Standing Strong - Transcript
On April 10, 2008, Popular Mechanics and the National Science Foundation presented "Bridges to the Future: A vision for infrastructure in the 21st century," a webcast discussion exploring the best ideas for improving American infrastructure and building a better, safer future. This is a transcript of one of the panels. For links to the other panels' transcripts or for more information about the webcast, see the Bridges Webcast Conference page.
>> Eric Sofge: I'm Eric Sofge from Popular Mechanics. And here today, we're talking about infrastructure. This is a three panel discussion that we're holding in partnership with the National Science Foundation and right now we're going to be talking about physical structure. Specifically how do we fix our dams, buildings, bridges and roadways. Now, I'm joined today with an esteemed panel. Here we have Linda Figg, President and CEO of the Figg Engineering Group. Also we have Kim Roddis who chaired the Civil and Environmental Engineering Department at George Washington University. And live via satellite we're joined by Matthew Realff who is an Associate Professor at Georgia Tech School of Chemical and Biomolecular Engineering, sorry about that one. And Yang Wang, Georgia Tech school of Civil and Environmental Engineering. Just to explain how it is going to work, I'm going to ask a round of questions to our guests here then we'll open up questions from the audience as well as callers and email. So if you are watching this webcast right now and you have any questions that you want to email or if you want to call in please do so now. That way we can queue you up and get everyone's questions answered. Also if you are going to call in please turn down your speakers at home so that we don't have any interference. Here in the audience if you can turn off your phones as well as if you are going to ask a question please make sure that you have a microphone so that we can get that recorded for everyone to hear. So to start things off, last August a bridge collapsed in Minnesota. 13 people were killed, around 100 were injured. That sparked a national debate about infrastructure in the U.S. whether it is in crisis, whether it is crumbling. Our question here today is how do we fix it and what lessons can we learn from that. And what technology we can use to try to fix this system that seems to be in trouble if not in crisis. So I would like to start off with Linda. Your firm is actually working on the bridge that is replacing the I-35 bridge. Can you tell us how the design of the new bridge might make it more stable?
>> Linda Figg: Like you're talking about this is an important time in our history. It's an opportunity for us to take advantage of the great technology that we have available in the marketplace to rebuild our infrastructure. And the I-35W we hope to be an example of that. It is a high-performance, high-strength concrete structure, and we're incorporating the latest technology that we have today such as using sensors in the structure, it's smart bridge technology. There will be about 240 sensors throughout this bridge. Basically four different types; accelerometers that talk about deflection of the bridge and chloride penetration sensors that help us to evaluate the condition of the deck over the long term, wire strain gauges that help us to know about the stresses and temperature of the concrete. And linear sensors that talk about the movement of expansion joints and bearings. All of this is really creating a great database for the future. It gives a wonderful resource of information that will help us become better designer for the long term.
>> Eric Sofge: Yang you worked with monitoring systems in different structures. Can you tell us a little about your work and the results that you have seen?
>> W.M. Kim Roddis: Yes, Eric. Our research focuses on developing wireless sensors for structure house monitoring. I need to just mention this monitoring system or the instrument on the new I-35, there are also a lot of other bridges being monitored. I'll give an example of a Long Klebow (ph) State Bridge that is being constructed in Hong Kong that's going have a thousand sensors on that bridge monitoring that bridge condition. Because it's a big bridge, it's very expensive to cable the whole bridge so these sensors cost about $1,000 each so the cost of whole system is about a million dollars monitoring system. So we try to develop wireless sensors where you can get rid of all those cables and save time for installing the cables and you just have the sensors on the structure and they can measure the condition structure, you can do some simple analysis to the data and try to determine whether the structure is safe or not.
>> Eric Sofge: Matthew, if we are able to actually get the funding to build and reconstruct all these new structures that need to be fixed, can you tell us how we might be able to limit the environmental impact of all those new projects?
>> Matthew Realff: The issue here is how to most effectively recycle the materials out of the existing structures. So today we have developed very effective recovery systems for the metals and concrete and other such large mass components of many of the buildings and bridges. But there's also a lot of other things that are now inside of billings like ceiling tiles, carpets, molding around the sides of the buildings and we need to be able to figure out how to recover those materials most effectively as well so we can avoid the material crisis that we seem to be facing with respect to the competition for things like cement and iron ore and steel that is being forced upon us by other countries needing to develop their own infrastructures at the same time we're attempting to replace ours.
>> Eric Sofge: And if we can increase the life span of these new structures going up, will that also I guess help when it comes to this issue of needing to recycle and the cost of that process?
>> Matthew Realff: Yes. I think that again if we're able to extend the life of these buildings and to replace the components as they fail rather than attempting to replace the entire structure based on no real knowledge of exactly when it's going to end its life, that will help improve the material efficiency of our infrastructures which overall do consume a significant fraction of the raw material and resources that are brought into the U.S. and mined out of U.S. infrastructures to be able to improve our overall efficiency as a society.
>> Eric Sofge: It seems pretty obvious what sort of benefits we'll have by extending the life span of again all these new structures and or even ones we're reconstructing but I guess the question is how. Kim can you address how we can do that in a cost effective way?
>> W.M. Kim Roddis: Well I think what it is is if we think about when people are doing the design, whether you're doing the design initially for a new project or you're doing design for a renovation or replacement on a project and you think about what information people have available to them to be able to do that design and one of the things that we have for technology advancements that we are putting in place now but that we need to continue to make better tools to be able to do this is how do we get the right information to the right people at the right time? This is an advanced computing problem. It's an information management problem. So when you think what we're doing with computational tools how do we wind up using our advances and computing power to better model not only the structures that we're trying to build and maintain but also the processes that we use to do that. So the kind of information for example about trying to design a bridge that would last longer that Linda was talking about, well on shorter span bridges often we can eliminate the joints in the bridges, those are a part of a bridge that wear out very quickly. So when somebody is designing the bridge they need that information about that, it's a critical thing for your design objectives is to have a jointless structure and then how to get that executed. When we're trying to replace a bridge or building on the other hand, we want to have a model of that building so what Matthew was talking about, he would know the person that he or she--the team of people that was trying to get this done would know what kind of contaminants might be in there. What are the different products? How could they be recycled? So that idea about having building information models which are really coming into their own right now but we're just sort of starting on that. So in 2025 we're going to be designing our--and maintaining our structures quite differently. And it's not just advances in the materials and the structural systems that we're working with but also the information and the computational side of things. They tie together.
>> Eric Sofge: Linda, you design bridges basically for a living. I think that's a good question. What do you think the bridge of 2028 will look like?
>> Linda Figg: Well, it will be an extension of what is going on right now but we'll be looking at more improved materials. We're being able to get better technology with materials, higher strength concretes, higher strength steels, fiber reinforced polymers. We'll be able to have more corrosion resistance in our materials which will give us structures that will last longer than in the past. We're looking at well beyond 150 years with the technologies out there now. This is great because the investment in our infrastructure is a high dollar item. And we need our infrastructure to last longer. That's all good for sustainability and responsible construction. We need longer-living structures.
>> Eric Sofge: Matthew, I guess we're also wondering what the potential environmental impact is of these new materials that we're talking about, the sort of flexible concrete, self-healing concrete, all these sort of gee whiz materials will this have a sort of serious environmental impact compared to what we have got right now?
>> Matthew Realff: So the environmental impacts will be different, I think that's the issue is that we have used a lot of the materials today, irons and steels and concretes for many years and we have a reasonable understanding of what their impact is. But as we incorporate other materials such as nanofibers or nanotubes and other materials into--into those, we're going to experience a new set of environmental impacts. But again, that's not to say that those--that that is necessarily good or necessarily bad. The issue is to be able to derive the information now to understand those impacts before we spread them widely throughout our society. So if we take the example of asbestos as a construction material, it was not very well understood when that material was used, what its impacts might be longer term. But now that we have been through that experience it's possible for us to do the testing necessary to make sure these materials are safe before we deploy them in wide-scale use.
>> Eric Sofge: And Yang, what role do you think sensors will or not play in these new materials? Is it actually easier to install them or is it going to make it more difficult?
>> W.M. Kim Roddis: I think those sensors will help you to use those materials more efficiently. The sensors will (inaudible)--we hope each single sensor the price may be $5 to $10 in about 20 or 30 years. This help us to have a very good feel how the structure really acts in real life. We can have constant monitoring so with this accurate prediction to this structure behavior we can have a more efficient usage of those new materials when we design a new structure and use it more efficiently.
>> Matthew Realff: I think--if I might leverage from that another type of sensor we can use is RFID, radio frequency identification tags. For example, those are very, very cheap sensors coming down now into the few cents range. It will be possible for us to actually place those sensors on individual structures and members within the structure and then just go through the structure and actually inventory all the material that was actually in the structure with those type of sensors. So again, that gives us the opportunity to have a much better picture of what materials are there and how they have been used and what exactly might be the way to recycle them in the future, to come back to a point that was made earlier. This whole idea of substituting information for materials that is extremely important and can really lead to orders of magnitude in improvements in the efficiency of our infrastructures as deployed today.
>> Eric Sofge: Kim, you have actually inspected bridges yourself.
>> W.M. Kim Roddis: Yes.
>> Eric Sofge: I guess what I'm wondering what impact do you think the sensors or any new technology that's going on in terms of devices that can see into concrete to find cracks and devices like that. What sort of impact do you think that would have on inspection?
>> W.M. Kim Roddis: I think this is really one that's--from a--from my point of view you have to remember that there's really very different kinds of classes in what makes up our infrastructure. And so when people think of bridges they usually think of a major crossing, a signature span kind of bridge. And most of the infrastructure that we have is a lot more mundane. It's still very useful and we go over them all the time but most bridges that we cross are going to be 100 feet or less. So they'll be more like a typical overpass that we go under all the time on a highway. So for those one of the things that I think is going to happen is that the kinds of sensors that have been mentioned, Linda in particular mentioned the chloride sensors. What are some of the things that really make those bridges fall apart right now. One of the problems we had is the life of the deck. The life of the driving surface, which typically is going to be concrete with reinforced steel in it. The steel maybe epoxy coated but what we need to be doing is moving from those concrete decks that under heavy loading have life spans of less than 20 years to something where we have a 40 or 80 year bridge deck. To do that, partly it's improving the materials and moving to things like composite bridge decks which many researches are working on that would live longer but it's also what Dr. Yang and what Linda has talked about here about being able to know what's going on in the structure now, so that people that are planning how to maintain our roads can know it's like going out and taking somebody's temperature to see whether or not they're coming down with the flu, and may be able to do that for the decks on hundreds to thousands of bridges that were on the routes so they can do better planning. Does that address your question?
>> Eric Sofge: That makes sense.
>> Linda Figg: And with these bridge decks, traditionally it's been a reinforced concrete deck. Yet we have technology today where we can use transfers and longitudinal post tensioning to really gain extra strength in our concrete and compression so that we can minimize that salt intrusion or the chlorides and give our decks a lot longer life.
>> Eric Sofge: Popular Mechanics has been reporting on and other magazines as well on these sorts of revolutionary materials for years now. I guess what I'm wondering is how long will it take to get them out of lab or what will it take to get these out of the lab and into bridges? Especially the rural bridges, the smaller bridges, that might not have as much traffic as I-35 West did? I guess either one of you.
>> Linda Figg: I think one way is to have these materials work in concert with other materials that we're very familiar with. One of the big components of bridges today is we must have redundancy. So having more redundancy by testing these new materials in with a system that's already designed to be self-sufficient with materials we know already, helps us to be able to study those. For instance there's a cable stay bridge in Maine where we put in the cables the cables themselves have a few extra strands in the cables that we aren't really using for capacity. But instead of using steel we replaced those extra strands with fiber reinforced polymer. So we have a real test case where we have this new material in operation in a bridge. Now we can look over the long term to see how this operates. Yet we're not really using it for strength but we are using it to be able to see how this will work so then maybe the next time we can use a little more of it. This will help get it into our marketplace much faster.
>> Eric Sofge: At this point if there are any questions from the audience I think we're ready to take one. I think we need a mic.
>> Male Speaker: Hi. Jim Mags (ph) from Popular Mechanics. That question about moving new technologies outs of the lab or out of certain test applications as Eric says we have written about many times over the years and get them into common use requires that the customer for the infrastructure, typically the state or in some cases federal client is interested in that kind of long term thinking and the value of a roadway deck that's going to last 40 or 50 years instead of 20 years. Are there enough incentives in the way that our infrastructure bureaucracy is set up to encourage that kind of long term thinking?
>> Female Speaker: : May I make a comment on this? One thing I'm involved in somewhat, there's something that's called the Steel Bridge Collaboration that is made up of the states and the fabricators for steel bridges. So this is a case where the people that really care about having bridges work and really making the technology move into the marketplace are actually working together in a partnership so that instead of having an adversarial relationship that you might expect between the owners and suppliers, or the people that are bidding on it, instead what they're trying to do is get together and say how do we all make the specifications better? How do we all change the business model that we're doing on the bids so that we can bid to a computational model for the bridge instead of bidding to paper set which is just a small subset of the information for the bridge. So that's one answer is that the system itself is quite interdependent and is very responsive. Unfortunately, this doesn't happen as much with buildings because buildings have so many different owners. So here you have something that's on the public side and you might think it's having less incentives because it's not as open to a pure free market, the building is, and it's actually been when you really look in detail over the last ten years about where the innovations are getting in, they're getting in more on the bridge side. And it's partly because you can have a modified free market which is basically what we have for our public works system. So I think that's a very interesting thing. And the other thing is that the Federal Highway Administration, so when reallocate the money through tax processes, the Federal Highway Administration does exactly what Linda was talking about, specifically having technology transfer. The National Science Foundation does that. So the researchers that are involved in that, I believe Matthew and Yang both work with people that are really out in the field doing this. It's not like the academic researchers are divorced from the field. We go and work with these people. The other--so that's the positive side. The negative side is that we as a culture are only investing about two-thirds as much in our infrastructure and have been since about 1980 as what we were doing before that. And I think that that is a decision that we have to make as a culture. So that's a different question.
>> Eric Sofge: Yang, we have talked about this in the past how the U.S. sort of rates against China and other countries in terms of this willingness to spend on infrastructure and on sort of things like sensors and other monitoring systems. How do you think we stack up right now?
>> Yang Wang: I think from what I have seen so far, a lot of the--recently most highly instrumented structures they are coming out in East Asia, not the United States. I think one of the reasons maybe owners the bridge owners or building owners in the United States are more cautious about their spending. We have to say, you know, this new technology is good, it looks good but it costs money as well. How do I know that in the end this first cost money can save me money in the end? Because we have to do a life cycle cost benefit analysis to the structure either using the new material or using a new monitoring system in order to ensure that the owner actually is willing to pay this up-front.
>> Matthew Realff: I think the point there is that the information model that was brought up earlier is a very important factor in being able to demonstrate the life cycle cost. You don't have the bridge there 30 years and say oh, I need cost X. You have to be able to predict the cost over the life cycle, which requires that prediction requires that you have the computational model to be able to say yes, if you make this investment this will be the savings you will see 5, 10, 15, 20 years down the line. Again, in the public sphere where we do actually have the capability of looking out that length of time without necessarily responding to immediate shareholder value requirements there is the hope you can do that in those type of infrastructures.
>> Eric Sofge: Actually, we have a question from--an email question from Isaac Cronan (ph) from Berkeley, California. Isaac is asking what kinds of next generation materials are being developed to help bridges withstand impacts from earthquakes to explosions? I think one of you may be qualified to answer this one.
>> W.M. Kim Roddis: There's composite materials out now that are used to wrap concrete which help give additional strength and also work within the issues of seismic and flexibility needs that are there. There is all kinds of materials now that we have that give us greater strength in concrete so that impact force is actually can be something we can take within our design and even be streamlined in our design, not as massive as what we might have seen in concrete elements in the past. And we have technologies in labs such as in wind tunnels where we can analyze the true characteristics of shapes and be real refined in the shaping of structures so they can withstand major hurricane events and still be serviceable afterwards. So that is very helpful, we can look at that from a lab basis.
>> Eric Sofge: Actually in the course of this investigation for the article we wrote in Popular Mechanics about infrastructure in the U.S. this issue of earthquakes came up a few times. Particularly in relation to dams where it's been largely ignored at least that's what a lot of researchers we spoke to, that's how they felt, compared to other structures and other risks, flood, or related sort of problems with dams. I guess if any of you can speak to that issue of I guess where we are in terms of earthquake resistance when it comes to dams and other sort of water related structures. Although--
>> Matthew Realff: That's not unfortunately our area. One thing we taught here, was again thinking about materials is one way of going about making these structures stronger. Another one is the dynamic response, building that in. In other words attempting to have the building itself be able to adjust as the shock hits it. That's another way of approaching this type of problem.
>> Yang Wang: This is a new technology called structural control technology we but activators in the structure so when earthquakes or typhoons happens those activators can in real-time generate forces to counterbalance the excitation to try reduce the structure vibration in real-time. This actually helps to protect the structure.
>> Eric Sofge: Is that actually being installed right now or is that more in development?
>> Yang Wang: Actually for most of the technologies there's a lot of real life applications of composite structural control where we have dampers (ph) if you look up City Hall at San Francisco there's a lot of this composite dampers instrument in that City Hall.
>> Eric Sofge: Okay. One thing that I would like to address, it's kind of the elephant in the room is the issue of money and how we're going to pay for everything we're talking about from bridges to dams to levees and all this physical infrastructure that's not managed necessarily by private companies. I guess I'm wondering how you think we can get the public interested enough or politicians, anyone interested enough to actually pay the money we think we need. And so I guess I'm actually interested, Matthew, because I fell like a lot of your work involves cost cutting and especially with recycling. I guess are you willing to tackle that question?
>> Matthew Realff: So I think that the answer is that it's been demonstrated time and again that the public responds when some catastrophic event happens. They see the impact of having a bridge fail and these are the opportunities then for politicians to use that public good will to move us forward in terms of making these investments. I think the other thing is that again, using models to demonstrate to all stakeholders whether it be politicians, whether it be the general public that building a more--a smarter structure or building a stronger structure can over the long term save the public money is a way to go about this. I think it's a failure sometimes of communication rather than anything else that we haven't communicated the case for these kinds of investments well enough rather than it being the people aren't willing to make the investment once they see that there is indeed a return on it.
>> Eric Sofge: Linda, I was going to say.
>> Linda Figg: You know, the need is overwhelming. I mean, there's--when you look at bridges you have both the functionally obsolete which means they aren't wide enough, they don't have proper shoulders, they can't carry the amount of traffic that's really needed to push through that corridor. Then you have the functionally--the deficient structures which are just the wear and tear of the bridge, needs to be replaced because the materials are failing. And when you combine those two, it's an overwhelming amount of money that's needed to repair and replace our infrastructure. So it's not going to be one source that's going to be the ticket for one size fits all. It's going to be multiple sources. We're going to need state and federal money, we need to look at tolls. We have to look at how can our local resources or even developers help with some of this. It's really multiple scenarios. And for instance, one example would be how we take a corridor that is just packed with traffic and try to expand it within the right away and maintain environmental sensitivity. Perhaps there's a way like where we can build up through using a median to build a structure. We did this down in Tampa where we had a six-foot wide peer but on top of it is a three-lane structure that is reversible. So in the morning if you live in the suburbs you take in ten minutes you get down to the city in these three lanes going in town. In the afternoon it reverses and you go three lanes back out. And you pay a toll for that opportunity, $1.50. But you're out of the traffic, you're non-stop and it doubles the capacity in the existing right away in only six feet of space. So there are ways in which we can really manage our traffic and offer free and tolls and get the job done in kind of a multi-facetted approach.
>> Eric Sofge: Public transportation is also incorporated into that project.
>> Linda Figg: It is. It doubled the bus system which wasn't--it was only functioning slightly. But now what happens is people park at an outside mall, get on the bus, and it doubled the buses going back and forth because it was reliable. Now you have guaranteed delivery at a particular time.
>> Matthew Realff: I think this speaks to a broader issue, which is we need to think about this as providing transportation services and not necessarily providing roads and bridges. Really what people demand is a reliable transportation service and not demanding acres of pavement. That's not the actual need. So if you can develop reliable transportation services, public transportation services combined with private services and create the incentives through tolls and other payment schemes, you can really develop a very different looking service as opposed to a road.
>> Eric Sofge: Actually we have an email question that is addressing this issue indirectly of congestion. Steven Walker (ph) from here in Arlington is asking are there new technologies that will replace or improve Easy Pass and make it available to more people which would in turn contribute to the elimination of traffic bottlenecks? It's pretty specific question. Does anyone have any insight into that one?
>> W.M. Kim Roddis: One of my colleagues at George Washington, Azi Maskadarian (ph) does quite a bit of work in intelligent transportation systems so that's one of our main labs in our department. And yes, there are indeed technologies that would do that and not only would they--again, it's an issue about what transportation services do we want to be delivering. Because one of the things they are doing is not only looking at this thing about making the Easy Pass more available but the people to reduce the congestion as you're going through the particular tolls. But looking at applying what London has done, which is applying pricing so you have tolls based on the congestion. So what happens is you pay a toll for riding on the normal surface roads, not the toll roads. And that is priced according to the time you're driving around London. That has been very effective at reducing congestion. That is something that is specifically discussed in Arlington in the northern Virginia area which is one of the ten most congested areas in the country. Since I have the floor for a minute, Eric asked the earlier question and Linda talked about structurally deficient versus functionally obsolete bridges. Remember that we do have a huge amount of our country that is semi rural and rural. So one of the things that I was able to do for research which was enormously satisfying is the Department of Transportation in Kansas funded me with two different doctoral students to work on how do you take bridges that are on rural routes, so they don't carry very many trucks per day, but they're very important because if you take one of those bridges out they can easily add 50-miles for what you have to do for the detour. So they're very costly from a market delivery to market point of view. So what we can do is when that bridge needs to be redecked which is usually the first thing that happens, if the problem with it is out of plane distortion cracking on the girders which is 80% of all cracking problems in the United States on our highway bridges are due to that one cause. And if that's the cause then it's not functionally obsolete. We can go in and we can redeck it and we can fix those girders when they're doing the redecking for 3% to a maximum of 10% of what it would cost to put in a new bridge. So that would mean you could put in 33 of these fixes instead of putting in one new bridge. That's part of the thing about trying to have our system providing the traffic services very much what Matthew was getting to, about you don't have a one size fits all solution.
>> Eric Sofge: Actually, Matthew, you mentioned that the impact of a bridge collapse can have on people's awareness of infrastructure. When it comes to buildings for example or anything that isn't a bridge that doesn't collapse in that dramatic a fashion, what do you think can be done to sort of raise public awareness?
>> Matthew Realff: Well I think you have seen a tremendous growth for example in certification of buildings from an environmental performance perspective. So there's this green building certification system called LEAD (ph) which has been adopted quite widely throughout the U.S., a number of state and federal agencies require their buildings to be certified in this way so that has created an incentive now and they demonstrated these buildings can actually be cost effective so they tied environmental performance and a simple grading system of bronze, silver, gold and platinum levels to the overall performance of the building. So I think we're seeing a spread of these kinds of green standards to other products. For example, I have recently been involved in the development of a similar standard for carpet. So there is in fact now a standard available for carpet so you can get silver, gold or platinum certified carpet that has again an overall environmental profile that is lower than other types of carpeting in the commercial buildings. You can help--that can be used in buildings to gain new points towards the LEAD system so you can have the LEAD certification more effective. So as we start to develop these standards so we can actually see an increase in the use of sustainable products and sustainable standards to help improve the overall efficiency both in terms of material and energy in these environments. I think that is now much more awareness in the public sphere of these kinds of standards.
>> Eric Sofge: And Yang, do you think there's a way to sort of leverage what happened in Minneapolis to sort of help people understand the impact or the sort of benefit of monitoring systems? Particularly bridges but I guess in any structure that could conceivably collapse.
>> Yang Wang: Yes I think a lot of Departments of Transportation are now paying a lot of attention to their bridges. For the buildings particularly the buildings either in earthquake zones or typhoon zones, those high rise buildings, a lot of them are being instrumented with censoring systems for monitoring their behavior. The 1989 (inaudible) earthquake in the Bay Area, there were buildings in San Francisco that were instrumented with sensors but now it's--with the price of those sensors getting lower and lower we're expecting to be able to instrument more building structures in the future.
>> Eric Sofge: All right. We actually have another question emailed to us from Jimmy Camp (ph), from New Mexico. The question is, the budgets for bridges have been relatively flat in the U.S. for several years. However, costs have been rising fairly rapidly. Are there any low cost initial solutions on the horizon? That's another hard one. Well, I guess it's also about money. That's always a harder thing deal with. But I guess if anyone is willing to try.
>> Linda Figg: I think that where we can gain our greatest economy in bridges is in these new materials. And in the strength that we can gain from them. So for the high-strength concretes and high-performance materials, it helps to drive a lower cost. For instance, there is a concrete called self- consolidating concrete. Basically what you do is it pours like a liquid. This reduces the amount of labor that it takes to actually pour and put the concrete in place. Labor is one of the biggest cost factors in the development of new bridge. So when you can help streamline the efficiency of construction that's really where we can do the most in terms of benefit of cost of our structures. Plus we're going to be faced with a labor shortage in construction as we move forward in this country so we need to look for more efficient ways of being able to construct.
>> Eric Sofge: Actually can you talk more about that issue because I wasn't aware of that problem that we're going to face a shortage in labor.
>> Linda Figg: There aren't as many people going into the construction arena. So in the future we really have to do more to recruit both in engineering and in construction. There are predicted pretty major shortages coming up in the future. So anything we can do to inspire young people to go into these professions would be outstanding.
>> Eric Sofge: Actually recently I was at MIT looking at a proposal for an automated system that would essentially weave a structure out of composite materials, almost like sort of almost like using yarn to basically create a tube. I'm wondering what sort of impact do you think automated sort of construction could have on this industry. Obviously I thought that there would be an issue of maybe stealing jobs from humans but I guess if that's not an issue, sounds like it could have real benefits.
>> Linda Figg: Whenever you can prefabricate elements in a controlled environment, not only do you get speed but you get economy because there's a repetition of a development of those elements. Similar to the process we're using on the I-35W bridge because the main span is made out of precast box girder segments that are pre-fabricated on the roadway on the south side of I-35W roadway. We're pre-fabricating them in these shed areas. Then these segments will be trucked down and it will be like big legos being put in place and you gradually add these next to each other until they meet in the center of the 504-foot main span. This can then be done in terms of assembling these segments in about eight weeks or something like that. You all of a sudden have a 504-foot main span. But it's in a controlled environment so you really have a lot of great quality control, it's ease of fabrication, it's easier to do that over land than it is over water. So you really streamline the process that way.
>> Eric Sofge: I want to take a minute to check with our operator just to see if we have any callers waiting to join the discussion. Sara.
>> Operator: I have no audio questions sir.
>> Eric Sofge: Okay. I also would like to check in with the audience. I think we have got a question.
>> Audience: My name is Richard Spivak (ph). I'm with the National Institute of Standards Technology. My question is public infrastructure--infrastructure by definition is public. Do you see now or in the last several years a commitment by the feds or state locals to spend money that's necessary, and if you do where is it coming from? Is it fed driven, state driven, local driven?
>> Female Speaker: : I don't think infrastructure the way we deal with infrastructure in the United States that it's inherently public. There are things that I think for example the medical infrastructure depends on hospitals, a lot of hospitals are private, not public so I think we have a much richer economic model and a lot more options than that. But we do have a real problem and I think people keep referring to that. That it's very clear in the last 30 years that we have not as a society been putting the money into the public part of our infrastructure that is necessary to maintain and extend that infrastructure. And the American Society of Civil Engineers, we get back to communication issues. And Matthew talked about the LEAD system. The American Society of Civil Engineers has the report card on the infrastructure for the United States and it goes through and looks at 18 different categories I believe and it looks at bridges and airports which we haven't been talking about or another thing, schools. And it's pretty clear. And it's pretty clear that people agree on kind of a ballpark, that we're spending about two-thirds of what we need to be spending on that. I mean, some people may say quarter, some people may say we're spending half with the variation. (off mic comment) It's really a combination. Our U.S. highway system predominantly gets funded through federal funds. But there's usually a match with the state. We also have some state and then of course local is always interesting dilemma because our funding is stretched so thin amongst so many needs that are out there. But it's a very important question for today. It's one that has to be answered because from the year 2003 to 2006 our cost for infrastructure grew by more than 40%. So that is just in basically the bridge that you went out to build in 2000 now costs 40% more than it did then. So now not only are the needs still great but you don't have--your money doesn't go as far as it used to. So we have to find now a way to use that money more wisely so that we can have a longer living infrastructure and not have to be replacing as often.
>> Eric Sofge: Actually I think we have another question from the audience.
>> Audience: This is Kim Chong (ph) from the National Science Foundation. I like to revisit the question that you raised about earthquake engineering. I think one of the main reason for the damages in any earthquake is because of the mass of the weight of the bridges. So the lighter you make the bridge, the easier it is to withstand the earthquake. So about ten years ago I proposed some kind of intelligent bridge to the USA Today. They did an interview with me. Some of you might have seen that, it was a full page type of intelligent bridge that appear. So some of the features I would like to mention to you and I would like to chat with Yang and others to find out what is the state of the art of that, if that's okay with you.
>> Eric Sofge: Yeah, I think so.
>> Audience: This futuristic bridge is consisting of really advanced composite materials. It could be nanocomposites. It maybe ten times lighter than the conventional bridge. So the moment of inertia is much lighter. So in an earthquake type of situation you wouldn't have that kind of damage. But in a wind situation your car would be galloping. So you need a lot of sensors, you need a lot of feedback control and actuating and the close lip (ph) system for this active or passive control as Yang has mentioned. This is one of the features that I propose. Another feature was some of the optical fibers could be used as sensors, which could also be part of the structure itself. So it's a continuous sensor. It also have self-healing type of materials. It has smart paint, it has geothermal energy that you can pipe from the river bed to de-ice the deck so those bridges in the northern hemisphere or colder temperatures is a very green technology. So those are some of the features that I propose. That was about 11 years ago. So I would like to find out from you what is the state of the art of some of these features, whether anybody has done any work in those areas.
>> Eric Sofge: Yang, I think he was wondering particularly what you think about that proposal.
>> Yang Wang: Hello Dr. Chong. I met Dr. Chong before I started. There's been a lot of research going on in nanotechnologies, I think Dr. Chong is one of the experts in this area. I am not working in that area but I think there may--we still need more time for the researchers to be able to bring those technologies into practice like the smart paint--that Dr. Chong has mentioned. When we were talking about sensing before we are using sensors these are discreet sensors, you can only put them on individual points on the structure. But individually if we have these smart think sensors, there are researchers in the University of Michigan, also University of Maryland working in this area. You can paint those all over your structure and this paint is acting like a sensor if there is crack happening on the structure surface, it can capture it right on so you don't need to worry about the sensor I put this here, maybe missing the correct position. I think there's a lot of opportunities, a lot of work being done in those areas but we are hoping to see--to see them being applied in realistic structures in the future.
>> Eric Sofge: Thank you, Yang. So I have got a question from Kaye Switzer (ph) from New York. She say what are the difficulties in managing infrastructure when it's under the jurisdiction of more than one entity or in some cases owned by private citizens.
>> Female Speaker: : I think this gets back to the question that was asked earlier, and I think on our roadway system we just restrict it to that, to the national highway system, I think that the leadership on that normally comes from the federal level because that's where the gasoline tax is set. And one of the problems that we have is the gasoline tax has been at the same level since 1993. And that--it's a level on cents per gallon so it's not a percentage level so the cost of gas as it rises it's still the same number of cents that comes out of every gallon. I think there's been a real failure at that level that with the systems not working because--so I think that that's where it goes. So then you get to this question about how do people wind up working together with it? And I think that gets back to a systems approach. But what you need to do is you need to have the different stakeholders in that situation make explicit what it is that they're trying to accomplish. For example, one of the earlier ones, is there any technology out there that would be a quick inexpensive for our highways? Yeah. Get the trucks off of them. Right. The bridges can carry most of the bridges that we have on the interstate system and the national highway system right now could have well over 100 year lives, several hundred year lives if it was just passenger vehicles on them and not trucks. So that's exactly the kind of system question that Matthew was talking about, about really what are we trying to get? Are we trying to get goods to market? In which case why aren't we using more barge traffic and more rail traffic instead of using truck traffic? So the thing is that you have to get the stakeholders together and make a decision. It's much easier when you have a physical piece of infrastructure. For example, the new bridge across the Potomac, here which is partly in Virginia partly in the District of Columbia and partly in Maryland. When there's an accident on the new Wilson bridge they have to be sure who they call and how they coordinate it because you may need Washington, D.C., people in the middle of it because they own the middle of the bridge for the emergency services. So I think that is an example where the Federal Highway Administration was able to pull together and do a very good signature project that went across multiple areas. We have this big problem, you know. From the technology side we can try and solve the problem right. But you have to look at engineering in a broader societal context if you want to say are we solving the right problem.
>> Female Speaker: : If we look 50 years ago at our design codes, we had a particular code we were designing to. Now we look 50 years out and during that time we really expected our structures to last about 50 years and we were going to be replacing them at that time. Also our truckloads have gone up by like 25%. So maybe forward thinking we look at how can we design facilities that allow us to add additional strength and capacity in the future without having to completely replace them. And also consider how can we go ahead and design now for mass transit or light rail or other types of trains on the structures so that 100 years from now we can handle those loads. We can go ahead and accommodate that on our existing infrastructure. So those are the kinds of thought processes that we see going on in the infrastructure design so that we can look more broadly at the future.
>> Eric Sofge: We actually have email from Jay Bustle (ph). His question is do you see composites becoming more main stream in bridge construction whether they're all composite decks or rebar used in concrete decks? I guess basically are we going to see more composites? I think we have a picture of a composite deck in construction. But does anyone want to field that one?
>> Female Speaker: : I think there will be some aspects of this, we certainly need more information today. There's all different kinds of composites out there and there's a lot of research that's being done, both by the Federal Highway Administration and other technologies. So it is something I think we have to look at. We have to look at new material especially when we're looking for things that can be corrosion resistant and that can give us a longer life. These new materials have different properties so we have to be able to address those whether it's fire resistance or their adaptability (ph) and how they handle UV light and all of these things can be addressed, we just have to make sure we study them properly and put them in the right application.
>> Eric Sofge: Do you think in terms of what you're doing in Minneapolis how much of an impact do you think you can have on the entire industry? I know this sounds like I'm leading you into some epic territory but it seemed to us when we visited the site there, especially that the pace of construction and the sort of attention that it was getting from tourists every weekend, there was at least I think a hundred people we were told who were stopping by, what sort of impact do you think you could have on this entire sort of movement of fixing our stuff at better, faster, maybe cheaper in some cases?
>> Female Speaker: : One thing that came to light with this bridge being out of service was how important bridges are to our local economy and our quality of life. I mean, it represents anywhere from $400,000 to a million dollars a day in lost economy because that link is out. It's a major interstate corridor. So this is so vital that it be done very quickly. By being able to combine design and construction in the same interface team and to be able to construct multiple components of the project at the same time, we're able to fast track this. So in the first six months the design was complete, 50% of all the concrete has been poured. We do have a balcony view of the project because it's right next to and parallel to the 10th Avenue bridge which has a sidewalk. Every Saturday there's a sidewalk tour. And like on this past Saturday there were 200 people from the community who came out and met with the project manager and the contractor who is accomplishing this work and he gave them a tour of the project from that balcony view. Certainly through our web cam that's 24/7 and there's two web cams and you can zoom in on the construction with one of them, all eyes are on us. And so everything that we do is to look at how we can do it better and how we can improve what we're doing. And so we hope this will be something very positive for America as we look for our--improving our infrastructure in the future.
>> Eric Sofge: Okay. Well, we actually have a few more questions from--that have been emailed in but unfortunately we have only got a few minutes so I want to make sure everyone gets the last licks in here. Matthew, is there anything else you think you'd like to address before we close this thing up?
>> Matthew Realff: I actually wanted to return to a point that was made earlier by Linda which was this whole question of thinking of construction more as manufacturing and less as a one-off kind of project. I think that's a very important point as we move forward both in terms of speeding up the construction and also being able to make many of these structures, as pointed out there are hundreds of bridges but we always tend to think of the signature projects that are done. We need to think of this as we have hundreds of bridges of very similar type and if we could develop manufacturing processes around those bridges that would standardize and modularize those we could very much improve the effectiveness of construction and reduce cost both through the application of advanced materials but also again through the application of advanced manufacturing techniques. I think it's very important that we bring those two things together and think about how we can design those together as a system. The other point I wanted to make is we talked a lot about the issue of services. And I think again we have to start to move away from thinking about constructing specific bridges and specific roadways and think about how we're providing services and how we create the right incentives for the different stakeholders to come together in a positive non-antagonistic way to deliver services to the public and the public provide the funding for those services rather than providing the funding for specific roads, bridges and other such pieces of infrastructure.
>> Eric Sofge: Yang, closing comments?
>> Yang Wang: I would like to take this chance to ask for more support from the society into our research. We have seen a lot of the (indiscernible) of bridges but we have not seen that many published in buildings. One reason is that for building owners if you would like to use them for building they worry their rent may go down. When people see this building being instrumented people may wonder is there something wrong with this building. So this sort of non- technical barriers exist to put other technologies to make them more useful for the public.
>> Eric Sofge: Kim.
>> W.M. Kim Roddis: Well, I want to reinforce what Matthew said about we're doing this paradigm shift and that we need to be looking at civil and construction, the big difference between construction and manufacturing. And instead of looking at construction which inherently is a one-off, that we look at it more as a manufacturing process. And the building information models and getting back to looking at the overall system that you're designing and I just wanted to put an example in here on buildings. There was a new automobile manufacturing plant that was built in the Midwest a few years ago. About three years ago this was done. And it used building information models and the old adage is when you want something for an engineering project you can either have it inexpensive, so the cheap--you can have it--so you can have it be on or under budget which is the cheap one. You can have it be on or under schedule, which is the fast one, or you can have it be quality. So that you can have it be high quality. And the joke is, which two of the three do you want? (laughter) Because you can only get two out of three. What this really proved is that not only if you move to a smarter way of working instead of just working harder, that we really need to be working smarter with what we are doing is that they said not only can you get something that came in under budget, ahead of schedule, it was very high quality, and the site was safer. Because what it did was it cut down on waste materials and specifically just having the building information model cut three dumpsters that they had to have on site that were emptied daily, three dumpsters were eliminated. Because they eliminated that much scrap metal in one day. So the thing is that we have an enormous can do ability to do good engineering and I think that as a society we all want to work together and be well informed. I think better decision support, more research, getting it into delivery. So this is a whole approach and I think that NSF is really championing that, Popular Mechanics is really addressing an informed part of the public about how to make this happen for the future.
>> Linda Figg: It's outstanding that we have an opportunity to have this open discussion and talk about technology. I think all of us here feel thankful to Popular Mechanics and the National Science Foundation for opening this dialogue. It is through this awareness of technology that we're able to further implement it into our projects and make it progressive and give us an opportunity to really advance American infrastructure. So I want to thank you all forgiving us that opportunity to have this discussion.
>> Eric Sofge: I guess I'll have to thank you right back. I want to thank the whole panel as well as Professor Nanni, he couldn't be here but he did provide his images of the composite sort of construction. For more information you can go to nsf.gov/bridges. Actually, if you're already there if you're watching the webcast or to popularmechanics.com. Thanks a lot.
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