Author Archives: CS Editor

Restroom partitions complement school expansion

High-density polyethylene (HDPE) particitions were specified for the new Science Centre restrooms at Lake Forest Academy in Lake Forest, Illinois. In total, seven partitions were furnished and installed—three in the men’s bathroom and four in the women’s bathroom. Photos courtesy Scranton Products

High-density polyethylene (HDPE) partitions were specified for the new Science Centre restrooms at Lake Forest Academy in Lake Forest, Illinois. In total, seven partitions were furnished and installed—three in the men’s bathroom and four in the women’s bathroom. Photos courtesy Scranton Products

by David Casal

Lake Forest Academy (Lake Forest, Illinois) is one of the country’s most renowned boarding schools, and as its population grew so did the need for new dormitories and additional facilities. Established in 1857 as a boys’ preparatory department of the former Lind University, the addition of the girl’s preparatory department came in 1869—currently, there are 425 students in grades nine through 12.

In the 1950s the school expanded its campus by adding more than 10 common areas, dormitories, and sporting facilities. The Science Center, the newest addition to the 40,412-m2 (435,000-sf) campus, was completed in August 2013.

Kelly Mede, director of facilities, and her team had the opportunity to specify the building materials from the ground up.

“Since this was a Science Center, our goal was to create a learning environment that was clean and modern-looking,” said Mede. “The plan was to have natural stone, concrete, and steel/chrome accents throughout the structure, as well as an atrium in the center.”

Selection of the bathroom partitions for the new Science Center was easy—Mede knew exactly what had worked in other buildings.

“We’ve done several renovations here on the campus and for the bathroom partitions, we had started to move away from traditional metal to high-density polyethylene (HDPE), a material that is much more durable and easier to maintain,” said Mede, who oversees the repairs and maintenance of all campus buildings. “The metal partitions had rust problems and required a lot of maintenance. Hinges need to be replaced frequently and the partitions peeled so they often required repainting.”

The solid plastic partitions are non-porous and resistant to bacteria as well as easy to maintain.

The solid plastic partitions are non-porous and resistant to bacteria as well as easy to maintain.

Solid plastic bathroom partitions were specified because they were found to be durable and could alleviate many maintenance and cleanliness issues associated with the metal partitions. Constructed from premium HDPE, the partitions also offer a sustainable solution for restroom stalls.

Mede suggested of the continued use of the partitions with the building committee; it concurred, choosing a stainless steel color. The texture has a pattern of raised dots with a ridged texture and, even though they are manufactured of solid plastic, the partitions feature a bold, metallic look without the high cost of stainless steel. Seven partitions were furnished and installed in the Science Center—three in the men’s bathroom and four in the women’s bathroom.

“The key to this project was finding an alternative to expensive stainless steel restroom partitions. The color and texture look just like stainless steel and is perfect for the contemporary design of the new Science Center,” said Mede. “Their sleek, modern look is exactly what we were going for.”

Cleaning can be a problem with wood or metal partitions, especially with mars in surfaces that can harbor bacteria or are prone to graffiti. That is why HDPE designed to look like metallic or wood finishes are becoming popular, both by aesthetic-minded designers and maintenance managers who oversee cleaning staff. The specified finish offers an additional layer of protection against scratching, markers, and other forms of vandalism.

From a cleanliness point-of-view, the partitions provide the academy with another substantial benefit—the non-porous surface of HDPE is naturally resistant to bacteria, odors, mold, and mildew. From drinking fountains, water faucets, or computer keyboards, schools can be a hotbed for germs; avoiding them is nearly impossible. HDPE does not retain germs and the surface is easy to clean. Graffiti also wipes off easily with most non-abrasive cleaners. The partitions can be power-washed and steam-cleaned without the worry of rust.

According to Mede, the partitions have proven to be low-maintenance.

“We’ve had virtually no maintenance issues in any of the restroom stalls and they look as good today as when we first installed them,” she explained. We simply wash them down from time to time and they look virtually brand new after almost a year of use.”

David CasalDavid Casal is the director of sales and marketing for Scranton Products, a North American manufacturer of HDPE partitions, lockers, vanity tops, and shower stalls. He leads an international team of sales and marketing professionals that work closely with the architectural and end user communities to use and understand the advantages of HDPE materials. Casal can be contacted by e-mail at dcasal@scrantonproducts.com.

Using UHPC to improve box-beam bridge performance

Pouring ultra-high-performance concrete (UHPC) for longitudinal joints—the material could offer new benefits in box-beam bridge design and construction. Images courtesy Ohio University’s Russ College of Engineering and Technology

by Eric Steinberg, PhD, PE

Out of the many types of bridges used across the country, adjacent prestressed, concrete box-beams have become popular for short and medium spans. Since these bridges are cost-effective, fast to construct, and easy to design, they are preferred by many state and local agencies. Currently used in about two-thirds of the country, many of these bridges are now approaching the end of their life span.

Despite the widespread use and preference of these box-beam bridges, there are still some disadvantages associated with durability and effectiveness. As part of a recent project with a team of students and colleagues, this author tested a box-beam bridge to failure in order to gauge behavior and overall capacity.

This project prompted a major understanding in the way box-beam bridges perform. It showed the bridges perform well under stress, but the longitudinal bridge joints are susceptible to cracking and leakage, leading to accelerated corrosion, and reduced load transfer. The research also demonstrated complex behavior in the box-beam bridges due to thermal cycles, craftsmanship, and loading.

While box-beam bridges have clear advantages, it is important to find ways to ensure they have a longer lifespan and handle the issues related to the longitudinal bridge joints. Right now, these bridges last about 30 years (depending on various factors), but if this time frame can be expanded, then owners will save on long-term infrastructure replacement costs. One solution this author is currently examining at Ohio University’s Russ College of Engineering and Technology is a new use of ultra-high-performance concrete (UHPC) in box-beam bridge design and construction.

UHPC is an effective concrete material with superior properties to typical concretes and grouts, because it has a compressive strength greater than 150 kPa (22 psi) and a tensile strength in the range of 7 MPa (1 ksi). Also, the steel fibers allow for ductile behavior. According to the Federal Highway Administration (FHA):

The mechanical and durability properties of UHPC make it an ideal candidate for use in developing new solutions to pressing concerns about highway infrastructure deterioration, repair, and replacement.

This author first became involved with the material in September 2002 during a research trip to Paris, France, where it had been developed and was being used. There are currently 28 UHPC bridges in the United States and 26 in Canada. UHPC is expected to be specified for more projects, and there are numerous signs of the material’s rising importance in civil engineering. In November 2015, for example, the 1st International Interactive Symposium on Ultra-high-performance Concrete will take place at the University of Connecticut. (This author is part of the organizing committee.)

Installation of instrumentation and wiring for the monitoring described in this article.

Installation of instrumentation and wiring for the monitoring described in this article.

Overall, UHPC is an expensive material, and full bridges made out of this type of concrete will significantly increase construction and design costs. The breakdown is as follows:

  • 712 kg/m3 (1200 lb/cy) of portland cement (28.5 percentage by weight);
  • 1020 kg/m3 (1720 lb/cy) of fine sand (40.8 percent);
  • 231 kg/m3 (390 lb/cy) of silica fume (9.3 percent);
  • 211 kg/m3 (355 lb/cy) of ground quartz (8.4 percent);
  • 30.7 kg/m3 (51.8 lb/cy) of high-range water-reducer (HRWR) (1.2 percent);
  • 30 kg/m3 (50.5 lb/cy) of accelerator (1.2 percent);
  • 156 kg/m3 (263 lb/cy) of steel fibers (6.2 percent); and
  • 109 kg/m3 (184 lb/cy) of water (4.4 percent).

There is no large aggregate in the mix.

As UHPC can be costly, there is a search to find methods to supplement cost on concrete box-bridges while finding a way to avoid some of the cracking that leads to corrosion. The solution in which this author has been involved uses UHPC in the longitudinal bridge joints with dowel bars—a relatively new idea. After some analysis using finite element models, a box-beam bridge with UHPC in the longitudinal joints in Fayette County, Ohio, was built near Washington Courthouse.

By July 17, 2014, the beams and joints had been cast and set. The structure was monitored with instrumentation right after the joints were cast for approximately a week. Load testing was carried out on August 8 with a team of graduate students. Several loaded dump trucks were positioned on the bridge, as well as moving at various speeds over the bridge.

We know bridges are affected by the daily thermal cycles from day to night. Additionally, instrumentation was left on the bridge and will be monitored during the cooler season of late fall or early spring. The bridge was opened to traffic on August 13. Diagnostics are currently being run on the data obtained from the bridge—while those results are not yet in, the belief is using UHPC in the longitudinal bridge joint has the potential to save money and time on the long-term costs of infrastructure.

There is also potential in using this type of technology to update older bridges. At a recent conference, a few students from Virginia Tech approached this author, discussing their plans to use ultra-high-performance concrete for bridge repair. It seems the use of UHPC in new and creative ways is not far away.

steinberg-small-2Eric Steinberg, PhD, PE, is a professor in civil engineering at Ohio University. He served as assistant chair from 1997 to 2005 and is a registered engineer in the State of Ohio. A member of the American Concrete Institute (ACI), American Society of Civil Engineers (ASCE), and Precast/Prestressed Concrete Institute (PCI), he is a board member of Ohio’s Research Initiative for Locals, and has served as an expert witness in the field of structural engineering. Steinberg is an active member of PCI’s Student Education and Bridge Committees, and has been faculty advisor for student organizations of ASCE and Structural Engineers Association of Ohio (SEAO). He can be reached via e-mail at steinber@ohio.edu.


Ohio University Online

ASHRAE defining biomass for green standard, consolidating with IAQ group

Changes are occurring on the green building front, with American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) exploring the inclusion of biomass in a high-performance standard and consolidating with the Indoor Air Quality Association (IAQA). Photo © BigStockPhoto

Changes are occurring on the green building front, with American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) exploring the inclusion of biomass in a high-performance standard and consolidating with the Indoor Air Quality Association (IAQA). Photo © BigStockPhoto

Earlier this month, the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) made announcements regarding biomass inclusion and indoor air quality (IAQ) structuring.

Working with the U.S. Green Building Council (USGBC) and the Illuminating Engineering Society (IES), the association is exploring biomass requirements for inclusion in their co-sponsored green building standard.

ASHRAE/IES/USGBC 189.1, Standard for the Design of High-performance Green Buildings, contains minimum requirements for the siting, design, and construction of buildings in support of reducing building energy, resource consumption, and other environmental impacts. To that end, the standard contains requirements for the use of renewable energy systems such as solar, wind, and geothermal. Its committee recently considered a proposal to add biomass to the definition of renewable energy systems, which was submitted by an interested individual from outside the committee. In this context, biomass includes organic material, such as wood and crop waste, that can be burned to generate thermal energy.

At ASHRAE’s 2015 Winter Conference in Chicago, the committee voted not to accept the proposal to simply add “biomass” to this definition. However, in response to the proposal, it stated it intended to work on a definition of biomass, as well as requirements on its use to meet renewable energy requirements.

In other news from that conference, ASHRAE has finalized a consolidation with the Indoor Air Quality Association (IAQA), which will become a part of the larger organization while maintaining its own brand, independence, and board of directors.

“We are excited about the opportunities presented by this,” said Tom Phoenix, ASHRAE president. “It opens the door to alignment of ASHRAE and IAQA programs to create high-impact resources for building professionals around the globe.”

“This is an historic event for both associations and has great promise for growth and development,” agreed Kent Rawhouser, IAQA president. “The consolidation will open new avenues for programs and benefits for our members.”

In July 2014, ASHRAE announced it had agreed in principle to join forces with the IAQA, combining resources to improve indoor air quality in the built environment.

Landscape architectural firms reporting drops in late 2014

Across the board, most landscape architecture firms described business conditions for 2014 as stable to significantly better than the previous year. Photo © BigStockPhoto

Across the board, most landscape architecture firms described business conditions for 2014 as stable to significantly better than the previous year. Photo © BigStockPhoto

Many landscape architectural firms reported quarterly dips in billable hours and inquiries for new work in last year’s fourth quarter, according to the American Society of Landscape Architect’s (ASLA) latest Business Quarterly survey.

The survey found about 75 percent reported stable to significantly higher billable hours—a notable decrease from approximately 84 percent the previous quarter. Some 77 percent said inquiries for new work were stable to significantly higher, which is another decline from 84 percent in the third quarter.

Year to year, more than 80 percent of firms indicated stable to significantly higher fourth-quarter billable hours—a slight dip from the fourth quarter of 2013 (81.5 percent). Additionally, approximately 85 percent said inquiries for new work were stable to significantly higher, which is a jump from the fourth quarter of 2013 (81.5 percent).

Across the board, most firms (87.5 percent) described business conditions for 2014 as stable to significantly better than the previous year. Of all firms with two or more employees, a little over half said they planned to hire in the first quarter of 2015, a slight rise from the third quarter.

Asphalt roofing projects awarded

D&D Roofing’s work on Thomas Jefferson High School earned a Quality Asphalt Roofing Case Study (QARC) Award. Its built-up roof (BUR) system comprises multiple redundant layers to protect the Denver school from Colorado’s weather. Photo © David Pahl, Stack

D&D Roofing’s work on Thomas Jefferson High School earned a Quality Asphalt Roofing Case Study (QARC) Award. Its built-up roof (BUR) system comprises multiple redundant layers to protect the Denver school from Colorado’s weather. Photo © David Pahl, Stack

The Asphalt Roofing Manufacturers Association (ARMA) named its top projects, emphasizing ways in which the material was used to solve challenges or offer protection, rather than solely aesthetics.

Gold went to D&D Roofing for the new assembly installed at the Thomas Jefferson High School in Denver, Colorado. The school selected a redundant built-up roof (BUR) system to protect its staff, students, and equipment from not only heavy snow storms, hail, and high winds, but also the blazing sun.

The Silver award was given to IronClad Exteriors, for its work on the Grand Lodge at Deer Valley in Park City, Utah. This ski resort condo complex needed a new asphalt roof that would prevent heat from escaping through the attic and causing ice damming when snow melts and refreezes at the eaves.

Tom Goldston Roofing took Bronze for the Rosenthal residence in Glennbrook, Nevada. The house required fire-resistant asphalt shingles because of its location in a heavily wooded area of South Lake Tahoe. The homeowners also wanted the shingles to resemble the look of the original wood shake roof.

“These winning projects illustrate when a building requires protection and reliability, asphalt roofing can also provide a solution that incorporates beautiful design,” said Reed Hitchcock, ARMA executive vice president. “Whether through protection from the elements, reliable insulation, or fire-resistance, asphalt roofing solved a problem for each building while meeting the aesthetic requirements of the job.”

The annual Quality Asphalt Roofing Case Study (QARC) Awards program honors North America’s best architects, contractors, and specifiers who use asphaltic roofing materials on low- and steep-slope building projects. The judges represent the trade media (including the editor of The Construction Specifier), the roofing industry, and building and construction. For the low-slope commercial systems, judging focused on the project’s reliability, performance, and affordability, along with overall aesthetics. Steep-slope projects were evaluated based on how asphalt shingles solved the homeowner’s problem and provided the look they desired through different asphalt shingle colors, textures, and the overall curb appeal.

ARMA is now accepting submissions for the 2016 awards campaign. For more information, visit www.asphaltroofing.org.