Thoughts on the Engineering Industry

A blog covering engineering, technology and business topics

Archive for the tag “transportation”

Benefits of Reusing Composite Shingles in Asphalt Roadway Construction

Hello everyone! I hope y’all have been doing well.  Today, I want to talk about an interesting innovation I read about the construction of O’Hare Airport. (http://goo.gl/WjI8Ek)  They collected used composite asphalt shingles and used them as part of the asphalt binder in the runway and various road type structures for the facility.  In this post, I will outline the process and the benefits.

 
The process:
Old Shingles Are Collected:
First, shingles are collected for reuse in the system.  At first, there weren’t any incentives added to motivate people to recycle used shingles.  However, some incentives have been created through different programs in various locations – all them outlined in the article.  One of them is a ban on sending large amounts of shingles to the landfill.  Another concept is an increased charge for disposing of shingles as compared to providing them for reuse.  The only exception is shingles that incorporate asbestos in their production and various limitations are discussed for reducing that risk.  Overall, the incentives seemed effective in my opinion.
 
Shingles are mixed into a pure asphalt binder:
The next step is that shingles are ground up and melted.  Once melted, this product can be added to the pure asphalt binder to increase the volume of this asphalt binder product.  At O’Hare airport, the shingles made up a 3% percent portion.  This didn’t make a huge dent in the budget but depending on the project it could reduce costs more.  Statistics and comparisons are provided in the article.
 
Asphalt is Laid Like Normal:
The asphalt binder and resulting asphalt is used like before.  As long as any differences in material properties are accounted for, the design and construction remains the same.  This results in an easy implementation on the construction and design side of the process.
 
The Benefits:
Reduced Use of Oil:
Oil is a precious commodity; anytime it’s usage is reduced, I consider it a good thing.  Along with that, it is easier to get a hold of used shingles than oil.  For both of these reasons, I consider the reduced oil usage a considerable benefit.
 
Reduced Cost:
The cost of using reused shingles is lower than using a pure asphalt binder.  Unless the scale is large, it is a minimal cost difference.  However, considering the scale of infrastructure cost these days and the amount of repairs needed, the scale is large enough that it would make a difference.
 
Reduced Waste:
These shingles, if not used in this capacity, would most likely be going to a landfill.  The lack of landfill space and shear quantity of human waste going to landfills is a current issue and reducing the amount from the housing would be a large contribution towards reducing that waste.
 
What is your opinion on the usage of this mixed asphalt binder?  Does it provide enough benefits to outweigh the cost and effort of changing the process?  Are there any noteworthy drawbacks or additional benefits not mentioned?  Thanks for your time and have a good week!
 
Sources:
Jon Hilkevitch, “Getting Around: Old Shingles Get New Life on O’Hare Runway”, Chicago Tribune News, June 30, 2014, http://goo.gl/WjI8Ek
 
Image Source:
“Why Homeowners Should Choose Asphalt Roofing Shingles Recycling”, Asphalt Roofing Shingles Recycling, October 18, 2012, http://goo.gl/u9l7cD
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The Balance of Public Private Partnership and Government Funding in the Infrastructure Industry

 

     Hello everyone, sorry about being away for a bit.  I had an exam and had to focus in on school work, but I feel like I did good on the exam and can get back to a normal rhythm.  Today I would like to pose an interesting question.  What is best for the infrastructure industry – public private partnerships or government funded projects?

     I read a good letter-to-the-editor piece in CE Magazine recently that was critical of politicians who only wanted to pursue the infrastructure investment bank option for increasing investment.  In the author’s opinion, it is the job of the government to do whatever it takes to provide the infrastructure systems for this country.  I don’t see it as one dimensional as the author does, but this brought an interesting point to my attention.  A lot of people involved with the infrastructure industry like the public private partnership type projects as a way to bring more investment to the infrastructure construction and maintenance process.  Since increased funding in this area is needed ASAP, I have no problem with them pushing for this option if people are willing to do this.  However, issues in the infrastructure industry that can’t be addressed through a public private partnership system are largely over looked.

    Public Private Partnerships can help relieve a lot of the issues that drag our infrastructure down right now.  For example, a private company could charge tolls for a road and use that to maintain the road as part of a business plan.  This is a great system once you solve the oversight and standards issues.  Another area that this could be beneficial for is management of projects and procuring construction manpower and equipment.  As people have discovered with the government projects, having to maintain a large bureaucracy in managing these large projects is expensive.  Off loading those expenses to companies willing to do the work would allow for increased efficiency in the infrastructure construction process.

    However, there are some parts of the infrastructure industry where government investment is required to some degree.  The main one I see is the initial investment stage of these large scale projects.  Any private company will need some help (or at least an incentive) to take on the large amount of initial investment required.  Private businesses in general prefer projects that have large profits and the lowest possible expenses.  Government can provide a lot of aid to the infrastructure industry by allowing private companies to apply their preferred model for business.  The other area I see the government being essential are the parts of infrastructure where for profit motives aren’t the bottom line.  A great example of this is public transportation.  Overall, it is a largely inefficient industry in regards to cost and maintenance.  However, it doesn’t mean that it is something that shouldn’t be promoted as a part of our infrastructure improvement plan.  I’m not saying that we should take a loss in these projects, but it is something that should be offered without an eye towards massively cutting cost or increasing profits.  Since a company will not see the same high margin of profits they might find in a large highway construction project, they are more like to not take the project or to maintain an inadequate system due to their goals of minimizing inefficiencies and increasing profits.

    To sum it up, a balance needs to found between the application of public private partnerships and government funded projects in the infrastructure industry.  Some of the ways I think we can find a good balance are listed above.  What is your opinion about the balance of the infrastructure industry?  Is there anything you think we need to do to improve it?  Thanks for your time and have a good week!

Start Up Plans and Revisions for the Hyperloop Design

Hello everyone! I hope y’all are doing well.  It’s the same old stuff for me.  Looking forward to Halloween though– it’s always my favorite holiday.  And I want to go to a haunted house since I haven’t been to one in a long time.  Today, I want to talk about updates on the hyperloop concept since Elon Musk has made the proposal.

JumpStartFund has recruited two people, Marco Villa (former director of operations missions at SpaceX) and Patricia Galloway (first female president of ASCE) to coordinate the month long fund raising process.  Dirk Ahlborn, CEO and co-founder of JumpStartFund, has said “a lot of people talk about why this project will never work and how difficult it is to realize,…We are honored to have Dr. Villa and Dr. Galloway on board to lead our community, and their involvement goes a long way to proving that our platform’s processes, along with our community, can actually bring mega projects to life, such as Hyperloop.”  This fundraising is unique in that JumpStartFund will apply concepts of crowd space design used in the design of open-source software.  Galloway is interested in the project because it offers some unique challenges.  According to her, the challenge in this stage of the project is to verify its viability and prove that it can be practically designed and constructed.  They will have to bring people into the project that can not only bring in useful expertise but some much needed equity as well.  Galloway said “I believe this project will revolutionize how transportation will be viewed for future travel to and from major cities similar to the way the Concorde almost changed air travel,…What is different today is the opportunities that crowdsourcing and crowdfunding offers in getting dreams and innovations off the ground to allow the Concordes of the future become reality today.”

The Technology Futurist of AutoDesk, Jordan Brandt, has also added some significant input as well.  He says “Elon Musk put a lot of this energy into designing the pod capsule, and the power requirements, and things like that,…but not so much into the infrastructure, which by the way is the most expensive aspect of the project.”  Using 3-D modeling software, Brandt has redesigned the tubes such that they are stacked in a vertical figure 8 design.  According to his calculations, this should reduce land area requirements and the quantity of pylons needed to support the tubes.  Along with other engineers at AutoDesk, he also devised a system, called a mobile braiding system, which would use carbon nanofibers to create the tubes as it moves along the planned route.  With a refinement in the carbon nanofiber manufacturing process the material could be cheaper and the transportation for the construction costs could be greatly reduced as well.  In his final estimate, he believes this will save billions of dollars on the project.

In my opinion, these are the types of innovations I was hoping would be made on the design.  In my previous blog post (http://goo.gl/X1UgIK, second to last paragraph), I cited construction costs as one of the critical issues to address and this is an innovative idea.  I worry that the refinements in manufacturing the carbon nanofiber might not be as effective as thought and I also worry about the need to create yet another untested machine to complete the project.  However, these are the types of creative ideas that I think are needed in transportation design going forward.

What are your thoughts on these new developments?  Do they help or hurt the viability and the implementation of the project?  Thanks for your time and have a good week!

Sources:

Rogowski, Mark, “With Engineers On Board, A Startup Is Driving The Hyperloop Idea Forward”, Forbes Online, 9/26/2013, http://goo.gl/uMjgGH

Jessica Leber, “What Will It Take to Actually Build the Hyperloop?”, Co.exist, 10/10/2013, http://goo.gl/j3ESai

Basic Overview of the Hyperloop

Hello everyone, I hope y’all are doing well.  I’ve taken a bit of a vacation, both literally for a weekend, and then for longer in regards to my blog.  I feel guilty but it just felt like the right time to do something like this.  Nothing else new has really been going on with me – still just looking for work as an engineer and keeping my resume up to date.  I have taken the time to really learn Revit which should help me and my next big to do list in regards to personal learning is getting sharp on AutoCAD again.  One fun thing is that I’m also working harder on getting my Spanish to a conversational level, it would really be nice if I could put that on my resume too although not as important.  I will also start working as a substitute teacher again and I hope that won’t cut into my job hunt and personal job training right now.  We’ll see how that goes.  Anyways, that’s about all as far as updates go – today, I want to talk about the recent Hyperloop Alpha Proposal published by Elon Musk (founder of Paypal, SpaceX and Tesla Motors).  It has created quite the stir in the engineering community and I thought it would be a good topic to come back on. For this blog post, I am going to reference Elon Musk’s Hyperloop Alpha Proposal (http://bit.ly/16LCXwt).  However, this is a complex enough idea with enough attention that I might do some more detailed analysis in another blog post.

The hyperloop is a combination of a maglev and vacuum tube system.  Similar concepts have been proposed by Rand Corporation and ET3.  The main difference is that the previous designs involve using a hard or near hard vacuum in the tube; however, the Hyperloop uses a low pressure system.  The low pressure system is supposed to be much easier to maintain using standard pumps and maintenance than a hard vacuum.  The propulsion system involves a combination of air pumps and magnetic levitation.  An air pump will be put in the front of the train and will pump air below and behind the train.  This will accomplish several things: reduce air pressure in front of the train, create a buffer of air below the train, and reduce drag behind the train.  A pump will also be used directly below the train to reinforce the buffer of air as needed.  The maglev system will propel the train forward and will be powered by a battery similar to the battery found in the Tesla Model S.  There are two options for the size and purpose of the train: one is a smaller passenger train and one that is a larger passenger train that can also carry several vehicles.  The Hyperloop is theoretically designed to travel at 700 mph according to the proposal.  However, the critical part of this design not the propulsion system but the tube system.  The proposal suggests a tube system that is supported above ground using precast reinforced concrete columns that would take up no more room than a power line pole would require.  The track would follow the I-5 Highway and only deviate from the highway when necessary.  Also, due to changes in elevation, it is estimated that the tube would occasionally have to be placed at or below grade.  The track would be stabilized using dampers and minor adjustments would be allowed for to account for foundation settlement.  The different sections track would be connected using expansion and contraction joints that would help account for lateral loads due to earthquakes and other lateral vibrations.  The rest of the report is numbers and calculations used for estimation and comparison in regards to other systems.  The specific numbers and calculations read like a rough estimate and aren’t worth discussing in this post in my opinion; however, I would recommend quickly browsing the numbers and calculations just to get a quick idea about the comparisons to other modes of transportation.  Elon Musk in closing goes on to list the critical issues that need to be considered to implement the idea:

“The authors recognize the need for additional work, including but not limited to:

1. More expansion on the control mechanism for Hyperloop capsules, including attitude thruster or control moment gyros.

2. Detailed station designs with loading and unloading of both passenger and passenger plus vehicle versions of the Hyperloop capsules.

3. Trades comparing the costs and benefits of Hyperloop with more conventional magnetic levitation systems.

4. Sub-scale testing based on a further optimized design to demonstrate the physics of Hyperloop.

Engineering News Record wrote an article (http://bit.ly/1a7MWQQ) recently sharing some professional critiques.  The first one is a quote from an unnamed source:

“Many media sources offer commentary from professors about the impossibility of the hyperloop. One of those same sources told ENR off the record that “the idea of building a $68-billion rail line that takes 25 to 30 years to complete is just as absurd.””

They go on to say that Elon Musk has addressed the issue that testing and further research is required, but that some blow back has come his way for that.

“Other media critique Musk for being only an idea man who is hiding behind his massive business responsibilities and not moving toward implementation of the hyperloop. Musk admits as much in his proposal and, noting that the hyperloop idea is not complete, asks for help from “all members of the community.””

The article then goes on to share some thoughts Ted Zoli of HNTB, National Chief Bridge Engineer.

““Just the substructure costs alone for elevated structure over the entire length of the alignment is enormous,” says Ted Zoli, national bridge chief engineer at HNTB. The hyperloop’s proposed design requires elevated piers every 100 ft. Zoli says if the structure was built instead at grade, the construction costs could be “sharply reduced.” He adds that it conceivably could be built at grade for much of the route, “particularly if it is in the median of I-5,” which is where Musk envisions much of the transit tube being placed.

Zoli suggested that, given the hyperloop’s 88-in.-dia passenger pipe, any necessary tunneling could be done with horizontal directional drilling (HDD), “an inexpensive pipe installation technique.” Zoli adds that the largest HDD done now is 56 in. in dia, but he thinks custom HDD equipment readily could be developed, given the size of the hyperloop project.””

In closing, a final addition to the list of concerns is added in reference to another comment by Ted Zoli.

“5. A closer look at expansion joints.

“The expansion joints have not been figured in, in any meaningful way, and would be required much more often than at the terminal stations [as the current proposal outlines]. I would expect something on the order of every mile or thereabouts, even with a telescoping connection. Bearings would also have to accommodate relatively large relative movements for this distance between expansion joints,” says Zoli.”

In my opinion, there will be several critical issues if this is pursued.  The main one is the tube system in regards to column supports or on grade and expansion and contraction joints.  Given the high portion of the budget it involves, the high maintenance cost, even if it is designed well, could make it infeasible.  That combined with the earthquake and dynamics issues make that the most critical issue.  Another possible issue is testing – this is a system that has never been used on this scale before and would need significantly more testing and research to make a final decision, both of which cost money and won’t magically happen overnight.  And the final issue I see that has not been mentioned in the article at all is the reticence of the government to use unproven systems.  Take a look at how long it has taken to get high speed rail going in California and that is a system that has been proven to work for a couple decades in other countries.

Well this post got longer than I expected for my first post back in a while but thanks for reading if you got to this point.  What are your thoughts on the Hyperloop?  Do you have any concerns about the hyperloop?  Do you think this system can realistically be designed and implemented?  Thanks for your time and have a good week.

New Landmark Bridge for Downtown Fort Worth

Hello everyone, I hope y’all are doing well.  Not much has changed with me…still looking for work and I am also making a solid effort to brush up on some structural engineering programs like Revit, SAP, and AutoCAD.  Today I want to share my opinion on a new bridge that is going up in my hometown of Fort Worth, TX.  Part of it is for selfish reasons –  it is my hometown and I am glad we are getting a fancy new bridge for an up and coming area of town.  However, it also uses a unique combination of bridge design concepts I would like to discuss.

The design of the bridge is a combination of two common bridge design concepts – a network-arch bridge and a precast concrete bridge.  The city wanted a network-arch bridge to add aesthetic appeal to the design.  However, they wanted minimal disruption in regards to traffic – hence application of precast concrete principals.  The article gives the following specifications for the bridge: “The bridge is a series of 12 post-tensioned concrete arches, six on each side, which are the main structural elements. Each arch is 163 feet long and over 23 feet tall. While the new bridge will remain with four traffic lanes, it will be much wider to incorporate lanes outside the arches for pedestrians and cyclists.”  The goal was to reduce the on site construction site down to 150 days.

To do this, the arches were cast on their side for efficiency.  Post tensioning was applied in three stages.  The arch was cast sideways and post tensioning was applied, the the arch tilted up right and another round of post tensioning was done.  Then the arch was moved into storage and a final round of post tensioning was done.  The casting process took between 3 to 6 weeks; while this was being done, the foundation and columns were constructed on site.  Transport and installation of the arches started in July and will finish by October.

Personally speaking, I like the bridge design and location.  The bridge will connect the up and coming West 7th District with downtown Fort Worth which should guarantee good visibility.  Along with that, the creative design process and improved construction time is also impressive.  This should make the bridge a good icon that can be advertised for the Fort Worth area.  The only drawback I could see is that the new combination of design concepts may not work as well as expected.  I trust that it can initially handle the dead loads and traffic live loads adequately so safety isn’t a major concern for me.  However, the lifetime demands like fatigue, deflection over time, etc. are more difficult to predict and can’t be tested as accurately – especially with uncommon designs like this.

What are your thoughts on the bridge?  Do you think the design will be effective?  And on a personal note, if you have been to downtown Fort Worth or West 7th Street district, do you think the bridge will be a good addition to the area?  Thanks for your time and have a good weekend.

Source:

Nancy S. Giges, “World’s First Precast Network-Arch Bridge”, www.asme.org, http://tinyurl.com/n7wblwa

Improving Our Infrastructure to Be Competitive as a Nation

Hello everyone, I have been away from my blog because I was on vacation the last two weekends.  However, now I am back and feeling good.  I finally took my comprehensive exam for my ME program and I am now just waiting to formalize the graduation process.  I probably won’t walk across the stage but it feels good to know all my education is done.  I can now focus on finding work and some other personal education stuff. (like learning Spanish, how to use Revitt, etc.)  Today I want to talk about improving our infrastructure so that it can be the best in the world.

I was just reading this article (“Can ‘D+’ in infrastructure lead to ‘A’ in economics?”, http://tinyurl.com/lfxn4kt) earlier this week and it really made me rethink the whole infrastructure improvement concept.  For a while now, I have been a proponent of improving our infrastructure so that it will improve the economy and give us the much needed infrastructure repairs that are needed.  As someone who lives in Texas, I can tell you a lot needs to be done here and this is one of the places that is better in regards to infrastructure.  However, this article put it in a light that I think is important – how we can use the opportunity to surpass other countries with a system overhaul.

Our infrastructure is ranked at a D+ right now by ASCE – definitely not a good grade and one that needs to be improved.  And I think that instead of just repairing it like it was before, this complete repair of the whole system that is needed gives us a great opportunity.  We can put in new and improved roads, public transportation, energy grids, monitoring technology, etc. into every new road, rail, or energy system.  As soon as I read the article I thought of this analogy – getting a new car.  Going out and getting a car that looks exactly like your old car without any new features seems a little wasteful right.  If you are like most people you have had your car at least 5 years, and by then a lot of improvements have been made and can be implemented for the same price as buying the same car you had before.  That’s the logic we need to apply now.

The article outlines three main areas that the author thought that we can easily do some upgrades.  The first idea is in interconnected public transportation.  This is something I have talked about for years amongst my friends.  Having interconnected hubs of planes, trains, buses and any other modes of public transit would greatly improve traffic flow on roads and allow people to travel easier.  Places like California have already started and I think it’s something that needs to be done all across the country.  The second idea is a micro-grid energy system that can work together with other systems or work independently.  This would give the system freedom to disconnect if needed in an emergency or work together and share excess energy in peak usage hours as needed.  A good example of this is a neighborhood in Brooklyn which could operate during Hurricane Sandy by disconnecting their micro-grid system from the larger system.  The last idea is increasing efficiency in newer buildings.  When building new buildings or renovating old buildings, money is already being spent to get new materials.  By using systems that are more energy efficient and environmentally friendly, improvements in energy and resource usage can be obtained for very little extra cost.

Do you think that these ideas will help improve our infrastructure?  What are some other ways that you think we can improve our infrastructure?  Thanks for your time and have a good week!

Internally Cured Concrete as a Solution to Cracking and Lifecycle Issues in Bridge Decks

Hello everyone, I hope y’all are doing well.  I had a pretty good week.  The school year for the school district is winding down so I should only have a few days of substitute teaching left and then a long summer break.  I also know for sure now that I can register for my comprehensive exam and I already know the test date – once that is done I can apply for graduation on my Masters of Engineering program.  I also just got back from floating the river in Gruene, TX which I haven’t done in ages.  All in all, things are looking up.  Today I want to talk about an innovation in curing concrete being researched at Purdue University which could significantly reduce cracks in concrete bridge decks.

The concept being researched is a high strength concrete being cured using an internal curing process and the research shows that it could double the life of the bridge deck.  The concept was first discovered in high strength concrete by Dr. Jason Weiss in 2004.  Further research by Dr. Weiss also showed that there could be a lot of potential uses for moderate grade concrete as well.  The normal curing process works by adding the aggregate, cement mix and water separately.  The way internal curing works is that highly porous aggregate with moisture and cement mix are combined and the curing process occurs from the inside out as the water is pulled out of the aggregate by the cement mix.

Once the appropriate proportions were determined, samples were tested for salt ingress, corrosion and cracking.  The material has now passed the test on samples 15 ft. long and 3 ft. wide.  Along with that, a few bridges built by INDOT have used internally cured concrete as well and they seem to be holding up.  INDOT believes this curing process has potential and plans on moving into full scale field trials while also trying to gain more accurate information on life cycle data.

However, there are a couple challenges with this new process as well.  One challenge is that moisture content of aggregate is much more critical.  It may seem like an easy issue to account for; but if the crew doesn’t have the training to account for this, it could make it more difficult to construct.  The other is that there is a slightly increased up front cost as compared to the traditional process; however, Dr. Weiss believes that the large decrease in maintenance cost in the future should make up for that.

Overall, I believe that this is a promising improvement in the bridge deck curing process.  Not only does it reduce cracking and maintenance cost; it also increases the lifetime of a bridge deck.  Along with that, there is a lack of resources in regards to construction crews and budgets – implementing this process could do a lot to ease the load in both of these areas.  What is your opinion on internally cured concrete?  Do you think the benefits projected by Dr. Weiss are too optimistic, not optimistic enough or mostly accurate?  Thank you for your time and have a good weekend!

 

Source:

“Internally Cured Concrete May Lead to Crack-Resistant Bridge Decks”, Civil Engineering Magazine, May 2013, pg 36-37

Can a study on Texas infrastructure ignore public transportation concerns?

Hello everyone, I hope your week went well.  I actually felt a little off in the middle of the week due to grass allergies which is annoying.  I did have a bit a good luck though in getting a job interview for a small structural engineering firm in Dallas.  It turns out he was looking for someone who knew revit though which I don’t know, but it gives me something to work on for the future and he did recommend a good tutorial book which I appreciate.  Overall, the experience was good.  Today I wanted to share with you an article I found talking about how Texas has the best infrastructure in the country.  When it comes to roads, I could find it believe-able but I think there is something essential that is not mentioned even in passing – our severe lack of public transportation options in places.

In the study by CNBC, they say that they “measured each state’s transportation system by the value of goods shipped by air, land and water.  The availability of air travel and the quality of the roads in each state were also examined.”  I’ll grant them one thing – this is an easy statistic to quantify.  It takes a lot more effort to do an in depth study of the number of commuters combined with all the transportation options and travel times to see a complete picture.  That, however, is not my issue.  It’s the fact that they neglect to mention this element they over looked at all.  The only thing they say that is closely related to this fact at all is this – “Despite Texas’ number one ranking in terms of the value of items shipped over its transportation system, North Texas drivers are dealing with some high numbers of their own as they contend with the most congested freeways in the state.  A 2011 study by TxDOT found that the LBJ Freeway carries more than 300,000 cars per day despite being built to handle only 120,000.”  I don’t see how you say that you are proud of your infrastructure and claim that it is meeting your states need when the roads are only designed to meet a fraction of the demand.  Not only that, they look into the topic any deeper on any level; if they did, I would think they would find research like this or this.  Even if the original assessment by CNBC is accurate by their standards, their choice to ignore the transportation system as a whole makes the conclusions in the study highly flawed.

What is your opinion on this?  Should studies like this be done as long as other elements are considered as well?  Or do studies like this always lead to a flawed analysis like in this article?  Thanks for reading and have a good week. 🙂

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