Thoughts on the Engineering Industry

A blog covering engineering, technology and business topics

Archive for the tag “building”

3-D Printed Buildings Elements Created from Building Construction Waste

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     Hello everyone, I hope y’all have been doing well.  Today I would like to talk about an improved application of 3D in building construction.  For a while now, 3-D printing has been applied to building construction on a smaller scale.  However, the large portion of the structure has still been constructed using conventional methods.  Experts in various fields of building design and construction have been researching applications that expand the usage of 3-D printing in building construction.  This is an area of building construction expertise in which China has recently lead the global market according to Brittney Stevenson.

In April 2014, WinSun Decoration Design Engineering Co. revealed that 10 homes were constructed entirely out of a 3-D printed, recycled concrete material – an advancement that surprised the engineering and construction community.  In January 2015, it was revealed that WinSun had made further advancements in the applications of this 3-D printed material.  A 6-story apartment building and home has been constructed and the apartment building itself has an approximately 1,100 square meter floor plan.

The 3-D printed elements were created by inputing a CAD file into a 20′ tall, 33′ ft wide, and 132′ foot long machine printed using a concrete mixture.  The concrete mixture includes concrete, fiberglass, sand and a hardening agent.  The usage of this material allows for improved reusage of general construction waste while also being flexible, self-insulating and resistant to earthquakes.  Reinforcement was used where further strength was required and some of the larger pieces were built off site and transported there.  Details of the of building construction process are listed in the article.  According to WinSun, they are able to save 60% of the materials required for home construction, construct the building in 30% less time than traditional construction and reduce the required labor by 80%.

These are impressive results if true.  I still wonder about the expense of owning and maintaining the machine might be a hindrance at first. And I would hope the cost of collecting the construction waste and creating the concrete mixture is included in those statistics.  I think this is a good innovation, especially for low rise buildings since the loads and stresses are lower (although I believe a 6 story building is pushing the limits of standard low rise construction).  I would be interested to see how the material ages in regards to long term durability as well.  Overall, there are several applications that this would be useful for in the building construction industry.

What your thoughts on 3-D printed building elements? What about the concrete mixture used?  Have you heard of any other building materials being used in relation to 3-D printing?  If you enjoyed the article, please like it and share it with your friends.  Thanks for reading and have a good week!

Source

Brittney Stevenson, “Shanghai-Based WinSun 3D Prints 6-Story Apartment Building and an Incredible Home”, 3D Printer & 3D Printing News, January 18, 2015, http://goo.gl/TwVSKC

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Development of Transparent Concrete

litracon 1 Concrete Innovation Part 3: Design transparent inflatable Concrete Cement

Hello everyone! I hope the last couple of weeks has gone well.  I was preoccupied with a small vacation, school stuff, and having to get a new vehicle since my car was totaled.  However, I hope to get back on schedule after this.  Today, I would like to talk about a new development in concrete technology: concrete designed to be transparent.

According to the article by Giatec Scientific, the concrete mixture is modified such that 4 to 15 percent of the mix is fiber optics materials.  Ideas for transparent concrete since 1935; however, serious development had not been pursued until 2001 by Áron Losonczi for use in his architectural designs.  In 2004, production was started for other commercial usage as a type of concrete called “Litracon.”  Since then, other competitors have developed similar designs.  These products have been used with back-lighting or natural light.

I think the concept is very interesting.  It’s something I would probably enjoy working with or using in a design.  The aesthetics would be amazing to see and I like the idea that it could be used in circumstances where you need more stiffness than a big window could provide.  The situation would be similar to structures that use the glass masonry units.  There are however some issues I can see. One is when and where can it be used safely.  The article mentioned examples where it’s used in floors and floors can see a lot of loading in certain types of situations, i.e. stadiums or concert halls.  The other issue I see is behavior of over time.  Will the bonding of the cement hold up in a mixture with that much of a potential void ratio?  Even if it holds up in regards to it’s initial bonding, will the mechanical strength related properties such as creep and general durability such as cracking be reduced?  Along with that, I would imagine the aesthetics have to hold up as well.

What are your thoughts on the idea of transparent concrete?  Is it something that is practical to use in building design?  If you enjoyed the blog post, feel free to like it and share it with your friends.  Thanks for your time and have a good week!

References

Giatec Scientific, “Concrete Innovation Part 3: Design”, http://goo.gl/Ee7VBo

Benefits of BIM Modeling in Project Pricing for Head Contractors and Subcontractors

     Hello.  How is everyone doing?  Today I would like to discuss the statistical breakdown of the benefits in project pricing BIM modeling can provide for the head contractors and subcontractors involved in the design process.  BIM modeling is something that is collectively touted by most innovators in the building and infrastructure design/build field.  However, it would be helpful to understand who has the most motivation to implement improved BIM modeling.  As stated by David Mitchell, “For different types of projects the people you need to engage, changes. We need to acknowledge that the savings arising out of a building project differs significantly to those of a civil or resource project.  There also needs to be an appreciation of when a construction contract or subcontract is formed as well as the type of construction contract that has been entered into.”  Therefore, the issue is approached in regards to those factors.

For a commercial scale building project, the indirect cost such as design and overhead management amounts to 17% as compared to 83% for the construction costs.  In addition, the ratio of margins between subcontractors and contractors is 7 to 1.  Therefore, it benefits the subcontractors the most to apply the BIM modeling.  However, when a civil project is considered, the head contractor sees most of the benefits because subcontractors only control 17% of the costs.  The resource sector has some interesting statistics as well.  First of all, for a pipeline, the indirect cost is far greater at 45% of the cost going to head contractors.  In addition, the head contractor owns the material production plant/labor and the resulting cost accounts for 83% percent of the other 55% which amounts to an additional 46% of the direct cost and 91% of the overall cost.  Therefore, in this case, the head contractor holds a large portion of the cost control.  However, when building a refinement plant there are some critical differences.  There is a similar level of indirect cost cost at 45%, but the subcontractor sees 88% of the direct cost in this case.  The result is the subcontractor seeing 48% of the cost of the project as compared to 9% in the previous example.

The above statistics are interesting for several reasons.  The first one, as stated in the article, is the fact that BIM modeling is implemented by head contractor and other associated designers; yet in some cases, the subcontractors see the benefits.  Seeing as changes in pricing are based on estimation based on previous projects, pricing benefits aren’t planned for in the budget as efficiently, and, depending on the project and head contractor, a subcontractor could see large and consistent benefits.  This means that the benefits of using BIM might not be maximized aside from time and documentation for the head contractor in that situation.  And if it is a case where head contractors see a large amount of the cost savings, they can more readily pass along the cost saving of BIM modeling. But the subcontractors may not be motivated to help improve the BIM modeling because it doesn’t help their bottom line.  For both of these reason, it makes sense why it is most common for head contractors and designers to push for improvements and BIM modeling.  However, an often overlooked requirement is that the subcontractor needs to work with the head contractor in implementing the improvements and have proper motivation to pass along the savings the see the full benefit for everyone involved with the project.

What is your opinion on BIM model implementation in regards to subcontractors and head contractors?  Are there any ways to promote a shared interest in BIM modeling?  Thanks for your time and have a good week!

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

Applying Modular Building Designs to Tall Buildings

Hello everyone.  I hope you have been doing well.  Today, I would like to talk about the recent trend of expanding modular design to new types of buildings.  Previously I wrote a blog post on the possibility of using small modular nuclear reactors to expand our energy production.(http://goo.gl/1xKK0x)  Now, there is a example of a modular design used in a 32 floor building in New York, as discussed by Fast Company Online. (http://goo.gl/lh5D93)  The are several benefits outlined in the article; and I can also see several further advantages and disadvantages as well.

The building is called the B2 building and was developed by Forest City Ratner.  It will have apartments varying in size from 450 to 950 sq ft. Everything including the kitchen appliances and bathroom are built off site and the plumbing connections are the only parts constructed on site using snap together pieces.  The assembly line combined with the accelerated schedule concept are applied to speed up construction time.  FCR claims that the total construction time for the project is 18 months, a 1/3 reduction of the normal time required for conventional construction.  They also claim that they will reduce construction cost and material waste by 70% to 90%.  Modular design has been common since World War II in buildings such as low rise schools, hospitals, and government buildings.  It is only recently that modular design has been considered for other projects.  FCR says they will dedicate 50% of the apartments to affordable housing.  The modular system will be supported by a steel braced system and a conventional foundation.  When put into place, the modular units are connected with rubber sealant.  The system is built within a 1/8 in tolerance limit – similar to what you would find in air craft engines and some areas of the car industry.  The article describes this as the start of transition to a new way of thinking about tall building design.

I see several advantages to this. The main one is the reduced cost and construction time.  With experience and time, I believe we will see the same benefits found with using prestressed modular concrete design for highway structures.  I also see potential for having your module be customizeable in the future.  Having people pay in advance for specific features and appliances from a predetermined selection can be a good way to increase funding.  However, I also see some drawbacks.  Designs need to be carefully checked in regards to meeting load requirement depending on a change of location.  The need to meet those requirements may make it more difficult apply large scale modular design to this process.  And then there is the issue of how this compares to future developments.  I previously wrote a blog post about Mass Timber design and how it is being used when sustainability is a concern. (http://goo.gl/VeDGCm)  There is always going to be competition from other methods, materials and designers.  If the number of projects it is used on is reduced, it would limit the benefits from it’s modular design on a larger scale as well.

What are your opinions on modular design?  Do you think this design method will become more common for tall buildings in the future?  Be sure follow me and share my articles if you enjoy the content.  Thanks for your time and have a good week!

The Future of Timber Design: Mass Timber

Hello everyone! I hope your week is going well.  Nothing new is happening as far as work goes.  However, my blog has 25 followers which I’m happy about. If I was more dedicated to it I’m sure I would have more lol, but I appreciate the meager following I do have none the less.  Today I wanted talk about an increasing trend in timber design – the usage of mass timber.  I recently read an article talking about a firm and some of their designs they have applied it to in this article – http://goo.gl/kp74gr.

I won’t go into detail about the projects listed in the article itself because it isn’t so much about mass timber, but instead about the companies projects.  My goal today isn’t to do a description of the companies projects and applications but rather some of the benefits listed in the article.

Sustainability – Using timber, as most people know, has the benefit of being sustainable because it is created in nature.  This allows it to be the most energy efficient in regards to production and has the lowest pre-construction carbon emissions of all the materials .  Along with that, timber will continue to absorb some carbon from the atmosphere even when part of the structure.  One of the common concerns about the movement towards mass timber is the exhaustion of the timber resources.  However, the way mass timber is created combined with replanting operations for the trees that are chopped down can help with that issue.

Allows for Increased Building Height – Currently the IBC has building height limit of about 4 stories.  These improvements introduced by mass timber can allow for buildings to be built over this height which then means that a lot of buildings that required concrete or steel in their designs before could now be built with timber if applied correctly.  More time and research will be required to allow for change in the code, but the current research and applications seem promising in regards to that.

Fire Protection – Mass Timber also has greatly improved fire protection which is a critical element in regards to the IBC as well the building height limit.  More specifically, the article notes that mass timber doesn’t burn as easily as regular timber – my guess would be due to the size and treatment in the creation process.  Also, larger members such as mass timber and regular large size timber beams form a charring around it which helps add greater fire protection.

Increased Directional Strength – Mass Timber that uses the glulam process can increase strength in one direction very efficiently which could help with the lateral loads for wind and earthquake.  These loads become increasingly critical as a building increase in height and this should help in dealing with the larger wind and earthquake loads on taller buildings.

What are your thoughts on the Mass Timber innovation?  Have any of you seen this used in design practice and, if so, what advantages/disadvantages have you seen?  Thanks for your time and have a good week!

Can the World’s Tallest Building Be Built in 90 Days?

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Hello everyone, I hope y’all are doing well.  Today, I want to talk about an article I found a while back.  In the article, the construction company building the next building slated to be the tallest building world claims that they will do it by the end of 2013.

At first, I thought this was not possible at all.  However, the company, Broad Sustainable Building, has previously built a 30 story apartment building in 15 days.  Apparently, the plan will be to prefabricate as much as they can off site in the 4 months before on site construction starts.  Since they just got their permit this June that means they should be done with that by the end of September.  This leaves them 3 months to do the on site construction if they want to finish in 2013.  According the article, the plan is to build five stories of the building each day.  Along with the quick construction time, the skyscraper will only cost $628 million; half the cost of Burj Khalifa.

However, as cool as this sounds, I have some skepticism about how this can be done and so does the author.  A 30 story apartment building has far fewer critical design issues than 220 story skyscraper.  In the article, Head of Structures for WSP Middle East, Bart Leclercq, believes that they will run into issues with the required use of on site concrete work which provides the extra stiffness needed.   In order to safely construct the building, adequate curing times are needed which would be hard to manage with the fast pace of construction.  The other concern that crossed my mind even though it wasn’t stated in the article is this – what will be done about inspections and oversight?  If a building is being erected this quickly, a lot of oversight and coordination will be required and I could see a lot of mistakes being made as rushed as the process would be.  What is your opinion on this project?  Do you think that this building schedule is attainable?  What about safety and risk in regards to the building schedule?  Thanks for reading and have a good weekend.

The Philadelphia Building Collapse in Regards to Responsibility in Building Design and Construction

Hello everyone.  Sorry I have been away for so long.  I haven’t felt particularly inspired to write blog posts lately, which is not a good excuse, but I am finally getting back around to writing some now.  Nothing has really changed in my professional career or school activities.  I am still looking for work and planning on taking the comprehensive exam to graduate.  On a fun side note, I have discovered that I lost some important notes over the years so I need to figure out what to do about that.  Other than that, everything is going smoothly.  Today, I would like to discuss an incident in which a building collapsed and causes several deaths and injuries in Philadelphia.

First of all, let’s start with a recap of what happened.  The construction worker, Sean Benschop, was demolishing a four story building and part of the structure collapsed onto the Salvation Army next door.  He will be charged with one count of risking a catastrophe, six counts of involuntary manslaughter, along with counts of recklessly endangering another person.  Benschop turned himself and this his attorney made this statement, “He and his family are extremely sympathetic and remorseful with respect to what happened. This was an accident. Mr. Benschop is not responsible and we believe that in time the facts will show that he is not responsible and the responsible party will be held accountable.”  Philly.com reports that there was marijuana and pain killers in Benschop’s blood two hours after the accident.  His attorney claims that Benschop was fully able to operate the backhoe in a safe manner.  In response to this incident, the city of Philadelphia has inspected hundreds of demolition sites and is planning to implement changes in building demolition regulations.

This incident illustrates an interesting topic that any engineer with a PE License should understand, the designer is held responsible when his or her structure fails.  And apparently, based on this specific incident, a construction worker can be held accountable if there are deaths involved.  However, I think there are important questions that need to be asked.  The first one is this: What is the building designers role in this?  Was there an on-site structural engineer that should have noticed the danger that structure next to it could be damaged?  The second is this: What is the construction managers role?  Should he be held responsible for allowing an operator to work in an unsafe manner considering the pain killers and marijuana is his system?  Would the construction manager be liable for the safety zone and structural concerns on site as well?  And finally: Was the construction worker ordered to do the work?  Is the work environment such that he can voice concerns for the safety conditions if needed?  It is my opinion that not enough investigation has been done into the operation of the construction project at the time of the accident.  I don’t think there will be an accurate picture of who is responsible and what actually happened in regards to the decision process if that isn’t done.  What is your opinion?  Who do you think is more responsible for the pedestrians deaths and why?  Thank you for reading and have a good week.

Source:  “Construction Worker In Custody For Phila. Building Collapse”, National Public Radio, June 8, 2013, http://tinyurl.com/mn6vrqp

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