is yours. Great, thank you very much and good afternoon everyone and thank you very much for joining us today as we're going to explore and talk about the aesthetic versatility of precast concrete. First we'll go over kind of our learning objectives here. What we're going to do is we're going to talk about the different finish options of precast concrete and the various methods we can use to achieve color, form, and texture. Now this is going to provide an overview but it's going to go more in-depth in these areas and we'll even make some recommendations and some things to consider as you're considering you know what what you're going to apply to a specific project. So obviously we want the best results for that project. We'll also talk about clay products and natural stones and how they can be veneered or in some cases embedded into precast concrete. There's some advantages to doing that of course. It's going to help reduce costs etc. And throughout this try and highlight several projects. We'll talk about some of the latest innovations and some of the kind of innovative uses and applications from an aesthetic standpoint of precast concrete as well. So with that hopefully on your screen you should be able to see two fairly well-known structures, somewhat iconic structures we could say. We've got the Baha'i Temple over here and of course the Transamerica building in San Francisco. Now both of these though are actually cladded in architectural precast concrete and not everybody knows that but they kind of show I think some good examples of what can be accomplished. These are obviously much older structures and so this goes back quite a while now. But as you can see let's take the Baha'i Temple for example there's a tremendous amount of ornate detail in that structure. And so as designers when we kind of push the envelope we really can do quite a bit with this material and that's part of what we want to highlight today. But before we go into great depth we're going to start at the beginning. We'll get kind of basic for just a minute because no matter what material we use it's really important to have a basic understanding of the fundamentals of that material, what affects that material and again we're really referring to aesthetics today so what affects the results of the aesthetics, how are we going to be consistent aesthetics with it to meet our program goals basically. So let's start by asking that fundamental question you know what is concrete and and you'll see a variety of definitions out there. This one I pulled from the American Society of Testing Materials or ASTM International. It says composite material right that consists of essentially a binding medium within which are embedded particles or fragments of area. That's correct. The part that I want to highlight to you is that it is a composite material and that means basically the raw materials to go into it are really critical because it can only be as good as those raw materials are and in the process of manufacturing it. So quality control is obviously going to play a very important role in getting to our end results that that we desire here. So let's take a look what materials are we talking about. Well we're looking at cement which is of course the binding medium in concrete. We're talking about water which when combined with cement a chemical reaction takes place called hydration and we'll discuss that a little bit because it's actually very very important to achieving the aesthetics. And then of course you have aggregates which are going to be your sand and your stone and in most cases today we do use chemical admixtures in a lot of the concrete between air entrainment and a variety of other things such as water reducers to improve durability and improve workability and things of that nature. And there's also air in concrete as well whether it be air entrainment or freeze-thaw durability or we're talking about just some entrapped air in there. Essentially there is air in all concrete. So if you follow the logical progression for a minute then what is precast concrete? Well in a generic sense it's basically concrete that is cast elsewhere than in its final position. That's what ACI defines it as. So a lot of things under this definition really qualify as precast concrete. An example would be tilt-up. You know some people will call that site cast precast. However today what we're focusing on is the plant produced precast concrete. These are made usually in PCI certified plants and what we'll see is that quality control afforded to those operations is critical in achieving the results that we're looking for here especially again we're focusing mostly from an aesthetic standpoint today. So again we're all about plant manufactured precast concrete manufactured off-site then delivered kind of like a just-in-time delivery. So something else we want to tie in real quick is you hear a lot about this today high performance, high performance structures, high performance materials and there's a lot here to look at but we should have a basic understanding of what do we mean by that. So how do we define a high performance structure? Well the federal government has done this for us and in a quick summarized version basically is a high performance structure is one that integrates and optimizes on a lifecycle basis all major high performance attributes and then they continue to list as you can see here a fairly extensive grouping of these attributes from energy and water conservation you know through security durability all the way to taking into account really the operational considerations of a project. Now all this is a again kind of a broad high-level definition. There's three components to it I want to point out that we should be cognizant of. The first one is notice that sustainability is actually part of what they're considering the various components of high performance. So in other words high performance is broader than sustainability it encompasses everything we've been talking about for more than a decade now in recycled materials and in looking at sustainable practices environmental impact you know and so forth. That's all part of this this is even broader and encompasses more than just sustainability and then that's important thing to not lose sight of. Another really critical component is this that it integrates and optimizes and here's that little word we slide in it all major high performance attributes. That's a little bit of a shift because in most projects it seems there's a couple things that really drive it a good example is schedule. We have a tight schedule we've got to make sure we this opens on time and so that drives some of our decisions in some cases a lot more but overall some other areas kind of can get ignored a little bit and high performance challenges us to look at all of the relevant attributes for a project and to work on optimizing all those relevant attributes for a project and then finally we notice here that there's a shift from just looking at first costs to kind of making a challenge to look at lifecycle costs and long-term performance and long-term effects from the from the design and the structures that we build and this this may change our decisions you know what would we do differently when you start thinking about something lasting 50 60 70 years and in doing an analysis on lifecycle costs you know what materials would we use different what would how would we design differently for those things so as we go through our discussions today keep these three key components of high performance in mind now in terms of precast concrete we say that precast concrete is a high-performance material it integrates easily with other systems and inherently provides versatility efficiency and resiliency that's going to help us meet our high performance requirements multi-hazard requirements long-term demands etc now in this definition there is one word here also want to really highlight and that's inherently it inherently provides the versatility efficiency and resiliency and really what that means is you're getting an awful lot when you decide to go a precast concrete there's a lot of attributes and there's a lot of things that translate to benefits the question starts to become is do we understand them how do we optimize designs to take advantage of them or do things just get left on the table and so some of that will be evident as we go through the presentation today this is a quick summary of all of these different attributes and they're just organized here under the three categories you know versatile efficient resilient you can get a quick feel for the types of things that are there and like I said most of them are really inherent in just saying hey we're going to use precast concrete but our conversation is really going to take into this now we're going to talk about the aesthetic versatility and get into things that contribute to them and and how we can best you know optimize designs to achieve those goals so the first question is what do we mean by that what what is aesthetic versatility how would you end up defining that well basically let's say we're using materials that first of all provide us a lot of well versatility right virtually any color form or texture there's a lot of advantage to that if I learn one material system and it gives me that option there are many options then I don't have to learn other material systems in fact maybe it can do the job of several different materials in an application and that's going to help us reduce complexity and a lot of things also facades or really envelope systems are made up of many different systems of materials so we want to work with things that actually can integrate well if the other systems and aren't going to cause us headaches down the road and precast does a really good job of that in fact if you really do the analysis on the entire envelope you'll see that it really contributes to more of the other systems such as vapor barriers and thermal protection and things like that as well more than just the aesthetic side and then another component really is to take a look at historic context because quite often we're designing structures that have to fit in with an existing architecture maybe on a campus or in a downtown even some of those materials might not even exist anymore but somehow we have to make this blend I know that's a challenge for many of you precast gives us a lot of versatility to do that to meet the historic context basically and allow us to achieve those goals so a logical question becomes well what can you have a high-performance aesthetic material and what would that be well I think right off the bat we would say these materials would have to provide aesthetic versatility right materials that can provide more than one thing do more one thing are really high-performance materials you want to be efficient with things but you also want to look at how these materials are used in designing construction when we think of versatility really are focused on the design phase and a little bit on the construction phase of the project where engineers and architects have to deal with things so are they minimizing construction complexity how are they affecting long-term lifecycle costs you know for example reducing joints how they affect maintenance things of that nature so precast is what we call a face sealed or barrier wall system and if you compare that to really the main alternative which is cavity walls or rain screen systems precast is less complex I'm sure all of you have designed and detailed those systems and and there's more work that goes into it there's more construction sometimes multiple trades and at the end we really hope that what we've designed is exactly what's getting built on the project site and that it's not going to lead to future problems and being a face-sealed system that does reduce complexity and allows us to achieve that a little more easily materials that are durable right things that are going to be around I mean we don't want to replace the facade every 10 or 15 years so we want things that are going to last and well precast concrete is one of the most durable materials we have has a very long service life and then finally materials that also contribute to other components because you saw really when you're looking at high performance it's not just about one thing we want to optimize all the attributes so that means the efficiency of the project as well as the resiliency and long-term durability of the project so for example if you're working with a precast concrete envelope system it has an inherent ability to resist impacts and high winds and storm damage and things like that saving lives whereas some of the other building materials we've seen in in our industry don't necessarily do that good of a job at that so it starts to give an example of how these things combine together to reach really that ultimate goal optimizing all relevant attributes so in terms of aesthetics usually if we look at the two ends of the spectrum well on one end we probably have something like the historic context we got to blend in things got to be usually traditional materials like bricks and stone and stuff like that this is a dormitory on an Illinois campus and again kind of historic what you'd expect maybe a traditional dormitory to look like in other cases we want to design structures that really stand out maybe they're iconic maybe they're making a statement for a company or campus this is this another campus this is Penn State University and this is the new millennium complex two actual science buildings that are coming together here but it kind of shows a precast can really achieve either end of the spectrum from an aesthetic standpoint and of course anywhere in between now there's some basic terms that we'll be discussing and we want just define them so we're on the same page first color it's just a reflection of light waves right but we have to remember that color is influenced by a lot of things the finish that we choose the shadowing and lighting effects is it a cloudy day all those things are gonna gonna affect really how color is perceived then you have texture which is really the surface characteristics or the exposure of that surface that we're talking about on the finish as well as then when you combine these you really get to what we're calling the finish the final finish of that particular envelope material facade etc and then form and can do this in two ways you can always look at form as the structure as a whole right as we put all this together all these parts what form does it take but it also can refer to the individual parts and the details of those parts what forms can we make basically precast being a very well multiple type material it can make pretty much any kind of form now to highlight this you can see here this is a close-up of a precast panel you can see color and texture here the colors my screen at least it's kind of grayish and it seems to be kind of a weathered texture obviously looks like some sort of a block line but when you step back and we see this now actually applied in the structure this is a library in Jacksonville Florida it takes on some different characteristics you can see how it comes together maybe the color looks a little different the overall finish starts to look at a little different stuff and those things are parts of what we consider to and design how are things going to look at a distance and up close now in terms of aesthetics and the colors how does concrete get its color well you really you're getting it from the raw materials so you're either going to use aggregates as we see over here on the right or you're going to end up using what we talked about in a minute the paste or the cementitious content and you can see there's a wide spectrum of that here just to kind of highlight what can be done with pigments and the paste portion of concrete this is a replica obviously the US flag this thing stands 16 feet tall my company built this well probably two decades ago but we use pigments to achieve the dark blue here and the red and then of course a white cement mix to really finish this out and it's actually a pretty interesting replica all 50 stars they're all 13 stripes if we could catch it in profile you'd see it actually has a wave to it and everything like that and it just I think gives an example what really can be accomplished in detail as well as in in color so as I said what's contributing to concrete color well you have paste this is really important we're talking about hydrated cementitious materials here that's cement and supplementary cementing materials okay mixed with water that's a chemical reaction we call it hydration whenever you have a chemical reaction there's a lot of things are going to influence it from temperatures to curing to the ingredients themselves and we'll talk a little bit more about those but we have just remember for now chemical reactions can come out different time and time again so quality control becomes extremely important then you have the matrix which when we say matrix are really referring to fine aggregate or sand combined with the paste which is sand is defined by something that passes a number four sieve then you have coarse aggregate which is your stone obviously doesn't pass a number four sieve and in some cases you might have coatings such as paints or stains or something of that nature where you know maybe it's going to be applied to put a color on a particular structure things like that sometimes you might see that for example in a warehouse area in terms of texture and exposure we're looking at really the exposure of the aggregate here okay so when you hear that word you want to think well how much of my area is being seen or contributing to color and it varies all the way from what we call none or or skin which is a very fine film of paste if you would come comes that way out the form basically all the way down to as you can see deeper coarse aggregates are predominant so when you hear light for example you can see down here in the bottom section here this is really a light exposure there's little bits of the sand starting to show through with the paste medium which we have really two examples here at the top and the side roughly it's a 50-50 mix of the matrix you're seeing more of the coarse aggregate but you still see quite a bit of the sand in the paste there now those are two different techniques we'll talk about now they're achieved but you can get a feel for it whereas when you get to deeper aggregate exposures of course aggregate is predominant I mean these are very different it changes the color obviously the texture and and it's the coarse aggregate that it is contributing to that color now there's a wide variety of textures and finishes out there we're going to talk about just some of the most commonly used ones today the first thing is if you're going to use concrete as the finish which a lot of people do then you have different techniques such as ass cast another name for the form finish abrasive blast acid etching exposed aggregate and that's a little different because we're using chemical surface retarders or polishing techniques that's not all we have you can also get into as I said the embedded and veneered materials we'll talk briefly a little bit about what cast stone is and then we'll of course going to talk about the form work and form liners because they're going to really contribute to what we can develop in the shapes of our pieces so let's combine these for just a minute to this is not a gospel but this gives an idea an example of the most commonly used techniques to achieve certain levels of exposure so obviously for example if you're going to do a skin or you know paste only you're talking about a form finish that's an as cast finish whereas as you're going to get into your deeper aggregate exposures okay most of the time that's done through abrasive blasting or through an exposed area procedure it should also be done through polishing a common one we've seen acid etches to go deeper but again not gospel but most of the time acid etches are used for lighter to medium exposures so always the best way to deal with these things is to have a conversation with your precaster they're going to know really the best options for your project because every project has a lot of unique aspects to it and so they're going to serve as a great guide on what finish and where do we start and stuff like that now I want to put these into two groups for the conversations going forward one is a finish is either driven it's color excuse me is driven either by a paste dominant color think of those as the exposures from basically none to about light you know just boring a little bit of medium exposures, and the aggregate-dominant colors. Those are the ones driven by the aggregate, and that's gonna be at your heavy exposures, medium to heavy-type exposures. So let's explore these different finishes a little bit closer. This is an example of ASCAS. These are form-finished structures. You can see a variety of them here. In fact, one of them I'm sure you'll recognize. They're the Perot Museum. It's pretty popular right now. Some great work here. You can see the beautiful details that can be achieved from, well, it's kinda highlighted here on the Perot Museum. This is an economical finish, right? You're just pulling it out of the forms. Anytime you can reduce the amount of labor that is going into a finish, it's gonna be more economical. However, you do have to realize that since this is being driven by the paste only, really, on these surfaces, panel-to-panel variation is most likely going to exist. Paste picks up moisture. It also is a little more susceptible to the environment around it, so that means it can dirty. For example, etched a little bit by weathering. Those are things to keep in mind. You're also gonna have more modeling, meaning within the piece, color variation. So, and a lot of times, this is used. You see gray in really all three applications. Let concrete be concrete kind of approach. Most people think of concrete as gray. Now, these are pretty common finishes here. This is our acid etching and abrasive blast. Abrasive blast is usually done with sandblasting in most applications, not all. The top one here, you can see, this is more of a medium getting into the heavy abrasive blast. Important to know, this is gonna usually lighten the surface, lighten the color. It kind of gives a frosted appearance. It's abrasive, so it abrades away. Aggregate and surface gives you kind of a smooth finish. This acid etching down here, usually done with muriatic, excuse me, muriatic acid, is, again, used for lighter exposures, medium exposures. It typically darkens the surface and also has kind of a sparkle to it, like we see with some natural stones, sometimes called a sugar cube finish and so forth. So there are differences there. Typically, in terms of color, both of these are pretty good. Deeper exposures usually are going to help us hide imperfections, resist weathering a little bit more over the long term. Obviously, acid etch, for example, is gonna be good if you have an acid rain environment or factory environments close by. Deeper exposures minimize, like I said, variations and improve weathering characteristics long term, usually. All those kind of things you want to take into account as you get into the design of this. One thing I do want to highlight here is this is the same mix design. So from an economical standpoint, one mix design, one concrete's being poured, but by using two different finishing techniques, I do get two different colors, two ultimate different finishes here. This is just another example of the acid etching, and you can see here, this is a little bit deeper. A lot more of the aggregate's starting to shine through. This is a form liner they use to get kind of this, you know, the rough chiseled form liner stone there, basically, and then here's another example. This is an abrasive blast. They did both some light abrasive blasting here as well as some deeper abrasive blasting on the dark sections and so forth. And then we have exposed aggregate. That's just a term we use in the industry. This is different, though. This is accomplished using a chemical surface retarder. It's either sprayed or rolled into the forms and retards the setting of the cement. So the next day, next morning, usually, you pull these pieces out of the forms and use, commonly, a high pressure washer, water, to blast away that cement and exposing the aggregate at different levels. A couple things. The aggregate here is pretty natural this way. Okay, there's no abrasion. There's nothing changing its color. So it's gonna protrude. It's gonna carry on its regular shapes and colors, and that can be very valuable in some applications. I wanna also highlight that usually these mixes are gap graded. That means that they don't follow ASTM C33 to the letter. They need to remove certain levels of stone, certain sizes of stone. So that you get this nice, tight matrix in there, and as well as you don't want small pieces of stone falling out when you water blast it, and then you lose that, and you start having a lot of voids in there and stuff. So that is common and quite often will be done. Now, when you compare these, this is another example of an exposed aggregate, but specifically, we have sandblast here on the bottom, exposed aggregate on the top. And this is a good comparison because you can see same mix design, two different colors. Note again that the abrasive blasting wears away and surface gives you a smooth surface, whereas an exposed aggregate through surface retarder retains the color, retains the shape, gives you a rougher surface here that you're gonna see in touch and exposed. Some applications, we use these to mimic granite. In this case here, you can see they used a couple different versions to basically mimic our flame-finished granite and polished granite and stuff. Both of these are exposed aggregate finishes. But you can use a little bit different technique too, which does a great job. And that's called polishing. This is essentially like it sounds. We're grinding and polishing the surface, and it's very smooth, just like you'd see a polished granite, shiny. Does a beautiful job. This is the Minneapolis Convention Center here. And they use this throughout the entire convention center, inside, outside, Wayne's Co. throughout the building. And as you can see, it's really a beautiful finish, a great alternative to using granite in some applications. One thing to keep in mind, from a cost perspective, this type of an approach, being more labor-intensive, might be more expensive than like a sandblast finish, but it's obviously gonna be less expensive than using usually like a real granite or stone application. So it just gives more options. Here's a couple of other buildings that you can see, kinda highlights the dark banding here, where all polished materials on there. They look pretty nice. Now let's talk a little bit about embedded and veneered materials. These are natural materials in precast concrete. And as you'll see, there's a lot of obvious advantages to that. The most common one is what we call embedded thin brick. So first of all, this is real brick. This is clay brick. It's just reduced in thickness down to maybe, let's say a half inch or five eighths of an inch thick. If you look close here, it's keyed in the back. So there's grooves or some sort of keys in the back of these. And then it's put into form liners. Most architectural precast bases cast face down and the concrete is cast right to it. So it's actually cast into or embedded into it. Now, this comes in essentially today, just about any color and shape that any other field laid brick would come in. And you can really do just about anything with it. Any patterns, different types of stack bond, running bonds. You can do detail work, put in headers and soldier courses and things like that. So it gives you all that same versatility, but of course with a lot of added benefits to it as well. Now up in the top here, you can see, or excuse me, San Francisco Museum of Modern Art, a little older structure, but a beautiful building. This is all precast concrete facade, embedded brick. A little detail here, actually, here's probably a better picture of the detail here. And you can see in this case that you did use some full brick to get that level of detail embedded into these panels and stuff like that. And some jobs are done that way. The technology has come really far today and offers a tremendous amount of options in there. So for example, here's two other structures with embedded thin brick. The one at the top, this is the Colt Stadium in Indianapolis. Beautiful, beautiful brick works, all thin brick precast embedded, excuse me, embedded thin brick on precast. And you can see we've got arches in there and different details and stuff that are obviously even more challenging and expensive sometimes to do in the field. Well, almost always more expensive, but. In terms of another example here, this is the Sanford Hospital up in South Dakota. Another beautiful project. As you start to look at these, you can see that the designers have done an excellent job of even hiding panel joints and kind of applying them into where, well, applying them right into the architectural design of the structure. So you really don't even see those anymore. And again, precasters, they're a very good resource. They have a lot of different ways to help you achieve your design goals and mitigate any kind of concerns with it. But you can do a lot of other things in veneer. You can do granite and limestone, for example. However, when you get in some of these natural stones, these are not usually embedded. These are more traditional veneered materials. They're applied usually with some sort of clips or pins, typically stainless steel pins that are gonna be embedded into the concrete with a bond breaker between the material. These are also usually larger sections of stone. So that can be beneficial. Like take this library over here, I believe on the right. And you can see these beautiful curved sections over there. That's a lot easier to do a precast than that would be to try and have to actually deal with that in the field. You can also do marble. Glazed products are being done. There's an office building down at the bottom here in Ohio that used tremendous colors with very glazed products. You can also see terracotta today. And the use of terracotta has actually expanded quite a bit. Both of these projects are a little newer projects here. This one on the bottom, this is a parking structure up in the New England area. And that's terracotta that's been embedded into, those are structural wall elements. And if I've been told correctly, that's one of the first applications of structural wall elements with terracotta. So there's a lot of benefits to this. You say, well, okay, why would we do it this way? Well, let's take a look at some of these. First of all, it really does simplify design. If you think about it, the materials are being trans, they're, excuse me, the finished materials themselves are transferring loads into precast, which means all of that weight is being transferred back into wherever the bearing points are for the precast. Makes it a lot easier to handle that loading, allows for multi-planes and curves, accomplish difficult shapes like we saw there with curved pieces and stuff like that, radiuses, arches, et cetera. It obviously is gonna save a lot of time. I mean, we used to joke and say, well, with a thin brick veneered panel, you can set 400 square foot of brick in about 10 minutes. That's impossible to do by any other means. And so you're going to have a faster project. Obviously weather delays and considerations like that are going to go out the window. You don't have to worry about those things. It reduces site impact. There's no storage or staging need. All these materials are shipped to the precast yard and are installed at the precaster's facilities. So you don't have to deal with that, nor do you have to deal with scaffolding, like I said, winter construction covering things, stuff like that, all goes away. They're very durable materials and they help reduce the overall lifecycle costs. So for example, with that thin brick, what's between those joints is no longer six and 700 PSI mortar. Now it's five and 6,000 PSI concrete. So it's going to be very durable. You're not going to have tuck pointing issues with that in the longterm and a lot of maintenance issues. You're actually reducing the total number of joints in any of those systems relative to using them in some of the traditional field applications. Instead of having multiple contractors, in a lot of cases, you're reducing the number of contractors. You don't have stone masons and brick masons working together. I mean, a lot of, again, this is all done at the yard and stuff. And the precaster takes care of that. And then of course, in most cases, the precaster does the erection of the pieces as well on site. And I think one other thing you could consider is that in most of these applications, you're reducing the material itself. They did a project in Florida a while back and it was a dormitory project, if I remember correctly. They did a comparison between a field laid brick application and a thin brick application. They ultimately went with thin brick. But on the comparative analysis, they learned that it was really saving a lot of energy and materials. For example, it was like over 1,100 tons of material. Think about thin brick compared to the size of a regular brick. Over 12,000 gallons of diesel fuel. I mean, you don't have to ship this material. You don't have to quarry this stuff out or you don't have to use the fuel to fire it basically. And that actually resulted in a lot of cost savings too. And I think in that application was somewhere around 70 or $80,000 in cost savings. So there's a lot of things to take into consideration when you're looking at veneers. Now, there's something else I wanna mention. It's called cast stone. And this can be done two ways. One is a wet cast application, which is how most precast is made. Concrete of a higher slump or a self-consolidating concrete put into forms. In some cases, a dry cast application, which is basically it's a very low water cementitious ratio, a granular substance and tamped into the forms. And that process has some advantages too. It does produce very crisp and clean edges and details and stuff like that. No bug holes or anything like that nature. In both cases, it's usually a light acid etch to it to give it a sparkle and clean it up. And cast stone is used in a lot of different applications. You see some examples here, but it does a great job of emulating limestone, sandstone, things of those natures. So now let's talk a little bit about the forms and form liners. Because obviously, precast concrete is made in forms and at the facility. Most of the time, those forms or molds are gonna be wood. They can be made out of other materials such as metal. Maybe you can see concrete used as form work. And it allows for a lot of detail, a lot of ornate detail. I mean, this example here, you can see they've actually put imagery right into the side of the building. You obviously see letters and signs all the time inside of buildings and things like that. And it gives you a lot of flexibility. Here's an example. This is a newer project. Let's see, this is actually the Science Classroom Complex at Florida International University. A very large project here. But the form work is incredibly detailed. Look at the deep recess on these windows here. I mean, basically, they designed in projections that are gonna help meet the shading and energy control requirements for these windows. And took a really extensive form work and a skill to do something like that. The other thing they did here, which is interesting, we talk about integrating systems and materials together. These windows were installed prior to erection. So you didn't have to have people going up to floors and scaffolding or some sort of lifts. All at the facility. Now, a couple points about form design. And again, your producers that you work with more than happy to help you really understand this and come up with the best design to optimize your project. But you need some sort of positive draft on these. We don't wanna damage pieces and we don't wanna damage forms. In fact, the more forms can be reused, obviously, it's going to reduce costs. So this just gives some examples here of the relationships. You've got minimums, but really, you wanna try and increase these a little bit, get down to one in eighth or one in the sixth when you get into detail patterns. And you can see in this example here, as we get deeper in or into smaller reveals, that we need a little bit more of a positive draft there. Because again, you don't want any binding on these materials. Now, reveals, basically a demarcation feature quite often used to develop different patterns and designs. Great way to hide joints by creating false joints and things like that. Commonly, you wanna make them a little wider than deeper. Same concept, we don't wanna get anything bound up in there. You don't wanna damage the piece. You wanna preserve crisp things, crisp details in the precast, et cetera. So it is an option in there. We'll see another way that these can be used here in a moment. Now, another aspect of dealing with aesthetics and form work is the returns. So there's two ways to do this. You have the side of the piece, and of course, you could actually be turning maybe a return back into a recess in the building or turning a corner or something like that. Here's what you need to keep in mind. Precast is cast face down, and if you start using, let's take the example of the aggregates. If you're using an elongated, like a crushed aggregate, gravity's gonna have an effect on that, and it's kind of represented in these pictures. You're gonna see that here. They're gonna align themselves in a certain way. So now if I go with a deeper exposure, the aggregate's gonna take a whole different look on the face than it is on the return side here, and that's why they sometimes recommend using lighter exposures in there or getting into the rounded spherical aggregates. Typically, if you're gonna do more than a 12-inch side or return, you might wanna move over to what we call composite or sequential casting, which is basically casting something face down, and then the next day, this is set upright and cast into the second piece this way. So both surfaces are cast face down that way. There's other ways around this. For example, you could just create a mitered joint between two panels instead of having it completely return around the building. When you talk with your precasters, again, you're gonna get into project specifics that'll make it more clear what probably makes the most sense for a specific project, but you should be aware of these things so you get the right results. Of course, you can get into form liners, and these are growing tremendously in popularity today and all the different options out there, commonly used for repetitive patterns, commonly used for things like trying to emulate stones or wood or different types of rib systems, things like that. We saw an example earlier with the brick liner. They use form liners to hold the bricks in place, things like that. When you combine it all together between form liners and form work, you really can create some amazing details and projects and really give unique characteristics to the projects you're working on. And here's just, again, a couple examples to try and highlight some of those ornate details and stuff. Now, putting all this together, there's something else you really can consider to get the desired aesthetic results, and that's combining different finishes and colors and techniques together into one panel. And you can see here, I mean, this one example's got different materials. We've got granite at the base, we've got thin brick up top, and then we've got exposed precast with a light acid etch on it, whereas the other one, it's all precast, but they're using different colors and finishing techniques to achieve that, all combined into one panel. There's a lot of benefits to doing this now. For example, you're gonna reduce joints, detailing, and again, whenever we can reduce construction complexity, we're headed down the right direction. So for example, you look at this piece over here, thin brick, this is actually a form liner they used in some pigments to achieve that stone look. There's no flashing or detailing around this sill and trim because it's all monolithically cast into one piece. Now, that reduces construction complexity. You're also, at the same time, you're reducing the number of trades. Again, like in this case, there's probably at least two, maybe three trades at work on this particular piece. Now, it's all monolithically cast in one panel. If you really wanna start talking about the whole envelope design, then you get into, if this had continuous insulation in it and precast provides you a continuous air barrier and vapor barrier, now you're eliminating other trades and really kind of optimizing the envelope system overall. And also, it helps reduce maintenance issues, okay? Less places to fix, right? Less joints, less flashing, no tuck pointing, things like that. So you put it all together, it works pretty well. Now, a couple points though. When you're using combination finishes, first of all, you really need to separate these with one of the reveals, okay? You want a real clean stop between one finish or color or material and something else. The other thing I strongly encourage is you want some sort of a difference between the finishes that you're using. So for example, using a light acid etch and then trying to use maybe a medium exposure acid etch, that's not much of a difference, and chances are the variability that's going to overlap will skew that. So you really want to consider, geez, can I use a different color like they did here? Can I use two different finishes like we've seen, or maybe one's an acid etch and one's a sandblast or a braceblast? Can I use different materials? Maybe some of it should be brick or stone or something like that. And usually those end up producing pretty good results. So now let's look at a couple considerations related to accomplishing our goals. First of all, like I said earlier, when we're talking about paste-dominant finishes, things that the color is really being contributed from the paste, we've got to remember about the cement and hydration. They said hydration is a chemical reaction, and what's going to affect that? You've got to make sure all those things are in play. We highly recommend using white cement, especially for any pigments or light finishes, obviously. White cement is consistent. There's actually a color requirement with white cement, where gray cement there is not. You can use supplementary cementing materials, however, from the aesthetic standpoint, things like fly ash, for example, again, no color control. Usually not used, whereas some of these other ones, like a white silica fume or a metakaolin, more control and get you the benefits of an SCM without having a negative effect on the color. If you're using pigments, which is quite common, remember, they're inert, they're not part of the cementitious material, but there's quite an extensive option line there. For example, there's a whole bunch of colors now in pigments that you can see here, and actually their forms have changed a lot. When I was a precaster, we ended up just using powdered pigments at the time, and now we've got things like liquid dispersion admixtures, which produce very consistent color, much cleaner and easier to work with. So you have a lot of options out there, especially, again, when you're talking about a paste-dominant color mix. Here it kind of gives you a full range, gives you a quick example of, well, the various colors that are available out there, and how you can maybe, I mean, pretty much spot anything here in terms of color. Some other considerations, like I said, hydration's a big one, because I can batch two batches of concrete and change one of the variables and end up having a slightly different color. So for example, water-cementitious ratio, the amount of water that goes in relative to the amount of cementitious material, cement and SCMs, that's a big deal. Precast facilities are designed to really monitor and control that on a regular basis, which means you have a much higher probability of getting a consistent color out of a facility designed and certified to manufacture precast than you ever would in the field. Another component of this is curing, which is really just the facilitation of that hydration process continuing on long-term. Now in a precast facility, not only can you control this better, but precast comes up to strength very quickly, because we have to remove it out of the forms essentially the next day. So you're already at your 3,000 and 4,000 PSI strength that way, it's an environmentally controlled space, etc. The other thing, though, is if you cure something different, you can change a portion of the color. So a simple example is if you have a piece of concrete somewhere and it's fairly fresh, right, and you set some sort of an item on it, maybe some cardboard or something like that that traps more moisture in one section than the other, you could end up with a slightly different look there for a period of time, because it's curing differently. So you keep both of those into account. But also you're looking at porosity, is it going to absorb materials. Precast has a very low permeability and a very high strength, so usually you don't have a whole lot of that, but when you're thinking of agaric, sometimes certain agarics might be more porous and more apt to do that. You also have to look at your environmental considerations, right. What kind of environment am I in, in a city, is there a lot of smog, am I in a manufacturing environment, is there a lot of dirt blowing around, and how will that play into it long term. Overall, all of this really reinforces the importance of working with a PCI certified plant, having a really good quality assurance program in place that says everything's here and it's working properly, to give you the highest amount of probability that everything's going to turn out the way it's desired. If you're going with an agaric dominant finish, as you saw before, there are a ton of agarics out there. Most common ones you get into silica and limestones and granites and things like that, a lot of variety. It doesn't mean every agaric out there in the world is perfect for use in precast, obviously you want to avoid things that have alkali silica reactions, stuff like that. But you do have an expansive range of colors. Some of these, depending on where your project is, can be a little bit more expensive, you might have to transport, and so one thing precasters do is they might use a face mix, which is basically the more expensive aggregate or mix design is put into the face, the visible areas of the product, and then maybe a less expensive, more economical gray backup mix will be applied. It's a very common process, and again, your precaster will work with you to explain what makes sense in your project on these applications. As far as aggregates go though, color is fairly consistent with time. It changes from quarry to quarry and over time throughout an aggregate run, but I mean in terms of the aggregate, the aggregate doesn't change, whereas the paste portion of concrete can change over time. So aggregates are fairly consistent, curing doesn't affect them obviously, there's no chemical reaction taking place, well, at least we don't want any chemical reaction to take place within the aggregate. Porosity, again we talked about that, whether it's stains or not, what kind of aggregate am I using in there, and weathering, and in most cases, a lot of this is fairly durable, but it does depend on what type of aggregate you're using. Some of them, a softer aggregate for example, can be, well, worn away over time, even by just rain over time. Something else to consider is basically the shape or type of aggregate we're working with, and it really breaks down to round versus angular. The round aggregate, it's mostly river gravel, no really processing done to it. Overall they have less bonding ability because there's less surface area, they also have less dirt retention, and as we saw earlier, they're sometimes providing more uniform exposure, especially on returns and things of that nature. So that works pretty well from an aesthetic standpoint, it doesn't mean that the strength would be too low, it just means relative to some of our crushed or angular type aggregates, usually because they have more surface area, they tend to give higher strength and stuff like that. So it gets into those applications, but it can create some aesthetic issues, can be more difficult from that standpoint. So where to start? Well, we recommend, we've got a couple resources out there. First of all, if you're not familiar with the PCI Color and Texture Selection Guide, this is available in print, it's also available on our website under the Architectural Resources section. It has more than 500 mixes and finishes in there to kind of give you a starting point. Now, it's important to realize that materials vary with time, and it doesn't mean that if you take the exact mix design and make it again, it's going to end up the same, but it's a great starting point to have some conversations with a precaster and say, hey, this is something we're interested in, what could we do with this? You also want to look at your needs for the project. What is it very sensitive to panel-to-panel variation, within variation, what else is going in there, what other materials are going in there? What color glazing are we using, trim work, what's in the area, where is that project located? Am I on a campus, am I downtown, am I out in the middle of nowhere, what's the environmental concerns like that, right, is there a lot of weather, wetting and drying, is there a lot of acid rain in the area, small pollution, things like that, are we by the ocean? All of that should be discussed and play into how you end up designing for the aesthetics of that particular project. And then you want to move to samples. This is critical. You need to see real materials, touch and feel the real things, and it starts usually by a 12 inch by 12 inch or 24 inch squared samples. These are usually made in our QC labs, things like that, gives you a feel for it, you can touch it, you can see what the real materials today that are available start looking like. Then you want to move on to range samples. These are larger samples, usually in a lot of cases like four foot by four foot. An important aspect of this is to try and get these from regular production processes, and also to get them over time. You wouldn't make these all in one day. Usually you'd make them a day apart or a couple days apart or something like that. You want to take it out of the regular mixer and things like that. The more realistic you can get from production environment, the more these samples will show us what variation can be out there and get a good expectation for what a particular finish and a mix design, etc., is going to result in for us. So it's a great way to do it. Then highly recommend moving to a mock-up, either a half-scale or a full-scale mock-up. You can build these early in the project, preferably on the site quite often. It allows you to view things. You want to look at it wet and dry in different lighting and stuff like that so you can see what kind of characteristics are going to be brought out, what's going to influence those things. It can be used to assist with acceptance of materials. You can establish patching and repair procedures. For example, when you're using exposed aggregate, deep exposures, usually those repairs are pretty easy because, well, the aggregate didn't change color usually, so it's fairly easy to match in. When you have a paste-dominant finish, let's say like a form finish, those repairs can be a little more tricky because you've got a lot of variation in there, and again, those are driven by a paste, which is part of a hydration process. This can also be used to evaluate weathering, though, and other construction issues and things like that that may be out there. So there's a lot of benefit to using these kind of mock-ups. Here's an example. This just kind of shows you a mock-up relative to the project and stuff, and I'm sure you're all very familiar with them, but something that's probably well worth the investment of time and money to really get you to a, well, to get expectations correct and get to a very wonderful project. So now I want to highlight a couple of these things and look at just a few innovative projects real quick. Most of these are newer projects that really highlight what people have done on precast. The first one here, this is an office structure up in Canada. As you can see here, the use of form liners and color, really some interesting details on these panels, good integration with window systems, glazing systems, and stuff like that. Some people have, some architects said that this is, like, almost reminds them of, like, a metal look to the finish, some of the things that have been done out there like that. Then you have what we've seen already earlier, a couple pictures of the Perot Museum in Dallas Texas. It's been on the cover of many magazines. This is a form finish, an as-gassed finish project, but with tremendous detail. All of these pieces, you can see angular joints. There's a lot of turning, concave, convex shapes, radius pieces, tremendous detail on projections and the randomness of the projections. Some of these are, like, eight-inch projections. Really highlights what can be done with the material and the form work and the details and stuff like that. Now, this, this is a very large shopping mall in Mexico, actually, and what I find really interesting is when you look at it, I'm sure most people are going to say, okay, they veneered stone on there. That's not true. That's actually precast concrete. That's the exposed concrete. What they did here is they used a combination of techniques from pigmenting and acid etching and chiseling, in some cases, to replicate or emulate, if you would, this particular stone. And I found it interesting because they did it, they said, because the stone was actually a lot more expensive and difficult to get and put into place. This was a much more economical way to go, but when you look at comparisons, you really can't tell them apart, and it just shows a whole other approach in how you can utilize this versatility. This is a parking structure up in the New England area here. Again, we see a lot of gray colors and some darker charcoal colors in there with the precast. Great integration with screen systems, some metal plat systems in the back there. You'll see a lot of projections. These are two, I think, to four-inch projections coming off of this. One thing that was kind of interesting is the Hartford Hospital said this was their starting point. This is setting the tone for the new aesthetics at the hospital, and they started with the parking structure of that. We have a courthouse. Now, this is kind of more traditional veneer work here. We've got limestone veneer at the top, and we've got a granite. You can kind of see here in the bottom picture around the base, but as you can see, veneered precast concrete, a lot of detail in the work here, columns and cornice work and stuff, some beautiful details and things like that, but the entire building is clad with it. And again, much more economical, much more efficient way to get this material on the building and in the structure. This is another courthouse project. This is up in Billings, Montana. Really interesting form line of work here, a slightly acid-etched finish on it, two colors, takes on some really amazing shapes. And you talk about integration of the different systems, optimizing, but this has also been designed for blast resistance, great thermal efficiency, I think over a 30% or 35% reduction in energy costs over code, things like that, all combined together to make this project complete. And then finally, you saw this probably before, this is the Millennium Complex up in Penn State University. This is a thin brick job, stacked bonds, two different types of thin bricks, some recessed banding in here and stuff like that, incredible cantilevers both on the front and on the back of this two-sided structure because it juts off in both directions. As you can see, a very difficult project, if even probably just impossible to do with a field-laid brick, but Precast offers an excellent solution to achieving this type of aesthetic. And whether you like it or not, they've done some real interesting things here. And then finally, I'm sure most of you are familiar with this, this is of course the Jubilee Church in Rome, and I'm sure most of you have also heard this is a self-cleaning concrete. So beyond the beautiful curved shapes of Precast concrete there, this has titanium dioxide in it, which is basically a self-cleaning admixture, if you would. It's a photocatalytic catalyst, and basically it just accelerates the formation of oxidizing reagents because it's a catalyst, it's not consumed in the operation or that process basically. And it breaks down the organic and inorganic materials, so it keeps, well, white-looking white, very clean. It also helps reduce the pollutants and stuff, so it's another interesting example to look at. So anyways, some recommendations to try and keep in mind, there's a lot of material we go through today, and I can't stress enough how much to sit down and talk with experts early in the project, the Precasters can really help you get a handle on this. There's a lot here to look at and take into consideration. First, match your paste, sand, and stone. Quite often, that's going to produce a really good color uniformity, it's going to be very beneficial. Again, depending on what finish you go with, paste is going to be more dominant or stone is going to be more dominant, and you want to understand how that's going to play into it. You want to use white cement or blends of white cement, like I said, especially in paste-dominant mixes with pigments. It's going to help, white cement has color consistency in it, so it's going to help improve consistency. You want to use a slightly darker matrix with deep exposures. If you think about that, deep exposures means a lot of aggregate showing, usually a lot of time is done with the surface retarder, the exposing aggregate that way, and if you get dirt and stuff trapped in there, you want to use a darker matrix, it won't show the change with time that much, so it's something to keep in mind. There also improves, of course, any kind of, reduces variability, and rounded aggregates will help with the weathering, like we said, and also from an exposure uniformity standpoint, usually there's no problem meeting any strength requirements with that until you get into extreme strength, you start talking like 12, 14, 15,000 PSI concrete applications where you may need to go with a different type of crush aggregate. Finishes side again, composite porous, great ideas for returns greater than 12 inches. Consider how those returns are going to be viewed. Are they just a small portion of the panel, are they returning into a balcony area, are they seen on the ground levels, are people being able to walk up to them, other ways to go around corners, things like that. When you're combining finishes, which by the way is a very economical way to get different finishes or different materials onto a structure, you want to use demarcations like reveals, things like that, to separate them, and also we talked about using some sort of difference in the finishes, noticeable difference, so it's crisp and clean and really can be utilized. And I won't stress it enough, but always involve a precaster early in the process. So from a final summary, precast concrete really does offer just excellent aesthetic versatility. Endless, well, almost endless array of colors, textures, finishes, details and form work, things can be veneered, things like that. Combining finishes is a great approach, you're going to reduce time, costs, and obviously construction complexity in doing that. Can't stress enough the importance of using a PCI certified plant and quality assurance because, well, as you saw today, there's a lot of things that influence color and the finish, and quality assurance needs to be in place and operating correctly to do that. No better way than to use a PCI certified plant to accomplish it. And like I said before, give a precaster a call. Early in your project, when you're just starting to think about things, hey, can precast work for this project? You know, we were thinking of using this material, what makes sense? And they won't see you wrong, they'll share with you ideas, they'll probably share with you things you might not have thought about to help optimize the project, and not even just from aesthetics. Like I said earlier, think high performance, we're trying to optimize all the relevant attributes to the project with the aesthetics, and get it all to work out really well. So with that, I think that that is my time. Jen, are you there? Yes. Thank you, Brian. It is just about 1 o'clock now, so we'll go ahead and wrap up the webinar. As a reminder, if you are at a location with more than one attendee on the line, please complete the sign-in sheet and fax it back to PCI using the number on the form. Your certificate will be ready for download from your RCEP.net account a few weeks following the webinar. Additionally, a survey will appear as you exit the webinar. Please complete the survey. This will help us plan future courses and help make them most valuable to attendees. Our November webinar will be The New Sound of IEQ, Indoor Comfort and Acoustic Design, and will take place on the 19th and 21st. The presentation is open now. This concludes our webinar for today. Thank you, Brian, for a wonderful presentation, and thank you to everyone for attending. Have a great afternoon.

precast concrete

aesthetic versatility

finish options

embedded materials

advantages

fundamentals of concrete

high-performance structures

sustainability

thin brick veneers