## Wednesday, March 31, 2010

### From a simp to a dimp

Is it possible to create a triangular block with more of an interlock than the ‘simp’ (single inverse mirror plane) design we looked at yesterday? The answer is yes, and this is done by using more of the symmetry elements to create a shape with a more articulated design.

If we look at one of the abutting faces to these interlocking blocks, the simp has an inverse mirror plane located midway between the two corners of the outside face of the block. This first inverse mirror plane is oriented in a radial direction: it goes through the center of the sphere which the blocks assemble into.

If we provide yet another inverse mirror plane, oriented at 90 degrees to the first inverse mirror plane, then the second mirror plane is not radial but tangential to the assembled sphere. This second inverse mirror plane imposes a higher symmetry to the block shape. This arrangement provides many benefits to the interlocking block shape. Since each of the abutting faces of each block now involves two inverse mirror planes, I refer to this arrangement as a “DIMP” or Double Inverse Mirror Plane.

The mold separation line for a ‘dimp’ block is not a simple flat plane –like it is with a simp- but ‘jogs’ up three times as we go around the block. The higher symmetry dictates this sort of mold separation.

As dimp blocks are assembled, they create a much more solid and substantial interlock than with a simp. They slide and lock into position with multiple contact and guiding surfaces.

Each of these surfaces is a conjugate shear plane, as discussed two articles ago on this blog. This means that an assembled structure is free to deform under applied forces: it can strain under stress without breaking.

Another strong advantage to the dimp design is that the extra inverse mirror plane creates symmetry which allows a tensile element (e.g.: cable, wire, etc.) to be woven into the sphere or dome as the blocks are assembled. The straight line-of-sight on the abutting edges is a tangential pathway for a tension element which is woven into the structure as it is assembled. This means that the structure does not have to rely on gravity alone to hold the structure together; there can also be an element of tension that binds blocks together by a cable, or wire or other tension element. The location of this wire is shown in the drawing below, and is labeled 660.

This geometry is in many ways fundamental and basic to the problem of creating an interlock without a draft, or negative angle or undercut. I felt as though I had uncovered something that already existed, rather than actually inventing something.
There are a number of distinct advantages to both the simp and dimp blocks, depending on their use and also depending on how they are made. We’ll look at some of these differences tomorrow.  I'll also try to provide some photographs of the dimp in use.

## Tuesday, March 30, 2010

### When a simp is not so simple

We’re back looking at the problem of creating an interlocking triangular block which can release from a simple two-piece mold, without a draft angle, or undercut. The diamond-shaped key discussed in the last post allows for the blocks to be assembled without an undercut, but the half-diamond recesses create a negative angle, or draft, or undercut: in terms of releasing from a mold. These blocks would be stuck in a mold, and couldn’t be pulled out.

The answer to this problem was realized by playing with symmetry. Geometers (yes, geometer: one who does geometry) use various symmetry elements to describe the order present in a system. In particular, I began using the inverse mirror plane. This type of symmetry is an imaginary plane which bisects a given object. The inverse mirror plane acts like a mirror in that it reflects the arrangement on one side of the mirror: except that it flips it upside down, or inverts it. If something is ‘sticking out’ on one side of the plane, it will be ‘sticking in’ on the other side of the plane.  Below is a hexagonal block with these features.

I realized that if I located an inverse mirror plane at the midpoint of the abutting edges of a block, I could put half of the diamond-shaped key on one side of this plane, and the other half would be its inverse, or opposite, or keyway. I called this design the “SIMP” or Single Inverse Mirror Plane.

While the triangular block is made like a wedge, or bevel, or tapered block; the half-diamond key is kept at 90 degrees to the faces. In other words, it does not conform to the wedge, or taper, or bevel of the block. This aspect gives the key and keyway a more substantial interlock. The half-diamond shaped key is itself a wedge, displaced counter (opposite to) the wedge of the block itself.  Below is a pentagonal 'simp' block.

This arrangement of symmetry elements allows the interlocking block to be made on a simple two-piece mold. This was a “game-changer” in terms of providing an interlocking block design based on a unit shape that could be mass-produced with common equipment.  Below you can see how these blocks assemble with the interlocking feature.

Can this interlocking feature be made any better? Is it possible to have any more interlock without creating an undercut in terms of mold release? It doesn’t seem possible, but it is. We’ll look at that tomorrow.

## Sunday, March 28, 2010

### Diamond Key

The challenge of this block design was to make an interlocking block that could release from a simple mold. An interlock sticks the block together, but this interlock can’t get stuck in a mold. This apparent contradiction was overcome by using elements of symmetry in the design.

This design evolved over different versions, and I continue to play around with different configurations. After designing the simple, tapered triangular block I looked at a more efficient way to connect the blocks at their abutting faces.

I decided on an independent diamond-shaped key, which was sunk halfway into the abutting edges of two adjacent blocks. The triangular blocks are made with half-diamond shaped recesses (keyways) on each of their three abutting faces. The diamond-shaped keys are made with an obtuse angle of 120 degrees and an acute angle of 60 degrees.

Blocks are assembled by first stacking with triangular tips pointing up, and placing keys into the keyways. Then blocks are inserted between the first course, with tips pointing down. Blocks are able to assemble without any undercut. For example, if the independent key were shaped like a square, there would be an undercut (or draft, negative angle) and the blocks couldn’t be assembled. This illustration shows it better than words can describe it. If you click on the picture you can see it better.
There are a couple of problems with this system. First, the independent keys require that a relatively large number of them be made. It would be better if the key and keyway were an integrated part of the block. Second –and more critical- is the fact that these blocks don’t readily release from a simple two-piece mold. This means that these blocks couldn’t readily be made on regular block machine.

The system works pretty well though. Years ago I made a prototype out of concrete, using hinged plywood molds. The blocks were used to build a dome dog house for my dog Maximillian. This early prototype dome now sits atop a cupola on a much larger dome at my property in Alfred NY.

How could an interlocking block be made on a block machine? The diamond-shaped key & keyway system pointed the direction toward a better solution, and we’ll look at that tomorrow.

## Friday, March 26, 2010

### How rocks break under pressure: Conjugate Shearing

Before I get back into undercuts, mold release, and assembly of shapes; first we’ll take a look at conjugate shear fractures. This is an important aspect of this masonry system, since it uses this failure mechanism to its advantage.

It’s important to know how rock (or concrete, or ceramics) breaks. Concrete is strong if it is squeezed together, under compression. A high compressive strength is central to the masonry design I’ve been working on. The idea is to keep the assembled structure under compression, to take advantage of this high compressive strength.

When concrete is squeezed together (compressed) until it breaks, it eventually breaks at angles to the applied force. These fracture angles are at around 60 degrees to the applied force. Sets of fractures occur which allow for displacement. This is known as conjugate shearing, the mode of failure is known as conjugate shear fractures. Conjugate shear fractures are common in geology, and are well documented.

To give an example of conjugate shearing, if you take some chilled butter, and press into it with the flat side of a knife, the butter will shear away from the applied force: conjugate shearing.

Triangular blocks are inherently disposed to conjugate shearing without suffering brittle failure. In other words, a control joint (one that allows for movement) allows blocks to move the way they want to move without breaking. Stress is relieved by strain. Gravity acts as the restoring force, returning a structure to its original position.

It just so happens that every face of the interlocking block system I’ve developed is a conjugate shear plane. The system will remain locked together while allowing some movement (strain) to relieve any applied force (stress) that may occur in extreme loading conditions, such as an earthquake, tornado, hurricane, etc. This masonry system is very tough, meaning that it is resistant to crack propagation.

With this short discussion of conjugate shearing, it should help the reader to more fully grasp the beneficial aspects of the articulated interlocking block, which I’ll begin to describe tomorrow.

## Thursday, March 25, 2010

### When Fuller means Less: the weight is over.

I wanted to design a masonry unit (block or brick) which could assemble into an entire structure, including a roof. A sphere seemed like an obvious solution, part of a sphere could be used as a dome.

Work by others such as R. Buckminster Fuller and Barnes Wallis had helped to pave the way. “Bucky” was an odd individual who had some real insight and developed some interesting ideas. He applied himself to doing the most with the least: to enclose the greatest possible volume with the least possible amount of material. This eventually led to what he called a “geodesic.” This sort of geometry has been known since the ancient greeks. I find the Roman Dodecahedron pretty fascinating, their use is still a mystery.

Bucky Fuller used the weight of a structure as a criterion for evaluation. To his way of thinking, if a structure weighed “too much” it was no good. This somewhat arbitrary criterion excluded using inherently heavy masonry as a construction material. For Bucky, structures should be made using the mass-producable methods developed by the US during the war effort of the second world war. Houses should be made of materials like aluminum, mass produced in factories, and we should be able to drop them on site with helicopters. Airstream styling for a brave new world. Look at his ‘dymaxion’ car and house, you get the feel for it.

It turns out that the ‘geodesic’ template lends itself very well to masonry construction. I worked on the specific case of a truncated icosahedron. This is the geometry of a common soccer ball (football for non-Americans) where the black patches are pentagons and the white patches are hexagons. By subdividing these hexagons and pentagons into their respective constituent triangles, we begin to get close to manageable unit shapes.

To make a larger structure, a given unit triangle is simply subdivided into four smaller triangles. By doing this, the unit shape for a large structure can be kept small and manageable for construction purposes.

In considering assembly, I thought it would be advantageous if the blocks could interconnect, or lock together by some sort of retaining system. At first I had a simple hole located on the side of each block, into which a pin could be inserted, connecting two adjacent blocks.

In order to economically mass-produce these unit shapes, they would have to release from a two-piece mold (the sort used by the block industry) without any draft, or undercut, or negative angle. A simple hole to connect blocks -like I had first thought of- creates an undercut. These holes would have to be drilled after the block was made. This was expensive, time-consuming and impractical.
Another obstacle to the idea of interconnecting blocks was that they had to assemble without any undercut. An interlocking feature –by definition, almost- creates an undercut, or draft, or negative angle. An interlock can prevent the blocks from being assembled. How could this be done? That’s for tomorrow.

## Wednesday, March 24, 2010

### A Ceramic House?

I began to look at a new masonry design in the early 1990's. I had been throwing very large ceramic pots, and they were an interesting challenge from an engineering standpoint. They became quite architectural, and I began to ponder the notion of a ceramic house.

After doing some research, I realized that others had been investigating ceramic houses. In particular was an Iranian architect located in southern California, Nader Khalili. He was doing some very cool monolithic ceramic houses which were fired on-site, with large burners mounted in doorways, windows, etc. While this seemed pretty cool, and while his work was a real joy to look at, it struck me as impractical. Sadly, Mr. Khalili passed away in 2008.

It occurred to me that it would be more practical to break the house into component parts which could then be assembled. This was masonry. Thus began my venture into the wonderful world of masonry.

To keep this doable and relatively easy, I realized that the number of different shapes should be kept at a minimum. They should also be produce-able on a simple mold, should bear any load properly, and should be small enough to be handled by a single person.

## Tuesday, March 23, 2010

### Manufacturing Block

State-of-the-art block manufacturing has evolved to a very high state of efficiency over the years.

Here in the US, two of the largest and better known block machine manufacturers are Besser Block and Columbia. Both of these companies have a global reach, and influence block manufacturing on a large scale.

If you've never seen a block machine in action, it's really something to behold. So much power, efficiency and speed both instantly and endlessly putting out block. The level of automation in a modern plant is amazing; the block are practically never touched by hand.

Here is a decent video from an Italian machine and plant manufacturer, Rosacometta:

I hope I've set the stage for a basic understanding of modern masonry. Tomorrow I'll start describing some of my own technology.

## Monday, March 22, 2010

### Cinder Blocks: a cinderella story

What is a cinder block? It conjures an image: 8 inch by 8 inch by 16 inch rectangular cube, with two or three core holes. Grey and dull, solid and regular, straight walls and square corners: as American as WalMart.

Actual cinder blocks are pretty cool. You can’t get them any more. They used to be made from the cinders which were a waste product of burning coal. Coal combustion is now done much more efficiently, and doesn’t create large cinders but a very fine fly ash. No more cinders, no more cinder blocks.

Around 1910 coal cumbustion produced cinders, and few places burned more coal than Pittsburgh, Pennsylvania. A brick mason from Pittsburgh named Francis Straub realized the potential of this large volume waste product, and experimented with cinders and cement. This led to the discovery of material mix designs for cinder block in 1913.

Cinder blocks are lightweight, insulate, and nails can be driven into them. Mr. Straub had many challengers to his technology, and fought several patent infringement cases on his invention. The crux of the decision on his case was that if you could drive a nail into a block, it was a cinder block: it was his patent, and nobody else could make block like that.

Mr. Straub would show up at competitors he suspected of infringing on his patent, and try to drive a nail into one of their blocks. If he could drive a nail, he would collect royalties or shut them down, or both.

Around 1936 the United States made a decision to streamline construction and manufacturing by making all construction materials based on a modular coordination of design. It was decided to base all construction materials on a 4 inch cube volumetric grid, so that all materials were designed to fit within this grid; everything from sheets of plywood to 2”x4”s, to windows and doors. The block industry settled on the 8’x8”x16” design which we’re so familiar with today.

Eventually coal combustion became more efficient, and cinder blocks were no longer made. The term stuck though, so today people still refer to concrete blocks as cinder blocks. Today the fly ash from coal combustion is used as a pozzolanic material in concrete, creating a higher strength concrete. They are more dense and you can’t drive a nail into them.

“Cinder block” is practically a cultural icon, it is so ubiquitous and familiar. There are musicians calling themselves ‘cinder block’, and certain crude urban interpretations have been applied to the term. All thanks to Francis Straub from Pittsburgh, circa 1913.

## Friday, March 19, 2010

### DNA of Cement

Cement seems like pretty basic stuff. It’s dusty and dirty, you mix it with sand and rock, add water and get concrete. Yes, it seems like pretty basic stuff.

For anyone who has studied cement in depth, it has remained an elusive material which has defied any definitive classification. Is it a crystal, or is it amorphous? Is it like quartz (crytalline) or is it like glass (amorphous)? And –more to the point- why should we care?

Cement is the most widely used construction material in the world. We produce 1.25 billion tons of this stuff every year. The strength of everything we make with cement and concrete relies on good quality cement. Just as important (if not more so) is the fact that cement manufacture creates a lot of CO2. Cement manufacture is one of the major contributors to greenhouse gas production, which climate scientists tell us is warming our planet. A better understanding of cement structure could provide a path toward reducing greenhouse gas generation.

Recently scientists at MIT have “decoded” the “DNA” or fundamental structure of hydrated cement. It is structured very much like a crystalline lattice, with long rows of silica tetrahedra sandwiched between layers of calcium oxide, like stacks of oranges at the grocery store, almost perfectly stacked in an ordered crystalline system.

The structure of cement has long been known to be very similar to the rare mineral tobermorite, which has these long connected chains of silica tertrahedra between calcium oxide. However, recent research by MIT scientists has shown that there are tiny gaps or flaws between the silica tetrahedra and the calcium oxide; these gaps or flaws (or interstitial sites) become occupied by water molecules upon addition of water to cement powder. Thus hydrated cement is something more like an amorphous (non-regularly repeating) structure of glass than it is like an ordered crystal.

The water forms bonds between layers of silica and CaO, helping to give hydrated cement its strength. There is some flexibility between these bonds, so that cement is less likely to suffer brittle cracking, as with a pure crystal. There is some ability for cement to move under applied stress –or strain- thus relieving the applied stress without suffering brittle failure (stress is an applied force; strain is movement under stress).

This insight into the atomic scale structure of hydrated cement was gained in September 2009. It has provided a fertile area for ongoing research and development. The hope of this new insight is that it might lead to higher strength cements (and the resulting concretes) and that ideally it may lead to an alternative chemical path for cement production which could greatly reduce the production of greenhouse gases.

Sidetracked today by this interesting scientific development, but next time we’ll look at the early history of cinder block and concrete block development.

## Thursday, March 18, 2010

### Portland Cement

Cement is often confused with concrete. Cement is the glue that holds the other concrete ingredients together (sand, aggregate and rock). Cement is the world’s most widely used construction material, with around 1.25 billion tons produced each year.

Ancient civilizations sought to bind stone together into a solid mass. Assyrians, Babylonians and other civilizations used mud for this purpose. Egyptians began to use lime and gypsum to improve their mortar to a material more durable than simple clay. Romans developed cement to a much higher degree, by including volcanic ash known as Pozzolanic material (named after the town of Puozoli, at the foot of Mt. Vesuvius). This material was used in Roman concrete, or “Opus Caementicium.” Pozzolonic material acts as a cement in the presence of cement. It is basically just ash, and does not work as a cement by itself.

Romans developed cement to a high state, as described by Vitruvius, around 25 BC in his work “Ten Books of Architecture.” With the fall of the Roman Empire, the art of cement making and use was lost. The key feature of Roman cement is that it was hydraulic cement, and would cure or set underwater.

Hydraulic cement was not rediscovered until late in the eighteenth century, when the scientific method led to its rediscovery, as discussed in this article. “Repeated structural failure of the Eddystone Lighthouse off the coast of Cornwall, England, led John Smeaton, a British engineer, to conduct experiments with mortars in both fresh and salt water. In 1756, these tests led to the discovery that cement made from limestone containing a considerable proportion of clay would harden under water.
Making use of this discovery, he rebuilt the Eddystone Lighthouse in 1759. It stood for 126 years before replacement was necessary.

Other men experimenting in the field of cement during the period from 1756 to 1830 include L. J. Vicat and Lesage in France and Joseph Parker and James Frost in England.

Before portland cement was discovered and for some years after its discovery, large quantities of natural cement were used. Natural cement was produced by burning a naturally occurring mixture of lime and clay. Because the ingredients of natural cement were mixed by nature, its properties varied as widely as the natural resources from which it was made.

In 1824, Joseph Aspdin, a bricklayer and mason in Leeds, England, took out a patent on a hydraulic cement that he called portland cement because its color resembled the stone quarried on the Isle of Portland off the British coast. Aspdin's method involved the careful proportioning of limestone and clay, pulverizing them, and burning the mixture into clinker, which was then ground into finished cement.
Portland cement today, as in Aspdin's day, is a predetermined and carefully proportioned chemical combination of calcium, silicon, iron, and aluminum.”

Portland Cement is widely used in construction today. Tomorrow we’ll look at cinder blocks and concrete blocks, and what the difference is between them.

## Wednesday, March 17, 2010

### St Patrick, Mason

(re-posting on this special day!)

Mediterranean architecture had a long history of masonry construction at the advent of Christianity as a religion. Typical Mediterranean masonry architecture included domed roofs, arches and thick stone walls.

With the gradual collapse of the Roman Empire and the spread of Christianity, evangelists brought their masonry construction techniques (as well as scripture) to northern Europe. Initially these construction techniques dominated as Romanesque architecture. This architectural style is characterized by round arches, thick walls, and generally stolid (unmovable, dull) and squat configurations; typically described as "over-engineered" and using a surplus of material, or "more than is needed."

Romanesque architecture endured and flourished across northern Europe for centuries. The existence of this architecture today is a testament to its high strength and robust design.

One of the unique evangelists who spread the gospel was St. Patrick (circa 420's AD) who brought Christianity to Ireland. He is semi-mythologically credited with building Dublin during his evangelical mission to Ireland. During this endeavor he is credited (by some) with inventing mortar to join blocks of stone together. Thus St. Patrick is the Patron Saint of Ceramic Engineers, and was traditionally feted by the New York State College of Ceramics at Alfred University (my alma mater) on St. Patrick's Day.

After around the 11th century, Romanesque architecture became influenced by the tradition of the scandinavian longhouse. Made of logs, with vaulted ceilings, the longhouse design was attempted with stone. This resulted in development of engineering insight which led to flying buttresses and radial fins to help counter the thrusting forces of tall masonry walls. The resulting structures were more elegant, airy, and used less material than the Romanesque architecture which it replaced. This "new style" is known as Gothic Architecture.

What I've described above is a very cursory overview, it is a rich field for investigation and merits several return visits in the future on this blog.

Next we will look at the Black Death of the middle ages, and how this plague had a profound effect on the development of masonry.

Enjoy St. Patrick's Day, and remember that he was one of the original ceramic engineers!

## Tuesday, March 16, 2010

### English Brick and Limey Sailors

Settlement of the Americas by English colonists meant that new buildings had to be made in the New World. Bricks were brought to the colonies in the holds of ships, used as ballast.

At the end of the seventeenth century, lime was used as a mortar for brick construction. Lime does not harden rapidly like portland cement; it hardens slowly as CO2 is absorbed from the atmosphere. Cement which will harden rapidly is known as hydraulic cement. (The development of hydraulic cement is an interesting chapter, the subject of tomorrow's blog.)

By the eighteenth century American brickmaking had come into its own. Colonial Williamsburg has an excellent program where the early brickworks have been reproduced, showing visitors how these early American bricks were made.

Brick laying methods, techniques and terminology were adopted directly from European masonry practice, and many of these terms are still used in American masonry today. For example, a brick "soldier course" refers to bricks laid vertically with the narrow edge facing outward; a brick "sailor course" refers to bricks laid vertically with the wide edge facing outward.

English sailors ate lime to prevent scurvy, becoming known as "limeys." English brick laid as sailor courses with early (lime) mortar were also limey sailors!

Several different techniques of laying courses (rows) of bricks are used by masons. The thickness of a masonry wall is determined by the layers of bricks, or "wythes." The different patterns created by the stacking arrangements of bricks all have different names for the types of bonds created. Flemish bond, stretcher bond, English bond, Header bond, Rat-trap bond, Herringbone bond and Basket bond are all examples of brick patterns found in early American homes and still in use by masons today.

Brick laying is a rich field of history, and many of these early structures still survive today. This is a subject we'll be coming back to in future blogs. The development of the American brick industry is practically its own subject which we'll be taking a long look at.

## Monday, March 15, 2010

### Black Death and Bricks

The Bubonic Plague ravaged Europe in a few successive waves throughout medieval times, claiming over one-third of Europe's population. Of particular interest is the "Black Death" or great plague of London from 1664-1665. This plague took a huge toll on England and on London in particular, as described in Daniel Defoe's A Journal of the Plague Year.

Defoe's book was an attempt to warn the public of the dangers inherent in the plague, a systematic and objective accounting of the plague and its human toll. The author used details to achieve verisimilitude; including specific places, streets, houses and neighborhoods. His was a very public warning.

The great plague of London was followed by another catastrophe for the city, the Great Fire of 1666. This fire began as a small blaze in the bakeshop of Thomas Farynor, on Pudding Lane in London. Soon the fire was out of control, and consumed many structures built of wood and pitch. By the time the fire was over (several days later) around 80% of the city was destroyed, including 430 acres of the city, 13,000 houses, 89 churches and 52 Guild Halls.

As a result of the great fire, London was redesigned and rebuilt. King Charles II established new laws for construction, dictating that all new buildings were to be made of brick. Sir Christopher Wren was commissioned to design some 50 new churches and other structures, including St. Paul's cathedral, all built of masonry. An interesting aside: funds to build St. Paul's cathedral were taken from the funds for St. Peter's in Westminster; the source of the expression "robbing Peter to pay Paul."

The results of the Great Fire were tremendous. First, it killed off much of the rat population -carriers of fleas that spread plague- and brought a definitive end to the great plague of 1664-1665. Secondly it established and greatly strengthened the masonry industry, including brick manufacture and the number of working masons.

Following the Great Fire, when trade ships plied the Atlantic for the New World, their holds were filled with brick as ballast. New houses built in the American settlements were made from this brick; brick which was available largely due to the Great Fire which ended the black plague of London in 1666.

Next time we'll look at this new masonry construction in the American settlements, and how masonry developed in the New World.

## Saturday, March 13, 2010

### St Patrick, Mason

Mediterranean architecture had a long history of masonry construction at the advent of Christianity as a religion. Typical Mediterranean masonry architecture included domed roofs, arches and thick stone walls.

With the gradual collapse of the Roman Empire and the spread of Christianity, evangelists brought their masonry construction techniques (as well as scripture) to northern Europe. Initially these construction techniques dominated as Romanesque architecture. This architectural style is characterized by round arches, thick walls, and generally stolid (unmovable, dull) and squat configurations; typically described as "over-engineered" and using a surplus of material, or "more than is needed."

Romanesque architecture endured and flourished across northern Europe for centuries. The existence of this architecture today is a testament to its high strength and robust design.

One of the unique evangelists who spread the gospel was St. Patrick (circa 420's AD) who brought Christianity to Ireland. He is semi-mythologically credited with building Dublin during his evangelical mission to Ireland. During this endeavor he is credited (by some) with inventing mortar to join blocks of stone together. Thus St. Patrick is the Patron Saint of Ceramic Engineers, and was traditionally feted by the New York State College of Ceramics at Alfred University (my alma mater) on St. Patrick's Day.

After around the 11th century, Romanesque architecture became influenced by the tradition of the scandinavian longhouse. Made of logs, with vaulted ceilings, the longhouse design was attempted with stone. This resulted in development of engineering insight which led to flying buttresses and radial fins to help counter the thrusting forces of tall masonry walls. The resulting structures were more elegant, airy, and used less material than the Romanesque architecture which it replaced. This "new style" is known as Gothic Architecture.

What I've described above is a very cursory overview, it is a rich field for investigation and merits several return visits in the future on this blog.

Next we will look at the Black Death of the middle ages, and how this plague had a profound effect on the development of masonry.

Enjoy St. Patrick's Day, and remember that he was one of the original ceramic engineers!

## Friday, March 12, 2010

### History of Masonry

A discussion of masonry should begin at the beginning. As long as shelter has been a concern for mankind, masonry has been part of the solution. Some of the the earliest shelters involved stone, using caves as habitable enclosures. This even pre-dates mankind as a species.

Neanderthal caves are known throughout Europe. Here is an interesting article on the neanderthal Vindija cave in Croatia. As humans advanced as a species, shelters began to move from caves to built structures. Contemporary scientific methods and engineering analysis provide a deeper understanding of early masonry structures.

Masonry developed across the "ancient world" as construction techniques developed from experience, trial & error, and the flash of human genius which produces great art and architecture. This is such a rich field of study that I'll be coming back to it repeatedly on this blog.

Greek and Roman architecture borrowed on the knowledge of those who came before them and developed masonry to a high art.

After the Roman Empire, Christian evangelists spread religion from its Mediterranean cradle to northern Europe. The hybridization of Mediterranean masonry architecture with the Scandinavian longhouse led eventually to the Gothic style. This is where we'll pick up next.

## Thursday, March 11, 2010

### Introduction

I'm a masonry designer developing novel masonry systems for new applications. This blog will describe what my ideas are, how I'm making them, various uses, and so on. I will share ideas and hope to get feedback from as many interested people as I can.

I'm especially interested in doing more with concrete block than is currently possible. I want to expand the architectural vocabulary of concrete block construction to include much more than straight vertical walls and square corners. This is pretty much the status quo with current block design and construction.

As a child I had the good fortune of seeing some of the great cathedrals of Europe. This experience left an indelible impression on me. It's probably why I do what I do; masonry architecture can be so much more than rectangular block and vertical walls. Arch, cylinder, dome and sphere should all be part of the masonry repertoire. This is possible with block manufacturing methods and materials, through innovative design.

This is an exciting realm that combines ages-old building techniques with current scientific  engineering knowledge and high-efficiency production methods.