Pavement Sustainability Basics

Pavement Sustainability Basics


good afternoon and welcome to the webinar. my name is Kurt Smith with Applied pavement technology and I’ll be serving as your host for today’s webinar on pavement sustainability basics which will be presented by Meesa Otani with the federal highway administration. this is part of a series of webinars on sustainability that were developed under FHWA sustainable pavements program and covers all stages of the pavement life cycle. before we get started I want to mention just a few housekeeping items of interest to everyone. we have an hour targeted for our webinar today. the presentation will last 40 minutes and then we have a 20 minute time slot scheduled to accommodate questions. the questions then will be answered at the end of the formal presentation, but you may submit your questions at any time during the presentation using the question box on your control panel. if you don’t see the question box you may need to click on the orange arrow icon on the webinar control panel to display the settings. we will work to answer as many of the questions as we can within the time allotted, but for those questions that we do not get to, the panelists will provide responses to all attendees after the webinar via email. a copy of the presentation in Adobe PDF format is available on the handout box of your control panel and the recording of the webinar will be shared with attendees once it is processed. with that I would now like to introduce monica Jurado with FHWA who provide a quick look at the FHWA sustainable pavements program. good morning and good afternoon to some of you. again my name is Monika Jurado, and I’m the pavement and materials engineer for the federal highway Resource Center. I would like to introduce the sustainable payments program manager Heather Dylla who is with us today; and on our behalf we would like to thank you for joining us for the sustainable pavement systems: a webinar series. our first webinar the pavement sustainability basics is a first of a series of ten webinars, you will receive one professional development hour per webinar, and on upon the completion of eight webinars (eight out of ten) you will receive a course completion certificate. the Federal Highway Administration launched the sustainable pavement program in 2010 to invest the knowledge and practice of sustainability related to pavements. the overall objective of the program is to increase the awareness, visibility, and body of knowledge of the sustainability considerations in all stages of the pavement life cycle. the vision and mission of the program was to advance our knowledge and practice of designing, constructing, and maintaining more sustainable pavements through stakeholder engagement. we do hold two meetings per year with our Technical Working Group. and our next meeting will be in Detroit, Michigan the week of November 5th through the 6th. our other goal would be education which we have produced several tools and also trying to get the outreach out in this webinar series is part of that education bullet. our third one is to develop guidance and tools which could be found in our website and our main one would be the towards sustainable pavements program: a reference document. with that I would like to bring up a goal, and we just were just curious to see how many of you have visited the sustainable pavements program website. we just want to get a couple of numbers out there. we will give you 30 seconds to answer our poll question. okay so we have about 37% of our attendees have visited the website and 63 have not. okay. our other poll question would be how did you hear about this webinar series? we have a couple of choices. the sustainable pavements program website, the sustainable payments program email, newsletter, a friend or colleague, or other. we’ll have another 30 seconds to answer this poll. okay, so our numbers have come in and we will look at this a little later. the purpose of this whole question is so we can maximize our outreach opportunities with this webinar series. and now I would like to introduce to you the sustainability ambassadors. these are a group of federal highway employees that will serve as liaisons with the sustainable pavements program and their perspective program area or area of expertise to help promote the practices of designing, constructing, and maintaining more sustainable pavements. with that I would like to introduce our sustainability ambassador who will be giving our webinar today, miss Meesa Otani, moved to the Hawaii division in 2012 as the environmental engineer. she also serves as the area engineer for the kauai district and the City and County of Honolulu. and with that I will transfer the webinar to miss Meesa Otani. (Meesa) Hello everyone. good morning or good afternoon for some of you on the East Coast. I will be talking about the key takeaways of this webinar series. one, we will be talking about the definition and characteristics of pavements of sustainability, the benefits of moving towards sustainable pavement systems. current sustainability practices, emerging trends and technologies, and tools to measure and quantify sustainability. you can find all of this information on our sustainable pavements website with the reference document called toward sustainable pavement systems. what is the sustainable pavement and what happens during the pavement lifecycle? the definition of sustainable pavements that we have come up with is number one is to achieve the engineering goals. it means things like providing mobility (which is lane additions, expansions, or alternate modes), access and smoothness, and other engineering qualities. secondly, we’d like to preserve and ideally restore surrounding ecosystems. this technology is at pavements do impact the surrounding systems; and the goal should be to make them better, not just less destruction to them. third, use financial, human, and environmental resources wisely. we are recognizing that resources are finite, requiring hard choices to sometimes be made. Last, meet basic human needs such as health, safety, equity, employment, comfort, and Happiness. pavements are definitely about us. so it makes sense to meet our needs whenever possible and meet the safety of the traveling public and equity and hiring practices and providing jobs. within these systems it is not too hard to see a simplified definition that recognize three distinct but interrelated systems. the so-called triple bottom-line of environment, human, and economic. what happens in opportunities for improving sustainability throughout the pavement lifecycle? we start with materials production. so this refers to all processes involved in pavement materials acquisition, such as mining or crude oil extraction and processing, which includes refining or manufacturing and mixing. next you have design, which refers to the process of identifying the structural and functional requirements of a pavement for given site conditions such as the climate, existing pavement structure, traffic loadings, and other engineering conditions and then determining the pavement structural composition and accompanying materials. after design, we move into construction which refers to all processes and equipment associated with the construction of pavement systems. generally, construction activities are associated with initial construction as well as subsequent maintenance and rehabilitation efforts. next, we move into the use of the pavement such as interactions with vehicle operations and the environment. a number of key pavement factors such as roughness, deflection, and macrotexture can have large effects on most sustainability metrics including fuel consumption, vehicle operating costs, and associated admissions emissions and energy use. environmental interactions can also impact other sustainability factors such as human health and safety. after use, you move into maintenance and preservation. maintenance and preservation helps slow the rate of deterioration of a pavement by identifying and addressing specific pavement deficiencies that contribute to overall deterioration. finally, we have end of life of a pavement. this can mean different different things to different people. there are three different options, generally for pavements, which could be recycling the materials to be used in a new construction project, reusing the existing pavement and applying a major rehabilitation treatment to it, or disposal of the spent material. FHWA has a series of presentations that touch on each of these stages. so, why should we care about pavement sustainability? we will be talking about why agencies, industry, stakeholders, and just about everyone should care about sustainability. why do roads matter? in the U.S. alone, there are 4 million miles of roads with 2.65 million paved roads. our annual highway and street construction spending is pumps $87.7 billion dollars into the economy. roads also provide the movement of freight, access to school services, and work leisure leisure travel, and overall mobility. and you can see in 2017, there were 3.2 trillion vehicle miles traveled. the highway construction industry also employs approximately 8.6 million people. the benefits of being more sustainable. looking at the economic cost, it includes reduced payment life-cycle costs associated with construction maintenance, overall vehicle operating cost, and crash costs. the environmental component talks about reduce energy, noise, and improved air quality; so, such as energy consumption, greenhouse gas emissions, and also storm water treatment. the social component is improved safety and improved ride and consider conservation of resources. So, how do we consider sustainability in design? as mentioned, sustainability is something that we should all consider. it is a continuum, meaning we consider it throughout the entire lifecycle. it is not an add-on value. you don’t just consider it once as part of, you know, like this is affecting storm water. it’s considered throughout the entire pavement life cycle. it requires innovation and it is also context- sensitive. here are some examples of good engineering practice and sustainability. the blue, you will find is overall social aspects of sustainability priorities. the orange is the economic benefits and the green is the environmental benefit. as I mentioned earlier, sustainability considers all life-cycle stages including materials design and construction through the entire process. it looks for continuous and ongoing improvements. it prioritizes and operationalizes values through a conscious effort. and it is not an add-on value to a system. so, it’s a continuum in which we may be looking to make continuous improvements in all of our processes. it could be incremental at first, but over time we eventually want to be able to achieve positive outcomes. even though even though the definition of sustainability presented earlier really translates into consider everything for a project, it is not possible to do everything. so, organizations and projects have to set priorities within sustainability and do things to support these priorities. it should be at the highest level at which you view a pavement as we said it is not an add-on value or an add-on feature. so some trade-off considerations. as we said, this is where you prioritize. so, improving one outcome may compromise another. you have to consider opportunity cost, which is costs are often difficult to determine. the value of alternatives goes beyond just dollars. be careful when using traditional economic evaluation tools because they may not capture value values beyond money. two things to consider when making trade-offs is priorities and values of the organization or project. choices should be logically related to these. And risk. I know most agencies always talk about the risk presented to the agency and how much risk is that agency willing to absorb? so, risk is what is uncertain and by how much? uncertainty is usually thought of as a negative. can you live with it if the payment surface only lasts five years instead of the hoped-for 10? or perhaps better stated, how much shortfall can you tolerate before the selection selected option is no longer worth it? here’s one consideration of using recycled asphalt pavement versus local aggregate. and, is one more sustainable? so, the benefits of using rap is reduced raw materials use, reduced air emissions, and reduce solid waste because you’re recycling the asphalt pavement and you’re not traveling as far. local materials benefits could include reduced fossil fuel use, reduced air emissions, and improves local economies and reduces cost. however, as we said, it is context-sensitive and it depends. an example is a nearest source of rap is 100 miles away versus acceptable local material is only 5 miles away. so, when you consider that you have to consider the economic, environmental, and societal impacts of material hauling-or as we’ve referred to as the “triple bottom line”. here are some sustainable engineering approaches. Pavement sustainability is not new. the industry has been practicing it for many years. as we talked about, recycling the use of reclaimed asphalt pavement and recycled concrete aggregate in pavement layers. mechanistic- empirical pavement design using ME designs to consider alternative materials, pavement structures, and construction procedures. smoother and quieter pavement surfaces. various options are available to help improve pavement smoothness and reduce tire- pavement noise. there’s also permeable pavement surfaces to help economically handle storm water quality and runoff rates. maintenance and preservation: the use of preventive maintenance treatments to extend extend pavement service life. life-cycle cost analysis. this is a tool to determine the most cost-effective pavement design option from a whole-life perspective that considers initial construction and future maintenance, rehabilitation, and reconstruction action. this analysis may also include user costs which include costs incurred by the road users due to traffic delays resulting from construction activities. value engineering. this is a systematic method to improve the value of the pavement system where value is generally defined as the ratio of function to cost. context-sensitive design. this is something that comes from the 1960’s as a rebuke to the lack of consideration in building highways through cities and rural landscape. it is a highway planning approach that tries to tailor roads to fit the environment for which they are being built by considering the need and purpose of the project. and to ensure that the safety and mobility are addressed while acknowledging scenic, aesthetic, historic, environmental, and other community values. so what are some of the innovations? to achieve more positive outcomes, we looked at innovative use of materials design tools and construction technologies. some of the emerging trends in pavement sustainability include greater use of recycled co-product and waste materials, also known as our RCWMs. improvements in mechanistic-empirical design technologies, such as better models and calibrating it to the local area. application of non-destructive testing. so, instead of doing the traditional coring of pavements, you can do ground-penetrating radar or infrared photography to overcome shortcomings of traditional quality assurance method. the use of non-traditional materials and techniques such as bio-binders, recycled motor oil, or recycled tire rubber for pavement preservation applications. the use of life-cycle assessment techniques to quantify environmental impact of pavement. we will be talking more about the life-cycle assessment as well as everything else related to the triple “bottom line”. as I mentioned, we’re going to continue to talk about how sustainability is context-sensitive. here is a photo of State Route 190 in Death Valley National Park in California. it has two lanes, a very small daily traffic load, and very low annual precipitation. it is the hottest place on earth. in this case, the extreme heat of Death Valley in the summer, which is often well over 120 degrees, it requires almost uniquely high temperature PG grades. solutions like porous pavement for natural drainage may not make sense for a place where there is only 2.4 inches of annual rainfall. whereas, on i-90 near Snoqualmie Pass in Washington State, there this is the Cascade Mountains, which is a very different type of environment. it has much higher traffic, requiring more pavement materials. it is also located higher up in the mountains and subject to more precipitation. while something like a porous pavement might be considered for the precipitation levels, the high traffic volumes and the natural hydrology of the area would make such a pavement a poor choice. and finally, here is an urban area, I-5 in Seattle Washington, where there are 280,000 annual average daily traffic of which 5% are trucks and there is 38 inches of annual precipitation. in an area like Seattle, you would have to consider that your emissions, vehicle safety, and different things like that when considering sustainability and pavement. how do we measure payment sustainability? as I said before, this relates to the “triple bottom line”. of the social, economic, and environmental impacts. to measure your social impacts, the federal highway has a tool called INVEST that is available on our website. there is also a performance testing for both the environmental and economic impacts, such as through life- cycle cost analysis and life-cycle assessment. a life cycle cost analysis measures the cost of a pavement over its entire life to include initial construction, maintenance, rehabilitation, and user costs. it does not measure benefits, and it usually does not monetize much outside of the traditional construction maintenance and traffic costs. a life cycle assessment is a technique that can be used for analyzing and quantifying the environmental impacts of a product a system or process. it is a technique that is evolving and can be used to identify where the most relevant impacts occur and where the most relevant improvements can be made while identifying potential trade-offs to other life cycle phases or impact categories a sustainability rating system is essentially a list of sustainability best practices with an Associated common metric. this metric is usually expressed in terms of points, which quantifies each best practice in a common unit. in this way, the diverse measurement units of sustainability best practices can all be compared using a common unit. The performance tests are a way of evaluating sustainability characteristics such as increased performance, which generally relates to reduced environmental impacts, costs, and reduce social impacts. it includes things such as measuring material properties, system parameters, and performance, usually using laboratory testing and field testing. A life-cycle cost analysis, as I said before, is the measure of cost of pavement over its entire life. so the current FHWA LCCA software is available on our website and it is real cost version 2.5. as I understand, this 1998 LCCA document is actually being reviewed for an update. next, we will talk about lifecycle assessment. this is where you consider the quantifying of the environmental impacts of a product system or process. it shows some more recent guidance on LCA from the FHWA sustainable pavements program. this is different from LCCA, which is costs. an additional “C” means cost, and then LCA is for environment. some example infrastructure or sustainability rating systems include: INVEST as I mentioned, which is the FHWA developed tool; greenroads, envision, and LEED for Neighborhood Development. INVEST and Greenroads are road-specific rating systems; and in general, LEED does not have much applicability to pavements. a sustainability rating system is essentially a list of sustainability best practices with an Associated comment metric. as I mentioned earlier, that metric is usually in point. so, in this way the diverse measurement units of sustainability best practices can all be compared using that common unit of points. these are infrastructure rating systems that could be used for roads and apply somewhat to pavements is envisioned and the LEED for Neighborhood Development. if you are curious about more, the Towards Sustainable Pavement systems: a reference document has a section that that describes what they address about pavement. what are our main reasons for measuring sustainability? number one is achieving sustainability and performance goals. accounting. usually because someone is required to quantify sustainability. it’s to satisfy those mandates. providing providing decision support to help make a decision such as quantifying emissions for each pavement section alternative for a project to aid in selection. process improvement, which is to provide feedback to get better. it’s not really something that can be mandated. and then also, improving the public image of an agency. there are different sustainability initiatives from transportation agencies. one such as the Arizona Department of Transportation. they have a sustainable payments program that they’ve been using for quite a while now, and they actually use life-cycle assessment for their pavement and maintenance program. they are also a big user of the FHWA INVEST tool. in Hawaii, we have a sustainable transportation forum. and then in Minnesota, they have a vision (as part of their sustainability program) to maximize the health of people, environment, and the economy, which like is the “triple bottom line” of social, environmental, and economic impact. in summary… our key takeaways are “sustainable” in the context of pavements refers to system characteristics that encompass a pavement’s ability to: number one achieve engineering goals, number two, preserve ecosystems, three use resources judiciously, and number four meet basic human needs. and it also considers the entire payment life-cycle. as we mentioned before, sustainability is a continuum that should be considered throughout the entire life cycle and not should not be an add-on value. it should really be done from the start since so many of these systems interact in so many ways; and adding features on near the end of design or construction is typically very inefficient. it also requires innovation, is context-sensitive, such as what we reviewed earlier when talking about Death Valley versus I-90 in the Cascade Mountains in Washington State or in an urban area where there is a lot of traffic. sustainability can be measured, such as through the aspects of rating systems, such as life-cycle assessment, life-cycle cost analysis, and other tools; and it includes trade-offs so you would have to prioritize what is important to your agency and what you are willing to sacrifice for that project. the FHWA is sustainable payments program has many resources available to help your agency and provide guidance on this topic. some of our products that have come out of the sustainable pavement program include our guide document which is the Towards sustainable payment systems, the pavement life cycle assessment framework, and we also have some tech briefs on the following topics such as: pavement sustainability, life-cycle assessment, improving resiliency of pavement systems, strategies for improving sustainability of asphalt and concrete pavements. and also, you are starting your sustainable pavements education through participating in our webinar series and there is also a sustainable pavement program roadmap. our upcoming webinars are shown. we hope you can participate in the rest of the webinars in November, December, January, all the way through July of next year. and if you recall, if you do eight hours, you will get a completion certificate. I would also encourage you to check out our website at federal highways, website on sustainable pavements. If you would like up-to-date information, please join our friends list or you may contact heather Dylla (she is in headquarters) or Monica Jurado (who is with our Resource Center). so, with that, if anybody has questions I will turn it over to Kurt to present those. yes, very good. Thank You Meesa. we appreciate that; and we appreciate all the questions that we’ve been getting. we’ll try to work through as many as we can. a couple of announcements before we get into the questions. there seems to have been a few cases where people were not able to see the handout of the presentation. we will send that handout to all attendees via email upon the conclusion of the webinar. we apologize for that. there was also a question that the link to the LCCA document was not functional. we will check that; and we will also provide an updated link to the LCCA document. so with that, we’ve got a number of questions. why don’t we start on them? I’ll start with one first one, there was a question on INVEST. so, exactly what is INVEST? could you describe a little bit more about what INVEST is and what it does and also whether or not INVEST is available for for download. Meese, Heather, or Monica? (Meesa) federal highway’s INVEST tool. INVEST stands for infrastructure voluntary evaluation sustainability tool. it is a web-based, self-evaluation tool comprised of voluntary sustainability best practices, which cover the full lifecycle of transportation services including system planning, project planning, design, and construction and can continue through operations of maintenance. FHWA developed this tool for voluntary use by transportation agencies to access and enhance the sustainability of their projects and programs. as far as I know, it is available for download from the federal highway website. If you just go to our homepage, you probably just click in the search button and look up INVEST or Google just FHWA invest tool. (Kurt) Alright, great. thank you. (Monica) I’m sorry Kurt. there’s also link to download INVEST on our sustainable payments website too. (Kurt) okay, great. and that was that was Monica. so Thank You Monica. let’s move on to our next question. this one is whether we could provide some good starting practices and goals to implement FHWA’s sustainable pavement concept practices for a state highway agency. so in other words, what are some good small steps and good initial practices or ideas to start implementing some of these sustainability concepts? (Meesa) so, I will turn that over to Monica or Heather to answer. (Meesa) yes, our Towards sustainable pavements reference document has a whole chapter in writing or starting up on on goals. and so what we’ve noticed from every different state agency out there, there’s different types of goals; but we do provide some guidance. there’s also a technical brief that kind of outlined some of the goals and potential goals for each depending on their program or what they’re looking for or what is the ultimate goal of why they want to go into a more sustainable route. (Heather) I was going to add that as far as the low-hanging fruit. a lot of those technologies will be covered in these webinar series. we’ll get into more depth. certainly recycling or using more mix asphalt or local materials. they’re all different techniques that are easier, that are common to our industry already, that we could be taking more advantage of, preserving your pavements, etc. so we’ll get into those throughout these webinars and moving forward. what were you going to add Kurt? (Kurt) basically just what you’re saying. a lot of it is the standard practices; but trying to exploit those a little bit more and also recognizing that there may be different issues that are of interest to a particular agency. maybe a particular agency doesn’t have a lot of virgin aggregate materials. so a good starting point for them would be to start exploring the use of some recycled materials, or maybe even in some cases some non-conventional materials to try to help fill that gap. so a lot of it probably kind of depends on what some of the needs are of the agency and what some of the specific goals might be. all right, why don’t we move on to another question kind of related to that. there’s a question: isn’t recycling just the major part of sustainability? (Heather) recycling is certainly a major part of sustainability. we are moving into the assessment side of it though. you want to make sure that it doesn’t compromise the performance and you want to make sure that you’re not hauling the material long distances. and therefore, any benefits or environmental benefits that you would have saved by using that that material are being offset by the energy and materials used to haul that material. it is very context-specific. I think that’s the challenging thing with sustainability is that its context specific and depends on your availability of resources, where the project is, and the specific goals that you’re trying to meet. so, essentially we’re trying to change how engineers think and think about, what are the environmental impacts along with the social impacts of decisions I make? and not just engineering and performance side. but, certainly recycling is one of those strategies. (Kurt) all right, very good. Thank You Heather. another question; and actually somewhat related. are there any laws in place that might prevent agencies from using some of these newer alternative materials that have been mentioned? if not, is it just more of a question of trying to overcome inertia or fear of using new or a new product or fear of the unknown? (discussion as to who will answer) (Heather) i was going to say I’m not aware of any laws that are that make it complicated to do these technologies. there certainly may be some state laws that I’m not aware of that could could come into play and some in certain situations, but I think it’s the the fear of trying something new and in that it’s a risk in rural low-risk community. I think that’s one of the biggest challenges and then education. (Kurt) yes, I totally agree with that and and often then the way around that is to try to implement it. It may be on a small scale. try some pilot projects or some even experimental projects to try to demonstrate that the material can be used successfully. and, anytime we’re talking about these various materials, we always have to make sure that we’re trying to that we’re getting at least the same performance. if we’re not getting the same performance from what we’ve gotten using the more traditional methods, then really we’re kind of taking a step back. so anytime we’re starting to look at some of these newer materials we want to ensure that we’re getting at least the same performance as what we would get using more conventional or traditional type of materials. let’s move on to another question. this one that has to do with whether there are any resources for which of these approaches are cost-effective on a smaller scale project instead of a large-scale projects. in other words do these do these approaches only apply to large-scale project or can we employ some of these approaches or concept on smaller scale projects? this is Meesa. I think it can be applied to any type of project that you have going on. So, a large road project that could be building a completely new alignment or even a smaller reconstruction project; because there are different approaches. you can have different approaches for design, different approaches for testing methods, and different things like that. (Kurt) okay. thank you. moving on to another question. beyond the immediate cost of a certain technical solution, are there sometimes incentives for companies to try to design or come up with designs that are more sustainable? what would force a company, or a contractor, or whoever, to try to come up with more sustainable solutions in today’s low bid environment. (Meesa) I’ll let Monica or Heather answer that question. (Heather) there are different ways that incentives can play a role. I know that through the green rating systems, agencies who are using some of these green rating systems such as INVEST, they use that part of choosing whether it’s contractors are or the type of project and design, they use those; and so there is an incentive that they’re trying to meet a certain private and criteria. those are probably what’s more commonly used nowadays. there is value-added contracting
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so that you could do that and some incentives to the contractors and then through future work and requesting some more labels such as environmental product declarations, which we didn’t get into this presentation and we will get into and some of the later presentations that at the end, actually in July timeframe, July or June. there are labels that could be requested from contractors and ways that agencies could give incentives and start to encourage that behavior. those labels would be a showing the environmental performance of the manufacturing process so, that could encourage contractors as well. (Kurt) very good. Thank You. Heather. next question is whether any of the current measurement systems include the use phase which would also capture then fuel usage as part of that assessment. (Heather) so all three whether its life-cycle costing or life-cycle assessment, can consider the use phase. So that certainly can be done. as far as life-cycle cost analysis tech Bulletin, the 1998 primer, that one did not include the fuel cost based off of certain pavement types. there’s a lot of research in that area, but it did include the excess fuel costs due to detours or work zone construction delay impacts. so that was how that was considered in there. and as far as the lifecycle assessment framework, the use phase goes into many different topics. these are great questions, but they’re questions that we’ll get into more in depth in some of the later sessions from throughout this webinar series. but there’s the issue of urban heat island, the issue of the vehicle fuel emissions, the x-axis vehicle fuel emissions depending on how smooth your pavement is. there’s also the issue of carbonation. so there’s lots of different issues that in the use phase that can come into play on the environmental impact as well. the use phase is highly uncertain then there’s a lot of modeling that goes into effect to to deal with those impacts. so we’re right now trying to figure out what’s the the best science there, and how do we apply those? I do want to put that out into the word of caution that they are highly uncertain right now. (Kurt) right and that is an area right now of very active research. and as you mentioned Heather, we will be getting into that in some of the future webinars. just a quick question about whether the series will discuss parking lots and sidewalks. I guess I’ll just jump in on this one. the focus of these webinars is on on streets, highways, and roadways. so, explicitly, we wont be talking about parking lots and sidewalks. but, there’s no reason that the same general concepts that we talked about in terms of constructing sustainable pavements certainly could apply to parking lot, sidewalks, and other types of pavement type structures as well. so certainly those could be those same concepts can be applied. one general question about how does performance improve overall sustainability? (Heather) performance. as far as the engineering performance if they’re expecting something to last longer and if you’re going to assess the sustainability of the product using life- cycle thinking, certainly something last longer than there’s less money to repair it. potentially. there’s less money required to repair it, then there’s less emissions and materials and environmental impacts. there’s less disruption to the public. so that’s where the performance is key as far as improving sustainability, but it is again context-specific and where you have a heavy traffic volume, potentially that may be where you some of your impact to the traveling public and disruptions that may occur during the construction phase. that may be where you want some of your longer lasting roads because they’re more used. you may have to use other strategies where they’re less traveled, less frequented roadways because you’re going to have to probably use a variety of different solutions. not just one. (Kurt) right. it all kind of ties into longevity. the longer a pavement structure last that you don’t have to do much with it, that certainly has a lot of sustainability benefits because you’re not having to overlay it, provide any kind of traffic lane closures, to apply some of those mid-life rehabilitations. there was also a question about what resources are available that may discuss carbon reductions in concrete pavements specifically. there is a tech brief from FHWA that touches on it. but are there any other resources available that might touch on ways to reduce carbon and greenhouse gas emissions associated with concrete pavements. (Heather) I would look into the reference manual on the the chapter on concrete. the way the reference manual is divided is by the life-cycle phases, as well as by the material component. so, you can find out what they could do at the cement manufacturing if you go into the material production phase, but you could also go to the mix design or the maintenance side of concrete. so there’s many different phases that you could look into that reference document. and there’s a table. It’s a really nice quick table you can look at and reference to see what are different strategies to improve the environmental footprint or carbon emissions of concrete. that’s what I would go to. that’s what we have at FHWA. (Kurt) right and that reference document is available on the the FHWA web page with the link shown on the current slide there (slide 42). a question related to pavement ME design. how is the ME pavement design and sustainability related? how does ME payment design help improve sustainability? (Meesa) I will let Heather answer that, sorry. (Heather) no that’s fine so ME design can allow you to optimize your mix design, so you’re not necessarily over designing something, but you’re also not under designing something. and so anytime we can get better design procedures to design the pavements to the expected use that we want, it is beneficial. so the third webinar, I believe in this period actually will go into depth; and I don’t want to spoil their thunder on the ME design- a little bit more depth than what it is right now. (Kurt) but, but you did hit hit the nail on the head. it is related to trying to come up with more efficient designs, more reliable and accurate designs, for the specific design conditions and considerations. next. we have a question about whether there is any data showing how much more sustainable pavements cost then say a conventional or regular pavement? (Heather) you know, that’s a good question. I wish I even had just what a sustainable pavement is versus the conventional pavement. right now, in another effort, we’re trying to come up with a catalogue of some of what are the best practices that are being done at the different states. but as part of that effort in doing that, one of the ideas was also to start cataloging what are some of the tops of these different strategies that different states are employing. so, I don’t know of anything right now that highlights “here’s what some of the cost differences are of different strategies employed.” we do have case studies that where we are highlighting some of those. so they’re specific case studies, but it’s not at the scale of “here’s every strategy and here’s some of the cost that it saves”. but, once these cases they start getting published- which, if you’re on our email lists, you’ll get access to when these are coming out. they will have some state life-cycle cost savings as well as the environmental impact savings of using these different strategies that we mentioned today and we’ll mention throughout the series. (Kurt) yeah, and I think though it also kind of ties in with what an agency is trying trying to accomplish; and we talked before about the importance of getting good performance and in many cases even having longer life pavements. we’ve seen a number of agencies who have targeted longer life pavements with only a very small/nominal increase in initial cost, but then when you look at overall life-cycle costs, they can demonstrate some very significant cost savings. and although often not quantify. we can also expect to probably see some significant environmental savings as well since the pavement is lasting longer, going virtually untouched, with very little maintenance over an extended 30-, 40-, 50-year period. in many cases, I’d say that there’s not necessarily a big or even a significant increase in cost by trying to adopt some more sustainable strategies. and, I know one agency has even demonstrated that they showed some significant cost savings by adopting what what many people considered some very strong and green-type of initiatives on a major pavement reconstruction program that they had maybe about seven or eight years ago. I don’t know if there’s necessarily always just a significant cost associated with the construction of (I guess what we’re calling) more sustainable pavement structures. moving on; kind of a somewhat related question. how many times can a pavement be recycled? (Heather) I don’t think anybody knows. I think some pavements can continually to be recycled. I mean, it seems like we don’t really have an end of a life of pavement. That’s some of the questions that we’ve tackled a lot at some of our sustainable pavement technical working group discussions. (Kurt) yeah, I think again depending on the pavement type and what you’re dealing with, it just requires that you make sure you’re documenting very well. some of the characteristics of those recycled products that you’re producing, and making sure you’re accounting for those characteristics in the reuse of that recycled material into whatever future application it may be used for. somewhat related to that on slide 20, there is a question about whether we could elaborate a little bit on how RAP reduce the air quality emissions or the air emissions. (Heather) Meesa, do you want to cover that one? (discussion on who will answer) (Heather) with RAP, if you’re using any recycled material, the environmental impacts of the extraction of that raw material and from the previous life are included on the previous life use of that material. so when you when you’re using RAP, you actually are using less virgin material; and because of that- the less virgin material, you have a lower environmental impact in general. those those environmental impacts can be air emissions. it could be their impact to the soil as well as waste. so it’s in general. It’s because you’re using less virgin material. that’s why you have reduced air emissions overall, compared to a pavement that has no rap in it. (Kurt) okay. thank you. and we have a question on whether FHWA would subsidize the use of unconventional materials and a pilot project. that could be one way of trying to encourage agencies to look at these while minimizing some of the risk. (Heather) if there are questions about pilot projects and those additional funding, I would ask that they email Monica or myself because we can get them in contact with the group that deals more with those. that could help with that. because I am aware that there are some funds that do help with some of these types of things, but it’s just not my area. this is Meesa. yeah, if you contact the division office or if you work through the state DOT, there is the state planning and research funding and then also technology transfer funding availability. I don’t know if you’re the state DOT person or you’d have to work with the the local federal highway division office to get more information on how they use those funding sources. (Kurt) okay, and I think we may be bumping up against probably our final question. How about we have a question about using a sustainable pavement in your construction, will that lower the lifespan of your road versus the standard materials that you may use? (Heather) not necessarily. so, when we say sustainability, it’s looking at balancing the performance, your economics with environmental impact. so it doesn’t necessarily mean go throw a bunch of recycled materials in there and then your performance suffers. it’s looking at it all holistically and finding a balance in optimal solution in between. so, it’s kind of hard to answer that question because what’s the definition of a sustainable payment in my eyes doesn’t mean necessarily a pavement that doesn’t meet the same performance. it should idealistically meet those performance metrics, but you’re also looking at optimizing the reduction of your environmental impacts and as well as any societal impacts. (Kurt) right. yeah, I think I think that’s exactly right and that’s on target. we kind of talked a little bit about that previously and one of the other questions. so with that I think we’re bumping right up against our time. so I think we’re going to cut off the questions there. there are several more and what we will do is we will provide responses to those and we will distribute those to all of the attendees to this webinar. so, with that, we thank you very much for your time and attention. we hope you found the webinar and for informative, and we look forward to seeing you again at our next webinar, which is scheduled for November 21st. so, thanks again and have a good day. thank you.

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