Modern Materials Technology
Materials technology is of endless fascination to architectural designers and planners, and the designers/planners of healthcare projects are no exception. Recent years have seen innovative developments not only in patient- and staff-friendly layouts and amenities, but in construction of the basic structures themselves. As examples, HEALTHCARE DESIGN Managing Editor Todd Hutlock explored some recent applications of structural glass and precast concrete in healthcare projects, including the potential alternatives, advantages, and precautions involved in their use in building modern healthcare facilities
Interview with Michael McGeady, Jonathan Bailey Associates, London
Do you see trends toward increased use of structural glass in the healthcare design market?
Yes. I think what you would see in the past was healthcare design that was more utilitarian. The service that was delivered was more important than the look of the building, and I think that still holds true in that the services delivered inside the building is more important than the image. What we see happening now is that brand awareness and other aesthetic issues have led to discussions during planning that the hospital structure itself needs to convey the imbedded philosophies of the institution itself. They want to attract the best quality clinicians, as well as attract patients.
The more our hospitals become highly thought of public institutions, so to speak, the more importance will be placed on the aesthetics of the building itself. As that awareness grows, people will be looking for a higher level of design aesthetics, and because of that, we're looking toward an overall trend in the use of structural glass, from its use with some of the high-tech architects and permeating through the profession. We're seeing an increase in the use of structural glass for main public spaces, atria, and view corridors because of this.
Are there any recent technological developments that are driving an increased use of structural glass?
Low-E coatings have produced higher levels of light transmission and greater environmental efficiency. Glass production as a whole has improved and made structural glass a more cost-effective solution than it has been in the past. It used to be very expensive and therefore prohibitive to use. It's now being manufactured in larger pane sizes, which is also useful. It tends to be the case that the main expense of the system itself is the support mechanisms used to support the glass, and with larger pane sizes, that isn't as much of an issue.
What are some advantages of structural glass versus other building materials?
If you look at structural glazing for public areas I mentioned compared to traditional curtain wall solutions, you'll find that you were losing as much as 30% of your actual glass area when you use a curtain wall support system. With the structural glazing systems, especially those that use glass as the supporting system as opposed to metal support pieces, you'll see a substantial reduction in obscured area.
The larger pane sizes are an advantage, as well, and speaking as an architect, that is something that we've always wanted—a larger, clearer area with less obstruction of views. Manufacturers have now responded to the design professionals by producing these larger pane sizes, but the only problem the manufacturers are finding now is in transportation to the site. Their ability to manufacture the material is superb, but getting it there is still a challenge at times.
Are there precautions that need to be in place to ensure the best results when using structural glass?
There are very specific concerns that need to be considered in terms of transportation and placement. Health and safety issues involved in the installation, maintenance, and replacement of the glass should be a major consideration of the designer and all construction partners. There needs to be some sort of practical restriction on manual handling of the glass by the workers on site who must physically move these units into place. I'm a firm believer in incident- and accident-free construction sites, and I don't think that enough designers think about that. Those health and safety issues have to be paramount in everyone's mind when making design decisions.
Questions need to be asked, such as: where is this piece of glass to be used? If it is an atrium, is it in the center of the building? What are the handling issues around that piece of glass—for example, how is it going to be craned into place? If it is an atrium or a facade, how many pieces of glass are there? What's the construction sequencing? I think these questions need to be more in the forefront of people's minds when undertaking a construction project of this type. Bovis Lend Lease is one contractor that is fostering an understanding of these issues through its incident- and injury-free policy worldwide.
Can you cite some examples of structural glass being put to particularly creative use?
The Winnie Palmer Hospital for Women & Babies (see this month's Showcase on page 44) in Orlando, Florida, features structural glass used as a portal for the main entry into the building. There is a water fountain that flows over the top of this goalpost-type portal, so as you enter the hospital, it's as if you are walking through a waterfall. The Evelina Children's Hospital in London also features some fun and interesting uses of structural glass essentially in the creation of main public spaces, but also in internal use for partition separation between circulation areas and clinical spaces.
Interview with Dean Gwin, Gate Precast Company, Jacksonville, Florida
Do you see trends toward increased use of precast concrete in the healthcare design market?
We have seen an increase, mainly because of the sustainability, durability, and permeability of precast concrete, as well as the LEED points that can be achieved with precast (see sidebar). Many of our plants are in Florida, and precast has become very popular there because of its ability to withstand the heavy winds that come during hurricane season. I would say that the majority of hospitals in Florida are using precast now.
Precast also makes designers comfortable because of permeability factors; the lack of joints helps keep out moisture and therefore mold and mildew, and you aren't going to get moisture through a six- or eight-inch panel. This increase has been steady and strong over the last six or seven years during this latest hospital construction boom.
Many hospitals being built today are being constructed to last for 100 years rather than just 20 or 30 years, and from a durability standpoint, precast makes sense.
Are there any recent technological developments that are driving an increased use of precast concrete?
Thinbrick has become more popular. Thinbrick is cast in panels, and we can use it to replace block, brick, vapor barrier, and even insulation with just one panel. It's much faster and more durable. In what would have been a traditional brick hospital building, you can now use precast concrete with thinbrick on the face and still have all of the benefits without having to use masons. Thinbrick has been around for a while, but there is a lot more you can do with it now. There's nothing that a mason can do that we can't do with thinbrick now.
Different colors and finishes on the face of the precast have made it more popular, as well. A pitted, coral stone-look finish is very popular here in Florida. It looks like a porous piece of coral stone, but its really six inches thick of solid concrete that you can depend on, and designers seem to like that. Many hospitals being built today are going for more of a “resort” or hospitality look, and this flexibility has really played a role in precast's increased popularity.
What are some advantages of precast concrete versus other building materials?
Speed of construction is the biggest advantage. Using precast as opposed to hand-set stone, brick, or block is probably in the neighborhood of 75% faster.
We also have been using carbon fiber for both reinforcing and as a composite connector in panels that have insulation in the center. This will also work as a vapor barrier, so again, with one panel, you are replacing many layers of other materials that would have to be used to achieve the same results
Are there precautions that need to be in place to ensure the best results when using precast concrete?
The most crucial thing is that the planners seek consultation from us as early in the process as possible. This way, we can maximize efficiency, whether in scoring LEED points or simply from a cost standpoint.
A repetitious piece that can be used throughout the midsection of a building can be poured in one mold, which cuts down on the expense of using multiple molds. The number of pieces used is another important thing to consider from both a financial and a timeliness standpoint. You don't want panels too large for the cranes to pick up at the site, but you also don't want too many small panels that will drive up your cost and take longer to install. Finding that happy medium is important.
Can you cite some examples of precast concrete being put to particularly creative use?
St. Jude Children's Research Hospital in Memphis has an interesting use of color that stands out for me. The University of Florida Genetics and Cancer Research Center in Gainesville, Florida, is next door to the University of Florida campus, which is mainly brick, so they wanted to use a traditional brick look that we were able to achieve by using thinbrick. That project also achieved many LEED points through the use of precast. Aventura Hospital in Aventura, Florida, is an example of a facility that achieved a resort-like feel by using precast. The building is warm and inviting without that institutional look. HD
Michael McGeady is Associate Principal at the London office of Jonathan Bailey Associates. For further information, e-mail firstname.lastname@example.org or visit http://www.gateprecast.com.