Hello everyone. Welcome to PCI's webinar on Holocore Floors and Walls. There will be two of us presenting today. My name is Clinton Krell. I am an engineer and business development manager for Spancrete in Waukesha, Wisconsin. I'll be covering the first part, which focuses on what Holocore products are and how they are designed and produced. Then, Paul Corrigan from Aleene Concrete will discuss the features and benefits of Holocore and Precast Concrete. Today's presentation is an AIA CES approved webinar. It is also an NCEES registered program. I know this presentation is starting out with a lot of words on slides, but I assure you it will turn into mostly photos and images soon. We just need to get through the mandatory language first and the course description and learning objectives. Then, we'll be moving on into some photos. This course instructs participants how to design and build using Holocore Floors and Walls. Participants also learn about the inherent fire resistance of Holocore, a major life safety consideration. Participants will be able to identify the different Precast, Pre-Stressed Holocore Concrete systems and explain the benefits of using Precast, Pre-Stressed Holocore Concrete with owners and other designers. Today's learning objectives are to identify the different Precast, Pre-Stressed Holocore Concrete systems, explain the benefits of using Precast, Pre-Stressed Holocore Concrete, discuss the benefits of using Holocore Concrete with owners and other designers, and discuss the basics of Holocore Concrete Floors and Walls. This is an image of Precast Holocore Concrete plank used for floor and roof structures. Plank comes in thicknesses of 6 inch, 8 inch, 10 inch, 12 inch, and 16 inches. Holocore obviously gets its name from the hollow voids that run the length of the plank. The purpose of the cores is to eliminate unnecessary concrete and weight, which allows for a thinner section to span farther and support more superimposed load. These planks have been cut, cast, cut to length, and are awaiting delivery to the job site. You can see that each one of these has a tag on it. Each tag represents what job number it is, its date cast, and also they have a number that indicates where on the structure that specific plank needs to be placed. Every manufacturer of Holocore plank has their own unique cross sections, mostly driven by their production process, as you'll see shortly. Each Holocore plank is custom designed and produced based on the project's specific needs. The shape of the edges of the Holocore plank allow adjacent plank to be grouted after they are erected, which engages multiple planks to work together to distribute concentrated loads. In this image, you can see there is a geometric shape along the sides of each plank, and here you can see that geometric shape runs the entire length of the plank on both sides. Holocore products are made up of two major components, durable high-strength concrete and high tensile strength steel strands. This combination of materials results in a thin, lightweight, long-spanning structural floor or roof system capable of supporting heavy loads. These are spools of high-strength steel seven-wire strand. These strands are composed of six smooth wires wrapped around a larger center wire, which makes the strand flexible so they can be shipped in spools like this. Strands come in different diameters and strengths, which can be chosen based on the structural requirements of the plank. The concrete cover, measured from the bottom of the plank to the bottom of the strand, can be increased to provide fire ratings up to four hours. As you can see in this photo, there is some rust forming on the strand. Typically, it pools in the bottom or the very top. This is okay on the strand as long as there's no...and therefore, reduces the strength of the strand. Rust actually improves the bonding of the concrete to the strand due to the microscopic roughness created on the surface of the strand from the oxidation process. Production begins by pulling multiple strands down long-line pre-stressing beds. The number of strands depends on the structural requirements of the plank. Long-line beds like these increase the cost efficiency of hollow core plank. The big red blocks on the end are called pre-stressing abutments, and they are at the end of each bed. The abutments are made up of heavy steel and are embedded in a giant mass of concrete that is cast underground, which is designed to resist the enormous tension force of the strand. The strands are first pulled tight against the abutment using a hydraulic jack. These are the strands located here, and there are chucks on each one of these, and that's what holds the strand against the abutment. The strands are then stretched until they reach a pre-specified force and elongation. The next step is to cast concrete around the strand. There are different methods used to create hollow voids in hollow core plank, and each manufacturer has their own process. But there are three main types of production process, slip form, extruder, or fixed form. Slip form and extruder type machines tend to use a very dry, low slump concrete with just enough moisture for hydration of the cement. Think of the consistency as of this concrete having the consistency of damp sand used to make sand castles. The stiff concrete maintains its shape after the void is formed. Fixed form machines tend to use a more conventional concrete that is cast around inflated pneumatic tubes to create the continuous voids. This is an image of a slip form machine. It's similar to an extruder in that the machine moves down the long line production bed while leaving behind the hollow core plank. Concrete is being cast directly onto the strand that was previously stretched along the bed. The concrete cast behind the machine has the hollow voids within it and is maintaining its shape due to the dry concrete mix. This is an image of a fixed form steel bed with pneumatic tubes creating the hollow voids. Conventional concrete is poured into the form, and when it cures, the pneumatic tubes are deflated and pulled out of the concrete, leaving the continuous voids. Either method of production can produce insulated wall panels used in vertical applications. These panels typically have insulation across its entire width and along its entire height. Here you can see a worker installing insulation right on top of a precast hollow core section. Insulation type and thickness can be varied based on the project's performance requirements. The face is joined to the structural width of concrete through the insulation by stainless steel C-hooks like in this picture or other methods. Some manufacturers add a layer of pre-stressed strand on top of the insulation to be cast into the face in the next step, and the benefit of pre-stressing the face is that a compressive force is applied to the concrete, reducing the likelihood of cracks forming in the concrete. An architectural face is poured directly onto the insulation and around the strand, creating a sandwich-type concrete wall panel. Colored concrete can be used in the face mix, and additional surface finishes are applied during or after the face concrete has been cast. After the concrete is cast, plastic sheets are pulled over the curing concrete in order to prevent moisture from escaping the concrete, like you see in this upper photo. Insulation may also be placed on top of the plastic to trap heat to promote faster curing. These planks are cut to length the very next day, so high concrete strength is imperative to make sure the strand bonds with the surrounding concrete. The plank are stripped from the bed and stored in the yard to await delivery to the job site. At the site, the plank is immediately lifted off the delivery truck with a crane and placed into its final position. Again, you can see the geometry of the keyway joint that is formed into the side of the plank, and this is a photo of the top of the precast deck after it's erected, and the keyway joints are being grouted with a grout pump. When the grout cures, the planks will lock together and become one monolithic system. Openings can be easily cut or framed into the hollow core plank system. You'll want to make sure, though, that all openings are approved by the precast engineer during the design phase so they can be easily accommodated into the precast design. This image illustrates the interaction of the pre-stressed strand and the concrete after the plank are cut to length. This white line here represents the pre-stressed strand. Remember, the strands were stretched, and they are concentrated near the bottom of the plank. Then the concrete was cast around them. When the planks are cut, the strand wants to return to its original length, so they get shorter. This shortening of strand compresses the concrete around the strand, resulting in an upward bending force that's exaggerated in the image. This upward bending is called camber, and all pre-stressed concrete has some degree of camber. This mechanism that creates the camber is also responsible for the long spans and heavy load-carrying capacity of hollow core plank. An additional site-cast concrete topping is recommended to provide a flat floor surface if that is required. If additional strength or stiffness is required of the precast system, a bonded concrete topping can be placed on top of the plank. All that is needed to bond a concrete topping is to properly prepare the surface by blowing off the surface dust and debris, thoroughly wetting the precast surface, and removing the ponded water immediately prior to pouring the topping. That is called having the surface saturated surface dry. To ensure proper manufacture and a quality finished product, specifications should insist that precast components be produced in a PCI certified plant. Every PCI certified plant is subjected to two random two-day inspections per year, and each type of precast product produced by the plant must undergo its own inspection due to the various casting methods of each product. The inspection auditors assure those who specify precast that the precast will be uniform in quality and meet specifications. PCI certification guarantees reliability, durability, uniformity, and precision in the precast products manufactured in that plant. A great resource for hollow core precast design is what's referred to as a hollow core manual, or more specifically, the PCI manual for the design of hollow core slabs and walls, MNL126. PCI's website has this manual available for download or purchase. Hollow core plank are designed to be used as a system to work together and share loading, and in this manual, the methodology for designing plank for concentrated loads is described. Also outlined in MNL126 is the procedure for designing the plank system as a diaphragm for distributing lateral loads. This is a diagram of how concentrated loads are distributed in a hollow core plank system for both interior conditions, like this, or edge conditions, like this. L is the length of the span of the precast plank, and all the individual vertical lines represent the keyway joints of adjacent plank. Concentrated loads, such as line loads or point loads, are resisted by more than one slab, and it's the grouted keyway joints that allow the loads to be shared between the precast plank. The diagram illustrates that concentrated loads applied near the center of the span, or the middle half of the span, will distribute further and across more plank than those applied near the end or the bearing end of the precast. This distribution is the result of the deflection of the plank. The more a plank deflects, the more it engages the adjacent plank. So, any loads applied near the mid-span, the plank is going to deflect more, so therefore it distributes across more plank. If you have heavy concentrated loads on a project, I recommend consulting a local precaster to confirm that the plank you choose has adequate strength. Generic load tables can also be found in this manual. They help designers choose the right thickness of plank based on span and loading criteria. However, load tables specify allowable uniform load only and don't consider the effects of concentrated loads. Concentrated loads increase local stresses and may require modification of the plank, such as custom cross-sections or grouting core solid, to increase the shear strength of the plank. Keep in mind that all precast manufacturers' hollow core plank is unique, and so are their load tables. There are some specific manufacturers' plank design information in this manual. However, I would recommend that you download their up-to-date information available on their websites because precasters often make changes to improve their products. Another good resource available from PCI worth mentioning is the PCI Design Handbook, now in its 7th edition. It contains an immense amount of information and data on precast systems, details, and example problems. Now that you have some background in the design and production of hollow core precast, Paul will explain its features and benefits. Hello, everybody. My name is Paul Correggion, and I work for Moline Concrete in Minneapolis. I'm going to talk about some of the features and benefits of hollow core, as you've heard. So, we'll proceed with that. The finished hollow core products offer a variety of key features. These include the shallow depth of the section, reduced weight and long economical spans, control of deflection and flexural cracking, and better acoustical control and fire resistance. These features, in turn, translate into direct benefits that aid everyone in the construction cycle. Benefits derived from these hollow core features include such key elements as faster erection times, lower long-term maintenance needs, less noise between rooms and floors, better fire resistance, lower insurance rates, better aesthetic appeal, and lower total costs. Maintenance over the life of a building is a key factor that all owners and designers must consider when planning their projects. The low cost of maintaining hollow core concrete projects in the as-constructed mode makes a compelling argument for specifying the material. Not only does it require less money overall to repair balconies, porches, exterior walls, and other components, but it ensures the lender that the building will outlast the mortgage, making it easier to acquire funding. In addition, hollow core's durability ensures that the building retains its aesthetic appeal to attract tenants many years hence. The building you see here is the WSAAF Barracks Expansion in Watertown, New York. Hollow core planks provide a long, durable span that offer low maintenance. In this design, the planks used a cantilever design that does not rely on the exterior end wall for support. So, in the event of a blast in which the end wall, which would normally support the slabs, is destroyed, the precast slabs can cantilever that 10 feet from the interior bearing wall and remain supported. While any type of precast concrete exterior offers a wide variety of distinctive looks that can mimic many more costly materials, hollow core offers benefits that go beneath the skin. These include one of the most critical to building occupants today, privacy. This is because the cavities within the hollow core walls and floors act to dampen sound vibrations. This results in them transmitting less noise between spaces than other types of construction, including conventional wood framing. That, in turn, means less intrusive sound from overhead or next door in either apartments or offices. In essence, hollow core products make for good neighbors. This project is the Hampton Inn in Bloomington, Minnesota. This building was located adjacent or is located adjacent to the final approach of the Minneapolis Airport. The hollow core floors and the hollow core walls that were used on this provide sound attenuation from the airplanes and also from the traffic noise from the adjacent freeway. The building was finished with field installed brick. Hollow core construction also alleviates another key concern, fire. Constructed of inorganic materials, concrete offers a non-combustible environment that helps curtail this danger and confine the damage into smaller compartments. It offers up to four-hour fire rating and passes a hose stream pressure test, which minimizes damage from firefighting and water. Smoke damage also is reduced because the walls and floors can't ignite. Best of all, the use of hollow core floors and walls together create a segmented design that better contains fire at its point of origin. This not only helps save lives, it also reduces fire insurance premiums and helps prevent significant property loss. The project here is the Hilton Suites in Shoreview, Minnesota. Compartmentization provides passive fire protection by containing a fire within a single unit and prevents fire spread. The structure was constructed using CMU demising walls and hollow core floor planks. This is a picture of a hotel in the Chicago area that suffered an explosion. While this building was not specifically designed for blast loads, you can see it performed quite well. Note that there's a large portion of the bearing wall that is missing, and it demonstrates the effectiveness of the grouted key joints. In fact, I'm not quite sure how this building is standing up, but it obviously is. Hollow core also offers a sustainable solution for construction. The raw materials are typically locally sourced and usually have a high recycled content. Because of the dry cast method and therefore low water content, as well as an ideal curing environment, large cement replacements can be made with fly ash and or slag. The pre-stressing steel that is used typically has a recycled content over 90%. The concrete also provides thermal mass that helps to reduce the heating and cooling demands. While cement does have a lot of embodied energy and releases a fair bit of CO2 in its manufacture, this amortizes out when considering the long service life of these structures and becomes insignificant when compared to the energy savings a quality structure can provide. This is the Gordon Food Service building in Wyoming, Michigan. The owner wanted to reflect the company's culture and values, which included conserving resources for the future and investing in the local community. To embody these goals, they chose precast for their home office in Michigan and used locally mined and manufactured precast concrete pieces, increasing sustainability and reducing waste on site. Because Holocore is cast at a factory away from the site under controlled conditions, it remains unaffected by the critical path of other construction work. That means that production can begin even before foundation preparation commences, ensuring components are ready for erection as soon as the site is ready. This is the Embassy Suites in Brooklyn Center, Minnesota. Prefabricated steel stud walls, as well as Holocore plank, were used to construct the eight-story structure. Despite the fact that the walls and floors were installed by different subcontractors, which created some congestion and coordination issues at site, the building was erected very quickly when compared to competing systems. Precast components can be erected throughout the harshest weather, eliminating delays that would slow other construction method. These advantages result in faster installations and faster completions, as well as less added cushion in the planned timetable to allow for unknown delays. That leads to less downtime and more control in scheduling other trades, as well as a quicker occupancy, less interest on loans, and other readily measurable savings. This is the Oxbow Mixed-Use Project that was located in St. Paul, Minnesota. The project had two levels of Holocore floors, beams, columns, and precast wall panels that created parking and retail space, and it also has five levels of wood framing for apartments that were put on top of all the precast. All bearing for the floors was provided by the precast so that a single subcontractor was able to install all of the precast without waiting for other trades. This simplified the urban installation of the precast by allowing the crane to be located inside the hole and limiting perimeter access and road closures. The cost-effectiveness of Holocore components is most readily apparent when the building's full lifetime is considered. While Holocore construction may have slightly higher out-of-ground costs than wood frame or other construction methods, savvy builders and developers realize that they must look at the entire life cycle of the building when they're considering what construction materials to specify, and long-term benefits are where Holocore really shines. The lowered long-term requirements for maintenance, insurance rates, and operating expenses make Holocore components a long-term winner. In fact, studies have shown that savings on lower insurance premiums alone can make up the initial cost differential in less than two years. The durability and long life of Holocore products makes its life cycle costs a key advantage when comparing construction options. Now we've seen how Holocore is created and its inherent advantages, as well as the most common types of systems. The next question that usually arises is, on what types of products can Holocore floors and walls be used effectively? The answer to that is basically whatever type the designer's imagination can create. Now let's take a quick look at Holocore and how it's used in two of its most popular applications, floors and ceilings and walls. Depending on the size and location, openings in floors and walls can usually be accommodated or even be cut after the fact on site. The details will be coordinated by your pre-caster in the pre-planning stages. This is a key reason why you should bring your pre-caster into the design stage as early as possible. The project you see here is the Molosky Stadium at the University of Minnesota Duluth. The project was an excellent example of coordination between architect, engineer, general contractor, and pre-caster to figure out how to build this complex structure consisting of pre-cast walls, beams, columns, and Holocore plank. The pre-caster was brought into the team well before construction documents were completed to help solve the many design challenges. 3D modeling was also used in the creation of the shop drawings to aid in the visualization and also ensure accuracy. You can see an image of the 3D model in the lower left-hand corner there. Floors are placed, aligned, and leveled prior to grouting the joints. The slabs have a key joint detail as Clinton described. Once these joints are grouted, the floor becomes a monolithic unit. Cast-in-place concrete topping may be applied to create a composite deck. Toppings over Holocore floors can be used for additional strength to cover over electrical or mechanical runs or as a leveling course for thin carpet and tile direct applications. This is the Cherrywood Point project in Roosevelt, Minnesota. This is an elderly housing facility that used Holocore and pre-cast beams and columns to create a fire separation between parking and living spaces as well as to act as a transfer level for the wood frame structure that was built on top of this floor. Ceiling surfaces may be caulked at the joint underside and flat or textured painted as desired. This is the Munger Graduate Residence in Granville, Michigan. Holocore's other key use comes as wall panels. In this application, it offers an easy-to-use wall facade or partition that is attractive, efficient, and economical. Panel varieties are numerous. The walls can be installed in horizontal or vertical form, and they can be specified as insulated sandwich panels or as solid construction, and they can be load-bearing or non-load-bearing. In this example, sandwich insulated wall panels have been horizontally applied and are non-load-bearing. The interior width or panel face acts as a durable interior surface. Thickness of the interior insulation, such as polystyrene, can be varied to achieve the desired R-value. In addition to the energy efficiency from the insulating layer, the high thermal mass for the two layers of concrete combines with the insulation and the thermal breaks between the materials to create an extremely efficient thermal assembly in summer and winter. Used between living spaces, it boosts acoustical dampening as well. Diverse and beautiful standard finishes can be applied mechanically to holocore panels. Color can be achieved with stains on site, or integral colors and aggregate textures can be applied during the casting phase to create the desired aesthetic results. Glass and other building materials can be integrated easily into the wall cladding to achieve a variety of design objectives. Large door openings can be framed with steel or precast supports to meet the project requirements in a quickly constructed format. Doors and doors can be provided by forming or cutting within a panel or by framing around the desired opening. In single family homes, for instance, holocore components can provide long, clear spans for design flexibility and lofty heights with solid construction. Precast concrete homes will also withstand high winds, fire, and floods far better than typical wood frame construction. This is the North Street Duplexes in Washington, D.C. Holocore slabs can also be used in residential construction to create a basement beneath the garage, which can be used as a workshop, home theater, sport court, or other uses. At Moline, we supply 250 to 300 of these every year. Hotels and motels can be built fire safe, private, and secure. This is the Fenway Residence Inn by Marriott in Boston, Massachusetts. Student housing can enjoy improved sound control, better life safety standards, and superior durability for the walls and floors. This is Lincoln University student housing in Pennsylvania. A type of building that is common in Minnesota, as well as many other parts of the country, is podium construction, where three, four, or even five stories of wood-framed apartments or condos are built on top of a precast and holocore frame. The holocore serves as a fire separation, as well as a load transfer level between the living units and the parking or common spaces below. This is the Onyx mixed-use project in Edina, Minnesota. It contained one and a half levels of parking, retail, and some amenity spaces. And as you can see, there's five levels of luxury apartments that were framed on top of that, and there was even a swimming pool that was constructed using holocore planks. Senior citizen housing can offer its residents peace of mind due to quiet, comfortable surroundings and excellent fire protection. This is the Woodlawn Senior Housing Center in Chicago, Illinois. Housing with even more stringent requirements, prison facilities, or other shelters can benefit too, because of holocore's economical construction, high durability and security, fire resistance, and quick construction. This is higher ground in Minneapolis, Minnesota. This is a transitional housing facility. Holocore ceilings and floors were left visible for a modern look and more affordable finishing. They also reduce sound transmission and meet the required two-hour fire rating. Office buildings offer an ideal use for holocore walls and floors, because they can ensure privacy between floors and adjoining offices. In addition, they provide security and fire protection that companies find comforting, making it easier to attract tenants. That added layer of security and durability makes holocore an excellent choice for schools as well. Applications in municipal, state, and federal government structures are varied. Buildings using holocore components include such diverse facilities as public works garages, fire stations, city halls, storage sheds, utility buildings, park shelters, community centers, schools, gyms, and sports stadia. This is the Glenview Village Hall and Police Station in Glenview, Illinois. Hospitals too can benefit from additional privacy and a strong, solid image. Holocore products further aid medical facilities by providing great adaptability to heavy and varied loads, equipment needs, and medical environments. A host of retail owners are also taking advantage of the material. This three-story car dealership in Minneapolis utilized holocore for an open concept design. Shopping centers and mixed-use facilities offer a prime candidate for using holocore floors and walls. Not only does the material help them project an attractive, solid image and bring the project into use quickly, but the centers enjoy lower insurance rates and better protection from break-ins. This is the New Brunswick Gateway Transit Village in New Brunswick, New Jersey, which was constructed using a steel frame and holocore and has a residential tower with 150 apartments and condos over a retail space. Other types of projects also benefit from the use of holocore walls and floors, especially those requiring regular and thorough cleaning. Precast walls and floor panels can be cleaned easily with high-pressure hoses or other harsh cleaning equipment to ensure they remain spotless. This is vital for agricultural facilities or animal shelters, for example, which must be cleaned and resist corrosion from continual exposure to moisture. This is the Midwestern University College of Veterinary Medicine in Arizona. Food processing plants offer a booming market for precast holocore products. These facilities must be designed to offer no horizontal surfaces, as well as a smooth and impenetrable surface in order to eliminate any places where dust, dirt, or other contaminants could accumulate. They also have hot, moist environments that can corrode other materials. The ability of precast holocore components to create both a structure and a solid interior surface which withstands these demands has made it the ideal solution for food processors of all types. Municipalities are also discovering the benefit that holocore components provide in supplying sound walls for highway applications. These components offer an attractive, low-cost, long-lasting, and effective solution to reducing the highway noise in surrounding communities. As with other types of projects, sound wall applications do not need to wait for warmer weather. This ensures they are installed as early as possible to aid nearby residents. You've now seen and heard a brief explanation of what holocore panels are, what their key benefits are, some of their key installation elements, and the types of projects where they are most commonly used. The final question we'll answer today is how do you start building and designing with holocore products yourself? First contact your local PCI-certified holocore producer as early in the specification and design stage as possible. Make use of their details and design aids. They will work closely with you to lay out your project and help you take advantage of the economical benefits that precast concrete can create. Most producers can provide a budget price after reviewing any preliminary project design. Connections to panels, foundations, framing, and roofs are varied and depend on conditions. Many of these details are predetermined by the nature of the precast system and the precast manufacturer. Your local precaster will ensure that the components you desire will connect effectively and efficiently using the most recent technological advances and designs. Once your contract is awarded, the selected precaster will convert your plans into detailed shop drawings. The architect and engineer will review, modify, and approve these details for final production. Every award of the contract ensures adequate time for engineering, production, and coordination with other trades. Here again is a list of some of the many benefits precast holocore planks and walls can provide for your project. These benefits add up to both considerable cost savings during construction as well as for long-term. They also ensure that the building remains attractive through its service life, helping to keep it occupied, and producing revenue. For more information or to find the location of a PCI-certified precaster in your area, contact the Precast Precast Concrete Institute or visit their website, PCI.org. The results will help you determine how you can best take advantage of the inherent benefits available in precast concrete holocore components and how to realize the maximum cost savings to create an aesthetically pleasing and cost-effective design. This is where our presentation ended on Tuesday, and we had a little time extra, so I thought I'd add a couple more slides and take the opportunity to perhaps get on my soapbox and share a few thoughts with you. In doing that, I'd like to go back to this photo we saw earlier. This is a podium-type structure where you have five levels of wood on top of holocore. This is a quite common construction method, and we do a ton of these. It's good work. It puts food on my table, but when you think about the wood structure, you have five levels of wood coming down here, and it's got a lot of openings in it, so at the end of the day, there's not a lot of insulation left in these walls. I just wanted to share with you some slides from the other side of the world. This picture was taken in Finland, just outside of Helsinki, in a place called Buisari. I've had the opportunity to go over there a few times and see some precast. PCI actually paid my expenses to go visit with the FIB Commission 6, which is similar to PCI in that they write documents on how to design with precast, so I've attended their conference on a number of occasions. One day, I had an extra day to kill and jumped on the train and went to Buisari and saw these multifamily housings. Here's another example of that. What you see in white is an architecturally finished architectural panel. The part in gray was going to get finished with a plaster in the field, which is what is on these buildings. Here, you see in yellow. These panels you see in the upper left corner is the insulation that was used there. I was in the factory where they made these panels a few days prior to this, and that insulation is six to eight inches thick of mineral wool. The windows they put in here have four panes of glass in them, so you could heat these things with a couple of candles, most likely. I kept on walking and just saw building after building. Every one of these is 100 percent total precast construction. I had an opportunity to talk to a gentleman in the construction industry there and asked what percentage of housing in Finland was done with precast, and the answer was 99 percent. I just thought I'd share with you these. There's a variety of different finishes and looks. It just went on and on and on as far as you could walk. It's amazing that there's that many people that want to live in apartments that close together. There it is. Just one last photo here, which obviously is not precast. This has been there a while, but I guess the message is don't be afraid to build quality. Your great-great-great-grandchildren will thank you someday. Precast can help you provide a long-lasting, durable structure that's energy efficient and sustainable. That's all I've got. I think we still have some time for some questions.

Holocore Floors

Holocore Walls

high-strength concrete

load-bearing walls

insulated panels

fire resistance

sustainability

Precast Concrete Institute