Thoughts on the Engineering Industry

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Archive for the tag “application”

Applications of Shape Memory Alloys in Concrete Infrastructure Rehabilation

Hello, I hope everyone is doing well.  I’ve been busy with the holidays but I’m finally going to get back to my blogging and will hopefully maintain my weekly posting schedule this time around.  Today, I would like to talk about some research on applications of shape memory alloy (SMA) in concrete infrastructure rehabilitation being done at University of Houston and Qatar University.

SMA’s are metal alloys that can be deformed and then return back to their original shape when re-heated.  In this case, researchers are testing the usage of SMA’s in a rod that would be wrapped around concrete beams or columns.  Their ability to deform, then return to their original shape, would apply an active confinement pressure.  The design/usage of SMA’s would perform the function of current fiber-reinforced polymers (FRP’s); however, FRP’s only apply a reactive confinement pressure.  The confinement pressure provided by the SMA’s would, in theory, further reduce long-term deterioration and degradation.

The researchers will focus on determining the best available material for concrete columns and beams.  There are three types of metal alloys being tested.  The alloys that are most commonly available are the nickel/titanium alloys, referred to as binary alloys.  Ternary alloys include a third metal in addition to the binary alloy metals.  A third option are the iron- and copper-based alloys, which are generally less expensive.  Since binary alloys require constant heating to have continuous active confinement pressure, the scientist are focusing their studies on a Ternary alloy using Niobium and Iron/Copper alloys.

I believe the application of SMA’s in this application could improve infrastructure rehabilitation.  However, there are some concerns I have.  I think we need to see definitive proof with testing that, by adding the active confinement pressure, we effectively improve the serviceablity life of the infrastructure. The other concern is that we don’t know how much the rods will expand due to creep – especially since the rods will be continuously loaded with an outward force and have already been deformed to a previously outward deformed shape.

What is your opinion on this application for shape memory alloys?  Do you think it will be effective and practical for concrete infrastructure rehabilitation?  If you enjoyed reading, like the post and share it with your friends.  Thanks for your time and have a good week!

Source 

“Shape Memory Alloys Could Bring Stabilizing Force To Concrete Infrastructure”, David Hill, Civil Engineering Magazine, June 2014

Image Source

“Shape Memory and Palladium Iron Alloys”, taboodada.wordpress.com/2011/03/31/41/, March 31, 2011

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Application of 3-D Printing and Modular Design to Construction

Hello everyone, I hope you guys had a good weekend.  Today I would like to discuss a couple innovations which apply 3-D printing and modular design innovations to construction practice.  These are applications that were more common in manufacturing and prototyping initially but can be applied to construction as well according to the article by Business Review Weekly.

The first innovation is the application of 3-D printing to the creation of moulds for precast concrete.  Traditionally, other materials such as wood, foam or rubber have been use, and constructing these moulds could take months to construct.  The Laing O’Rourke Company has developed a method that 3-D prints a large scale wax substrate mould at a rate of 150 kg/hr using a robots.  They have applied this to common projects such as stormwater pipes and have achieved cost savings of 50% to 90%.  Additionally, this solves the waste problem because the wax mould is lifted off or melted away in a water bath after the concrete is cured.  The wax can then be filtered and recycled.

The second innovation is the use of modular components in hospital construction.  Hospitals are one of the most expensive areas of infrastructure because they are individually designed.  Hickory Group has developed a modular panel for use in reception and administrative areas.  These areas use what is referred to as “accommodation components” which constitutes up to 40% of the construction cost of a hospital.  By using the modular panel, construction time can be cut by 40%.  Furthermore, the panels are easily replaceable.  If a panel is damaged, the hospital  can simply order a replacement and have their maintenance worker install the new panel.

Both of these are very good innovations in my opinion.  They are taking methods that have been proven effective in several previously tested applications and expanded their usage.  Furthermore, a reduction in time of construction and cost of maintenance/construction has been achieved.  I would be interested in seeing a more detailed account of the numbers and statistics.   However, based on the information provided, these are great examples of low risk/high reward solutions that can greatly improve construction practices.

What is your opinion on these innovations?  Do you think they’ll be effective?  If you enjoyed reading, like the post and share it with your friends.  Thanks for your time and have a good week!

Sources

Michael Bleby, “BRW Most Innovative Companies 2014: Why Construction Companies Are Thinking Like Manufacturers”, Business Review Weekly, October 9, 2014, http://goo.gl/O0oD6E

Image Source

Anne-Mette Manelius, “Concrete After Dark – Is There An Afterlife for Concrete?”, Concretely, October 17, 2014, http://goo.gl/IYI6q2

Visual Project Management for Construction Managers Using Google Glass?

Hello everyone – sorry about the long break.  I’ve been in the process of moving the last few weeks and I didn’t get internet until about a week ago.  Now that I am almost back to full productivity I should be doing regular posts again.  And now I can look forward to writing some of these posts on my back porch which will be nice too.  Today I want to talk about an application in development for Google Glass which would allow a construction manager to see a visual of future building elements to aid in the construction process. (Article: http://goo.gl/G6audi)

This application has a few benefits that I can foresee.  The main one is that the user can visualize what needs to be done and what it should look like.  I could also see how it would take a complicated construction drawing and help clear up any confusion as to what the specifications should look like.

However, I also see a lot of drawbacks.  The first one is location issues.  If there is any trouble in determining the user’s location, the visual provided will be inaccurate and that is worse than using less convenient methods.  Additionally, creating the model and making sure the users on site are familiar with the tech would be difficult as well.  And finally, I would think that if the application isn’t designed well, information overload and application management could be a hindrance that slows down the work to the point that it out weighs the benefits of having this visual representation.

The benefits gained by having the application aren’t worth the added issues in my opinion.  Combine this with the fact that construction managers should already be able to visualize and build the specifications from construction drawings cause this application to be more trouble than it is worth.  This is not to say that I think technology is not useful on construction sites.  I believe that being able to have a synced database for construction drawings and models would be very useful for a tablet application in a lot of situations.  However, there is only one time I see the Google Glass application being useful and that is for people inexperienced in construction/engineering such as owners to walk around an incomplete project.

What is your opinion on this application?  Are there some different applications for construction managers that would be good for Google Glass?  Thanks for your time and have a good week!

Reference

“Google Glass for Construction?”, ConstruTech, March 18, 2014, http://goo.gl/G6audi

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Orson, Parmy, “Why You’ll See Google-Glass Competitors In Construction Zones Before Starbucks”, Forbes Magazine, March 11, 2013, http://goo.gl/TYBuv

The Application of Biologically Grown Materials to Building Design

Hello everyone, I hope y’all had good weekend.  Today, I want to talk about some new building materials being researched that are biological produced in a replicable process.  One of the common characteristics is that these materials will involve bacteria or something else derived from organisms.  The fact that these materials don’t require significant carbon output is one major benefit.  Another benefit for most of these materials is that they are actively reproduced over time once they are installed as well.  The building materials are described below with some insight on possible benefits and issues.

bioMason Brickshttp://goo.gl/PY68HQ

The bioMason brick is a brick of sand and cementitious material in which the cementitious material is created using a bacteria.  The brick mixture is created and over the course of 5 days the bacteria solidifies into a coral type material with the strength of a normal brick.  The major benefit for this innovation is that it doesn’t require the heat and raw materials used in creating normal bricks; this reduces the cost of the brick by 40%.  They are currently conducting experiments to research bacteria creation using the following materials: urea, salt and yeast extracts, and seawater.

I see this having one major benefit – it would not significantly change the design and build process for masonry.  Masonry strength is mostly determined by the strength of the mortar as long as the masonry unit strength doesn’t change significantly.  The benefits of the bioMason bricks combined with the low technology change requirement makes this much more effective.

Mushroom Insulation Materialhttp://goo.gl/SZcfA

This is a stiff insulation material using plant stalks and husks combined with Mycelium.  There are two forms of application being tested currently: growth inside the wall and spray on insulation.  The insulation is fire resistant and fully compostable.  Additionally, it does not contain formaldehyde or any other harmful organic materials.  This same material can also be used as compostable packaging material.

There are several benefits to this material.  Like before there is no significant change to the other building processes related to it.  It also has great applications outside of this usage alone and is completely compostable once it is not needed anymore.  The only drawback I can potentially see is there being an organic material harmful to humans that is unknown as of yet – similar to what happened with Asbestos. It has great potential overall though – it is my recommendation that more health testing be done before large scale usage.

Self Repairing Concrete:

Research is being conducted on a bacteria that can be used to repair concrete as it ages.  Bacteria engineered to thrive in dry climates is being created to be placed in the concrete mixture.  The bacteria would release Calcium Carbonate as part of the waste process which would fill the holes and cracks over time.

There is one possible major benefit I see – the reduction in maintenance required for the concrete designed this way.  However, more research would be required to determine it’s efficiency.  Additionally, nothing is mentioned about resources and energy required to produce this bacteria; if it requires a high amount of energy and time/raw material resources, it may become impractical to use.  I might also add that the issue of infection might come up here as well; but if the claim is true that it is bacteria that thrives in dry climates, the danger to living organisms would be greatly reduced.

What is your opinion on these possible advancements?  Can you see them being used in the future?  Thank you for your time and have a good week!

Reference:

Wollenhaupt, Gary,”Self-Repairing Concrete Could be the Future of Green Building”, Forbes Online, January 6, 2014, http://goo.gl/IRyzHi

Potential Applications of Cellulose Nanocrystals in Structural Engineering

Hello everyone! Today, I am going to take a break on my Karuna House series and write a post about cellulose nanocrystals.  Cellulouse nanocrystals are the material that gives plants and trees their stiffness. Their dimensions are 3 nanometers wide by 500 nanometers long – about .1% the width of a grain of sand.  They can be easily harvested with a sustainable process and can be produced from paper waste as well.  A recent study by Purdue University has found that these nanocrystals are light weight, have high strength, are highly resistant and have the stiffness of steel.  “It (the research) is also the first step towards a multiscale modeling approach to understand and predict the behavior of individual crystals, the interaction between them, and their interaction with other materials,” Zavattieri said. “This is important for the design of novel cellulose-based materials as other research groups are considering them for a huge variety of applications, ranging from electronics and medical devices to structural components for the automotive, civil and aerospace industries.”  The article shown in the link here, http://goo.gl/8Pl8LB, provides a quick overview of characteristics with extremely basic explanations in regards to applications and I am going to expand on possible applications as they pertain to structural engineering.

Organic Polymer for Concrete:

     Fiber reinforced concrete can be designed to reduce the amount of steel required.  In this way, cost and heavy material requirements can be reduced in the construction process.  I believe that cellulose nanocrystals can be used in the same way.  They can be placed in concrete and improve the tension strength where needed.  These also have the added benefit of being more sustainable and less expensive in regards to material accessibility as compared to fiber reinforcement.  That being said, it is not clear if the cost of the production once the material is obtained would be out-weigh the cost savings in accessibility.  More research and practical application of the production process is needed to determine that.

Reinforcement Against Cracking:

A very common issue with concrete infrastructure is cracking.  Currently, when cracking starts occurring at the base of a beam, a method where steel reinforcement is bolted into the concrete is used to prevent further expansion of the cracks.  While it is an efficient solution in regards to time and money, steel is not as environmentally friendly a material.  Along with that, once research into production and application is completed, the amount of time and money can be reduced to that of the steel reinforcement method.  This means that an approach where an organic polymer sheet covered by a layer shotcrete could be a better solution at that point.

Additional Reinforcement for Timber Structures:

Engineered lumber is a recent development in timber design.  These are basic timber building elements that are created from pieces of timber.  Some good examples of this are cross laminated timber/particle board panels and glulam beams /columns.  Along with that, other applications such timber restoration apply this same concept of combining pieces of timber to create a stronger building element.  The same type of organic polymer sheet used for reinforcement against cracking could also be used to provide some extra tension strength in these situations.  This would be very beneficial in timber elements that are designed to resist high levels of flexure.  Another added benefit would be that the nanocrystals are extremely thin and can be applied in design with very tight tolerances.

Cellulose nanocrystals could have a lot promising a applications for structural engineering designs and I look forward to seeing what improvement can be made using this material.  What is your opinion on the possible applications mentioned above?  Are there any other structural engineering applications that you can see this material for?  Thanks for your time and have a good week!

Sources:

Zavattieri, Pablo. “Cellulose Crystals Are a Possible ‘Green’ Wonder Material.” Red Orbit Online.  December 17, 2013. http://goo.gl/8Pl8LB

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