries while they do their job. The most obvious is training. Training employees to become better at protecting themselves in critical situations can prevent them from getting injured and prevent accidents from happening. Training employees to be better specialists, on the other hand, will help them perform their tasks more accurately, precisely, and safely.
Another way to reduce the number of accidents and injuries in the workplace is by getting rid of hazards. All the safety measures for storage, transportation, and use of potentially dangerous objects should be strictly followed to ensure that the risk of disaster is reduced. Continuously training your workers can also help employees better understand what should be done in different situations and what objects should be stored in what conditions.
Another issue that will ultimately impact the commercial construction industry is the adoption of technology. The construction industry is notorious for adopting new technologies very slowly. Many construction business owners tend to underinvest in new technologies despite knowing that these technologies can significantly improve the results and performance of any project.
Emerging technology like virtual and augmented reality, robots, drones, and 3D printing are all examples of such new underused technologies that are being adopted by the construction industry day by day. Hopefully, more projects will be completed with the help of new technologies.
Many issues and problems listed in this article can easily be solved by using a certain technology. For example, drones can be used to improve security and keep employees safe by monitoring everything from above and ensuring that every process is performed correctly. Project management software can help with scheduling and planning while VR and AR can help with visualizing the final product.
One thing that not everyone anticipates in the construction industry is the labor shortage. Ever since the Great Recession, the employment numbers in the construction industry have been struggling to get back to their prerecession statistics. Over 2 million jobs were shed by the industry during the economic downturn of the late 2000s with workers either leaving voluntarily or being fired.
These workers mostly found jobs in other industries that sustained them for a while. But what happened next is that many of them realized they were better off in those jobs. Many of these specialists didn’t come back to the construction industry creating this labor shortage. Moreover, the construction industry is not attracting enough talent to meet the growing demand for qualified professionals and specialists.
Employers should be more mindful of the experts they already have employed in their firms. More and more companies are realizing how important it is to create the right offer to “sell” their unoccupied positions to potential candidates. If employers have opportunities to offer that others don’t, they are more likely to get to hire the specialist they are looking for, i.e., skilled, experienced, educated, and motivated.
Decreased productivity seems to be a pain point for many spheres, so it’s obvious that the commercial construction industry suffers from it as well. The problem is that construction projects are becoming more and more complex every year which is why the decreased productivity is way more damaging than it seems. Multiple factors lead to decreased productivity which is why it is so hard to prevent it completely.
For example, improper scheduling and planning are some of the primary causes of decreased productivity. When employers and employees have no idea what they are supposed to do and what aims they should be pursuing, they become increasingly demotivated. That’s where the decreased productivity starts setting in. It’s crucial that the proper amount of time is dedicated to planning and preparation.
The lack of collaboration and communication can lead to a lot of time wasted on insignificant matters which also results in less work completed and, consequently, decreased productivity. In addition to all of that, the shortage of labor can contribute to this issue as fewer specialists can be working on one project at the same time. In other words, there are multiple things you should keep in mind to truly start increasing productivity on a construction project.
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The Energy Efficiency of Buildings
How a decades-old design concept is transforming the energy efficiency of buildings
The buildings we live and work in have to meet a wide range of needs, whether it’s an office block in the middle of the city or a small house in the suburbs.
Think of a building’s temperature: It can be regulated by radiators, fans and air conditioning systems, while basic actions such as opening and closing a window or door can also be effective. Today, smart technology allows many of these appliances to be controlled remotely using smartphones.
You only need to look at your monthly utility bill to know that living in a building — be it large or small — costs money.
The impact of buildings on the environment is also a concern. According to the IEA, final energy use in buildings hit approximately 3,060 million tons of oil equivalent (Mtoe) in 2018, up from 2,820 Mtoe in 2010.
Fossil fuels’ share in buildings’ energy use was at 36% in 2018, the IEA says, a small drop compared to 38% in 2010.
The ‘Passivhaus’ concept
It’s not surprising then, that as people around the world become increasingly conscious about sustainability and the impact human actions have on the environment, one idea that is becoming influential is the Passive House – or Passivhaus – concept.
The world’s first Passive House was built in the city of Darmstadt, Germany in the early 1990s. According to the Passive House Institute, which was established in 1996 and is also based in Darmstadt, the concept is grounded in five principles: superior windows; airtight construction; ventilation with heat recovery; quality insulation; and thermal bridge free design. In order to be certified as a Passive House, a building has to meet a range of detailed, strict, criteria.
Today, the concept continues to influence architects and designers around the world. The 2019 winner of the prestigious Royal Institute of British Architects (RIBA) Stirling Prize — which is awarded to the best new building in the U.K. — was Goldsmith Street, a development of around 100 low-rise homes in the English city of Norwich. According to RIBA, the development “meets rigorous ‘Passivhaus’ environmental standards.”
All of the homes, RIBA says, are south facing in order to “maximise solar gain” while each wall is more than 600 millimeters thick. In addition, subtle efforts have been made to boost insulation: these include mailboxes being installed in external porches rather than doors to tackle draughts.
Other examples of Passive House buildings include schools, office buildings and factories, the Passive House Institute says.
Just how important will passive design be in the years ahead, then?
“It is the future of construction – building better,” Giorgia Tzar, associational manager at the International Passive House Association, told CNBC via email.
“Passive House buildings are sustainable not only because they are built to last, but they reduce operational energy — and thus operational emissions — enormously,” Tzar added.
Tzar went on to explain that Passive House buildings offered “soft” or indirect benefits such as lowering the running costs of a building due to low heating and cooling demand.
Indeed, the architecture firm involved in the Goldsmith Street project, Mikhail Riches, says its design was intended to provide residents with fuel bills of around £150 ($191.18) a year.
Karl Desai, from the U.K. Green Building Council (UKGBC), explained to CNBC that another key benefit was the “interaction with the natural environment and ensuring that the building is responsive to what’s happening externally.”
“That … creates a nicer space internally as well,” Desai, who is projects manager for Advancing Net Zero at the UKGBC, added.
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Cave of Crystals “Giant Crystal Cave” at Naica, Mexico is all a form of Gypsum
Discovered by chance, the secret Mexican crystal caves big enough to drive a car through.
The Naica Mine of the Mexican state of Chihuahua, is a working mine that is best known for its extraordinary selenite crystals. Located in Naica in the municipality of Saucillo, the Naica Mine is a lead, zinc and silver mine operated by Industrias Peñoles, Mexico’s largest lead producer. Caverns discovered during mining operations contain crystals of selenite (gypsum) as large as 4 feet (1.2 m) in diameter and 50 feet (15 m) long.
Formation of the gypsum crystals
Naica lies on an ancient fault and there is an underground magma chamber below the cave. The magma heated the ground water and it became saturated with minerals, including large quantities of gypsum. The hollow space of the cave was filled with this mineral-rich hot water and remained filled for about 500,000 years. During this time, the temperature of the water remained very stable at over 50 °C (122 °F). This allowed crystals to form and grow to immense sizes.
How did the gypsum crystals reach such superheroic proportions?
In the new issue of the journal Geology, García-Ruiz reports that for millennia the crystals thrived in the cave’s extremely rare and stable natural environment. Temperatures hovered consistently around a steamy 136 degrees Fahrenheit (58 degrees Celsius), and the cave was filled with mineral-rich water that drove the crystals’ growth.
Modern-day mining operations exposed the natural wonder by pumping water out of the 30-by-90-foot (10-by-30-meter) cave, which was found in 2000 near the town of Delicias. Now García-Ruiz is advising the mining company to preserve the caves.
Exploration and scientific studies
A scientific team coordinated by Paolo Forti, specialist of cave minerals and crystallographer at the University of Bologna (Italy) explored the cave in detail in 2006. To survive and to be able to work in the extreme temperature and humid conditions which prevent prolonged incursion in the crystal chamber, they developed their own refrigerated suits and cold breathing systems (respectively dubbed Tolomea suit and Sinusit respirator).
Special caving overalls were fitted with a mattress of refrigerating tubes placed all over the body and connected to a backpack weighing about 20 kg (44 lbs) containing a reservoir filled with cold water and ice. The cooling provided by melting ice was sufficient to provide about half an hour of autonomy.
Beside mineralogical and crystallographic studies, biogeochemical and microbial characterization of the gypsum giant crystals were also performed. Stein-Erik Lauritzen (University of Bergen, Norway) performed uranium-thorium dating to determine the maximum age of the giant crystals, about 500,000 years.
Penelope Boston (New Mexico Institute of Mining and Technology), speleologist and geomicrobiologist specialist of extremophile organisms realized sterile sampling of gypsum drillcores by making small boreholes inside large crystals under aseptic conditions. The aim was to detect the possible presence of ancient bacteria encapsulated inside fluid and solid inclusions present the calcium sulfate matrix from its formation.
Solid inclusions mainly consist of magnesium and iron oxy-hydroxide but no organic matter could be found associated with the solid hydroxides. No DNA from ancient bacteria could be extracted from the solid inclusions and amplified by PCR.
Microbial studies on fluid inclusions are foreseen to attempt to evidence the presence of ancient micro-organisms in the original fluid solution in which the crystals developed.
Other researches also cover the fields of palynology (pollen study), geochemistry, hydrogeology and the physical conditions prevailing in the Cave of Crystals.
To read the original online article – CLICK HERE
A more sustainable material to reinforce concrete structures
A more sustainable material to reinforce concrete structures of all types from building foundations to high rise towers.
The next generation of ultra high-performance fiber-reinforced concrete (UHPFRC) has just been created at EPFL. The new material will be used to strengthen and to extend the life span of bridges and other structures—both new and old. What’s more, the process of manufacturing this material releases 60–70 percent less CO2 than the previous generation of fiber-reinforced concrete.
The construction industry accounts for around 40 percent of global CO2 emissions, much of which can be attributed to the manufacture of concrete. And countries like Switzerland, where concrete structures have flourished since the 1960s, now face the task of maintaining these structures to ensure they remain safe far into the future. This is a daunting challenge with both environmental and technical considerations.
EPFL’s Structural Maintenance and Safety Laboratory (MCS), headed by Eugen Brühwiler, has built up cutting-edge expertise in this field over the past 25 years. The MCS specializes in two areas: developing more ecofriendly concrete, and carrying out increasingly sophisticated, largely monitoring-based, assessments of existing structures, such as road and rail bridges in Switzerland and around the world.
For his Ph.D. thesis, MCS researcher Amir Hajiesmaeili sought to develop the next generation of ultra high-performance fiber-reinforced concrete (UHPFRC). His aim was to develop a material that retains the mechanical properties found in today’s concrete, but without the steel fibers. The UHPFRC that Hajiesmaeili came up with is 10 percent lighter than other fiber-reinforced concrete, and its environmental impact is 60–70 percent lower. This new material is so effective that the first tech transfer will take place in 2020, when it will be used to reinforce a bridge.
Hajiesmaeili likes food and knows his way around a kitchen. After completing a Master’s degree in civil engineering at the University of Tehran, he came to EPFL to do his Ph.D. as part of the Swiss National Science Foundation’s NRP “Energy Turnaround” (NRP 70) project. He spent nearly four years “cooking” at EPFL. Each week he would prepare various combinations of powders in a scientific way, according to a novel comprehensive packing model that they developed in MCS and stir them up in a mixer. He would then run his samples through various strength and tensile tests and refine his calculations. His aim was to produce a new UHPFRC that is just as strong as the one currently used in the construction industry but that produces less CO2.
“After three years of this trial-and-error, we finally found the right recipe—one that also meets stringent building standards,” says Hajiesmaeili. How did he do it? Instead of steel fiber, he used a very stiff synthetic polyethylene fiber that adheres well to the cement matrix. He also replaced half of the cement, a commonly used binder in concrete, with limestone, a material that is widely available around the world. “The trick was to find a material that’s very strong and produces the right consistency.”
For the past 15 years, first-generation UHPFRC has been used to reinforce bridges to make them more sustainable, thanks to a technology developed in Switzerland and exported abroad. Its carbon footprint is already lower than that of conventional reinforced concrete. “With this material, we can add value to age-old structures by ensuring they will last for a long, long time,” says Brühwiler, whose lab has already overseen the structural reinforcement of more than 100 bridges and buildings in Switzerland. “This solution is also much more financially and environmentally sound than razing and rebuilding existing structures like bridges and historical monuments.”
In Brühwiler’s experience, technology transfer in the construction industry is only effective when three criteria are met: people at every step of the construction chain—from construction managers to workers—are well-trained (as is the case in Switzerland); there is a building code; and there are both financial and individual incentives for stakeholders to change their habits.
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Women in Construction
Women construction leaders discuss building their careers, demolishing glass ceilings.
At the beginning of her career, civil engineer Rebecca Clark tried to stay under the radar and assimilate with her peers — almost all of them men. For many years she thought it was important to not stand out in the workplace.
As she rose in her career and saw more women entering the construction field, she began to embrace her unique skill set.
Clark, now an operations executive at Skanska, was part of a panel at the sold-out Women in Construction Leadership and Networking Conference here on Oct. 19. She and three other women panelists told the audience of 450 that in a male-dominated field like construction, female employees’ skills and talents are invaluable.
These strengths include perceptiveness, organizational and listening skills, empathy and a willingness to collaborate, speakers said.
“Maybe it means you can read somebody’s body language in a meeting or the scowl on their face to know how to pivot the conversation and redirect the discussion to your advantage,” said moderator Clare Archer, vice president at Gilbane Building Co.
Females’ unique set of traits dovetail with those of men in the office and on the jobsite, panelists said. “What I’ve learned over the years from working in this field is that men and women are different and that’s OK,” Archer said.
Brailsford & Dunlavey Senior Project Manager Sarah Pearlstein agreed, telling attendees that when it comes to construction projects, “there’s more than one way to skin a cat. Some people go from A to B to C and some go from A to Z back to B and C,” she said. “Both of those types of people get to C in their own way.”
Panelists provided an array of advice to women in the industry, including:
- Women should not be afraid to stand out at work, Pearlstein said. “Build your personal brand, get involved and make sure you find things that you care about, whether it’s your local Women in Construction chapter or whatever that passion looks like for you,” she said. “Get involved so that it’s not just people in your company but people in the industry recognize you.”
- Clark echoed that sentiment, saying female workers should champion things they are passionate about such as community involvement, mentoring younger workers, or driving change in the workplace. “Even if it’s for something that’s going against the tide, you will stand out if you’re passionate about whatever initiatives you’re behind.”
- Archer recommended the book “How Women Rise: Break the 12 Habits Holding You Back from Your Next Raise, Promotion, or Job” by Sally Helgesen as a resource to help identify and overcome issues that slow women’s career success.
- Women in construction have to be thick-skinned and willing to claim their achievements, Archer said, urging audience members not to diminish their worth. “Sometimes we minimize with our words, such as “this will just take a minute’ or ‘I just need you for this one quick thing,’” she said. “This gives the impression that your opinion isn’t valuable enough for anyone to spend time listening to.”
- Female managers should try not to take it personally if coworkers disagree with a decision. “It’s just not possible to always make everybody happy,” Pearlstein said. “Don’t feel like if people aren’t pleased with the way you’re moving forward that you made the wrong decision.”
- Additionally, if a woman makes a mistake, she should avoid dwelling on it, said panelist Amy Mercurio, senior director of design and construction for Johns Hopkins Facilities & Real Estate. “I’m constantly Monday morning quarterbacking,” she said. “It’s better to accept what you did and know you’ll do better next time.”
- A common habit of female employees, sharing personal information, sometimes puts women in a negative light, Archer said. “Women share their faults and problems as a way to bond with one another,” she said. “Men don’t do that, and for the most part they set workplace cultural standards around the world so routine personal disclosures about your doubts and weaknesses are more likely to diminish your credibility than to help it.”
- All panelists mentioned the importance of developing mentors, both men and women and both in and out of the construction industry. “Find a safe space of coworkers that you can trust,” Clark said. “There’s a lot of power in that.”
- Pearlstein noted that making time for working with a mentor is important but sometimes difficult. “Those types of relationships require some work, because the person might not be three doors down the hallway from you,” she said. “Go to lunch, grab coffee, make those long-lasting relationships. They’ll really go a long way.”
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