Wednesday, April 25, 2018

Concrete block to make ships, boats, barges and more

This material is based upon work supported by the National Science Foundation under Grant No. 1660075 ("Topological interlocking manufactured concrete block").  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author, and do not necessarily reflect the views of the National Science Foundation.

I have written previously about using masonry to build a submarine, here and there.  A masonry submarine sounds a little far-fetched, but -as I tried to show- it's really not.  A masonry submarine seems like a practical idea if you really think about it.



Something less far-fetched than a masonry submarine is the idea of a masonry ship, or boat, or barge.  I've written previously on a national competition that occurs in the US between various engineering schools to design, make and race concrete canoes. The ASCE (American Society of Civil Engineers) sponsors the annual Concrete Canoe National Competition as an engaging, fun and interesting exercise for engineering students to become involved in the design and use of concrete as a material to be used in boats, as canoes.  This is an idea whose use is well established and known, although the general public may not be fully aware of this.



The idea for concrete boats has been around for over 150 years now.  The oldest known ferrocement boat was a dinghy built by Joseph-Louis Lambot in Southern France in 1848.  In the 1890's concrete ships, boats and barges were designed and built by an Italian, Carlo Gabellini.  Concrete boats were practically common during both World Wars.  They were made partly in response to the war's demand for steel, because a concrete boat does not have a steel hull.



Ferrocement is simply steel reinforced concrete.  A metal grid is located in the center of the concrete thickness, providing tensile strength to the concrete matrix.  While concrete has a high compressive strength, it has virtually no tensile strength, so metal reinforcement is required to make a tougher material (resistant to crack propagation).



The difficulty with a ferrocement boat is that eventually micro-cracks will form in the concrete matrix.  Water will migrate and travel through these cracks until it reaches the metal grid located within the concrete.  Of course the metal will then rust: it expands as it rusts, widening the crack, allowing more water in, creating more rust, further widening the cracks, etc., until the boat's hull does not maintain structural integrity.  Nonetheless, concrete ships are known to have lasted over a century; such as the Violette built in 1917 and now serving as a boating clubhouse on the Medway River in England.  There are also concrete barges on the Erie Canal in New York State, which were also built around 1917.



I had been thinking about concrete ships, boats, barges, submarines and similar applications for several years.  In the course of doing work which is funded by the National Science Foundation (NSF Award #1660075, "Topological interlocking manufactured concrete block") I was made aware of another start-up company, also funded by NSF, called "Neuvokas." Neuvokas makes a reinforcement bar ('rebar') by melting basalt, a high-density rock common around the planet, and drawing it into fibers (like fiberglass) and then epoxying those fibers together into a rod.  The resulting material is very lightweight, has a higher tensile strength than steel, and (very importantly) it never rusts.  I have been using gatorbar in my masonry system, to build arches and domes and even flying buttresses.  It works very well, is cost competitive with steel rebar, and again: does not rust. Below is a picture of one of my arches, being made with gatorbar.  Further below is a schematic of these same block making the hull of a ship (FIG. 16), and rebar configuration (FIG. 17).  The corrugations created by the herringbone block pattern provide additional flexural rigidity to the hull, making it stronger.





It occurred to me that the masonry system my company is developing would be suitable for making the hull of a concrete ship. Simply take a masonry arch, and turn it upside-down, and you have the hull of a ship.  In order to provide additional strength to the hull, a series of bulkheads are located across the beam of the hull, in which rebar is located, to provide tensile strength across the hull.  Compressive strength is also created by these bulkheads.  The bulkheads are made by simply using regular, rectangular concrete block. In one embodiment (shown below) the design uses a traditional 3 centered arch, but inverted; this should make for a more stable boat than a simple cylinder or inverted barrel vault. A waterproof coating can be applied to both exterior and interior surfaces.  The vessel is also divided into a series of watertight compartments.  Flotation foam can also be included into the compartments.  All of these features create redundant safety factors into a ship made of concrete block.




By using a material such as gatorbar, reinforcement can be provided which will never rust.  This creates an ideal ship hull.  A ship's hull can be made very inexpensively, it can be made virtually any size, it will never rust, it will never grow barnacles, it never needs to be painted, it would never need drydock repairs.  After doing some research, I realized that no one else had really done this sort of work, or idea, or boat: a vessel whose hull is made from manufactured concrete block.  By using the arch block design (discussed here on this blog) this design also takes advantage of the anisotropic nature of manufactured concrete block.  That is, manufactured block has a high-strength axis, and this high-strength axis is always oriented radially outward, imparting its maximum strength qualities into the ship. The bulkheads simply use regular rectangular concrete block, with vertical and horizontal rebar (gatorbar).





A new US patent application was recently filed by my company, simply entitled "Floating base." This patent application includes students from the Senior Project class I taught at Alfred University's Inamori School of Engineering, namely: Benjamin Cleaver, Matthew Freitag, Ryan Miller, Charles ('Addison') Heulitt; under the direction of  their professor Dr. Ehsan Ghotbi, and my employee Stephen Bonan (good job guys!). It appears as though this field of invention is wide open, that none have really tried what my company is attempting here.  It will take us some time to prove this idea by actually building and testing a large concrete ship, but this appears very practical, affordable, and looks as though it would create a ship superior to conventional steel-hulled ships or wooden ships in terms of cost, maintenance, life-cycle, and so on.  Shown below is an artist's conception of our concrete block hulled ship, used as a platform for residential housing.  The future looks buoyant for ships made from concrete block.




Tuesday, December 5, 2017

How it all began

I have been working on using manufactured concrete block to make roofs, including domes, arches, spheres, flying buttresses and more, for around 27 years now.  Today I'm taking a look back at how this all began.  I am prompted to do this by some old photographs which a friend (Paul Sofinski) recently shared on facebook from many years ago, when I was studying ceramic engineering and ceramic art at Alfred University's New York State College of Ceramics.

As a child I was fortunate to live in Europe, where my father was on sabbatical as a professor of European history.  My siblings and I were dragged into many of the great cathedrals of Europe, where I would stare in awe at these wonders of masonry.  A seed had been planted in my young mind.

I began doing pottery in high school.  I went to Guilderland Central High School in Guilderland, New York.  I was fortunate enough to have Mr. Paul Krauss as a ceramic art teacher.  Under his tutelage I began working on the potter's wheel and spent a few years after high school making and selling my work. I attended the University at Albany in the early 1980's, where I studied geology and in my spare time made and sold pottery at the university's campus center.

Some years later I decided to attend Alfred University.  I initially went there to study ceramic engineering, but once I saw their art facilities, I decided to pursue art also.  I was looking for a more challenging aspect of art to investigate, so my work became large in scale.

Here are some pictures of me and this early student work.  I would use a forklift to move these pots around, to get them in and out of the kiln, etc.


This became interesting from an engineering perspective.  These pots at first were anthropomorphic, being human in scale and proportion; having a foot, a shoulder, a neck, and so on.  This quickly transformed into their becoming architectural, and soon I was contemplating the notion of a ceramic house.  I combined my ceramic art and ceramic engineering studies at Alfred, and obtained a custom degree in Masonry Science.

I researched ceramic houses, and investigated the work of Nader Khalili, Paolo Soleri, Bucky Fuller, and others.  Nobody was doing what I was thinking about.  My approach seemed obvious, self-evident and simple.  I wanted to use common concrete block technology (usually called a "cinder block") to make roofs, in the form of arches and domes. I sought to combine the high efficiency and very low cost of concrete block automated production with the high compressive strength and design flexibility which symmetry and geometry make possible. I was shocked to learn that this had never been really attempted.  It seemed like an interesting and unique opportunity, so I pursued it. 


It takes a naive young person to try something new!  I was that sort (still am, to a degree).  I encountered the extremely conservative construction industry, and the even more conservative practice of masonry.  Over the years that followed, I have worked and produced designs, buildings, molds, blocks, patents, and done my best to try and demonstrate my ideas within my limited economic means (it is expensive to try and change a global industry by one's self).  My work has gained some recognition and has garnered interest nationally and globally.  Currently I am completing my third funded award from the National Science Foundation, wherein I am seeking to gain a positive evaluation report from the International Code Council - Evaluation Services.  This will allow this technology to be sold as a product globally. It all began with an art student making big pots.  Now cut your hair and get a real job!


  

Wednesday, November 8, 2017

Making a small concrete block masonry building

This material is based upon work supported by the National Science Foundation under Grant No. 1660075 ("Topological interlocking manufactured concrete block").  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author, and do not necessarily reflect the views of the National Science Foundation.

Today I'm taking a look at the construction of a small building assembled from manufactured concrete block.  This particular building was made to serve as a kiln room.  A kiln is a high temperature oven or furnace used to heat (fire) ceramic material.  Kilns may also be used to melt metal, or glass, or for any heat-treatment of materials, such as drying green wood.

This building has a footprint of around 14 feet by 12 feet, or around 170 square feet.  There is a trend today toward "tiny houses" where people are attempting to live in such small spaces.  Personally, I don't mind living in a small house (under 1,000 feet is OK) but I would not care to live in such a small space as this: it is appropriate for a shed, or a safe room, or even a kiln room.

A "safe room" is an appropriate use for a building this size.  A safe room like this would be appropriate to survive a tornado, or hurricane or wildfire.  The need for an affordable, high-strength, fire-proof safe room has been brought into sharp focus over the past few months, with the arrival of hurricanes Harvey, Irma and Maria; and also with the devastating wildfires in California and across the American West.  A building such as the one shown here would allow people to survive any of these disasters, providing safe refuge in the face of any of these natural disasters.  Many residents of Texas, Louisiana, Florida, Puerto Rico, US Virgin Islands, and California would have benefited from one of these structures during the hurricanes and wildfires which impacted these areas.  A structure such as this provides an affordable solution to these natural disasters, and gives people a safe place to survive these devastating type of events.

Following are some photographs showing the construction of this building.  The vertical walls were made with standard 8 inch x 8 inch x 16 inch concrete blocks, or "cinder blocks" as they are commonly known.  The side walls of this building include blocks which are oriented with their long dimension oriented at a right angle to the wall, creating a series of vertical buttresses, or pilasters for additional strength and reinforcement.  These blocks have hollow core holes which were subsequently poured with grout and also contained a series of vertical rebar for additional reinforcement.


Here is the building site before construction began.


Construction has begun, a few hours into it.


Vertical walls almost completed, this took 2 days to build.

There were 450 regular 8 inch x 8 inch x 16 inch block used to make all of the vertical walls.  These block cost $1.20 each.  There were 30 8 ft. pieces of rebar used in the hollow vertical cores of the walls, which were poured with grout.  I used "gatorbar" rebar, made by Neuvokas Company.  This rebar is made from basalt, which has a very high tensile strength and will never rust20 foot long pieces of this rebar cost around $5.50.  The grout cost around $30 for the entire structure.  Mortar for the entire structure cost around $45.00.  The material cost of these vertical walls (including block, mortar, rebar and grout) was around $700.


This shows wooden forms used to make arches between the vertical buttresses or pilasters.


Here are wooden forms used to make a concrete skewback, from which the masonry arch roof is built, or 'sprung.'  


This shows the arch assembly as it begins.  Note the use of 'gatorbar' rebar used to help create the arch.  This block is described in more detail here.


Here is the masonry arch being constructed.


This shows threaded anchor bolts (3/8") which were used to attach a wooden covering to the roof.


This is the 3/8" anchor bolt, which is inserted into the mortar beds between blocks of the arch.


Here is the building with a completed masonry arch.  This could have been made waterproof with any number of techniques, including waterproof paint, rubber roofing, etc.  I try to use the most common construction practices, methods and materials: so I used a wooden surface, covered with tarpaper and then finally covered with shingles.  Any of these methods will work.


Here is the wooden roof surface, covered with tarpaper.  Note the stainless steel chimney for the kiln in the back.


Here is the shingled building, more or less complete.  I will still install a door, and I may paint the building with a waterproof masonry paint, such as (for example) Drylok(TM).





This building represents a simple, high-performance, inexpensive approach to providing a very safe structure capable of withstanding wildfires, tornadoes, hurricanes, and other extreme weather events.  The cost of materials for the vertical walls was around $700.  The cost of the masonry arched roof was $644 in block, around $70 in mortar, and $77 in rebar for a total material cost of $791.  The total material cost of this building was $1,491.  This material cost does not include labor, and labor costs vary widely.  This was built by two masons working for 5 days, 8 hours each day.  By comparison, a smaller shed made of flimsy wood sheathing which is much smaller (8 ft. x 12 ft. vs. 12 ft. x 14 ft.) costs $2,199.  This wooden shed will burn, rot, suffer from insects, and is not nearly as strong: it would not survive a direct encounter with a hurricane or tornado.  There is really no comparison!  The wood shed costs $22.90 per square foot, the concrete building shown here costs $8.77 per square foot.

Upon completion of work funded by the National Science Foundation (Phase II, Small Business Innovation Research, SBIR) within the next 2 years, this technology should be accepted into the International Building Code and is expected to be available for sale internationally.  This small building is just another example of what this innovative masonry technology makes possible.  Better, stronger, safer buildings at a lower cost. 



Friday, August 18, 2017

Building Another Masonry Prototype

This material is based upon work supported by the National Science Foundation under Grant No. 1547958.  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author, and do not necessarily reflect the views of the National Science Foundation.

One year ago (late summer, 2016) I began working on a masonry prototype which would use the novel topological interlocking manufactured concrete arch block, described and discussed here.

I had been teaching a Senior Project engineering class at Alfred University's Inamori School of Engineering, and asked my students to help design this structure.  The students I had the pleasure of teaching include undergraduate students Pavel Boyuk, Patrick Byrne, Wanrui He, Nolan Jessop, Sanket Patel, Nick Roberts and Alex Wessner; under their professor Dr. Ehsan Ghotbi, and also graduate student Martin Monk under his professor Dr. William Carty.

Here are some of the drawings these students did for this structure.  The actual design was changed somewhat from these drawings to what was actually built. These changes include switching from a round profile to a catenary profile on both the main arch for the roof, and also on the flying buttresses which are located on either side of the building.  I also went from seven buttresses per side (as per the students' drawings) to six buttresses.  Finally, I also included two Gothic windows on one side of the main arch.



This building was erected on my own personal property in Alfred, New York. Site preparation began with felling several trees and clearing the logs from the site.  I'll just let the pictures tell the rest of the story, beginning with the building site as it was.





This is the retaining wall, built around the site.


Retaining wall behind, foundation (footer) in the front.


Lots of gravel for proper drainage, very important.




Vertical walls erected.


Those are the flying buttress foundations, on the left.


The slack chain hung in the picture below was used to create the catenary form for the flying buttress.  This is much stronger than a simple, round form.  This shape was traced onto a piece of plywood, the plywood was cut, flipped upside-down, and used as a guide form.



This shows my method for assembling the flying buttresses.  These went up quickly, each flying buttress took around one hour for me to assemble.


This shows the scaffolding, made from the trees which I cut down from this same site.


Here is a concrete block delivery truck, placing block on the scaffolding.  The scaffolding held around 50 tons!


Here is how I made the catenary form for the roof.  I traced the curve made from the slack hanging rope onto wood, and cut out that shape.  I then flipped this shape upside down, and used it as a guide to assemble the roof.




Gothic windows on the side of the structure.





I covered the arch in wood, so that I could apply conventional tarpaper and shingles.



Here is the inside of the structure.  It's an interesting space inside, very roomy.
Here is a concrete 'apron' for the beginning of the driveway.  This will have a pattern stamped concrete driveway, which is about to be made.
These trenches for drainage are 4 feet deep, and hook up to a large drainage pipe.




Here I am beginning to apply architectural shingles.  This building is almost complete.





This was an exciting and fun project.  Much was learned, this first prototype is somewhat crude, since it was a first attempt.  The arch span is over 25 feet, and the depth of the arch is over 30 feet.  The reader should also note that while I was building this, I simultaneously wrote and filed a patent, wrote a Phase II Proposal for the National Science Foundation (successfully, it was funded) and several other large tasks at the same time.  This building actually went up very quickly.  They will only get better!