Spherical Block LLC: New Ways to Build with Masonry

Words: Peter Roberts

Spherical Block LLC is launching a revolution in advanced masonry technology. Roofs are made as arches and domes from concrete block, using efficient methods of assembly and green materials to make beautiful masonry structures. The company’s new products and designs create new markets for masonry construction. The company’s technologies make better buildings at a lower cost, assembled efficiently and safely. Structures made with these technologies will better withstand extreme weather events, wildfires, tornadoes, and hurricanes. A new world of design is possible with these technologies, creating beautiful, resilient, energy-efficient, welcoming buildings. The benefits of concrete block masonry extend from the walls to the roof. Spherical Block LLC was first featured in Masonry Magazine in August 2020. This article provides an update on the company’s more recent developments.

Traditionally, CMUs have only been used to build straight vertical walls. For over a hundred years, the CMU has done this job very well by providing great value for any building. The benefits of CMU construction include low cost, high strength, durability, fire safety, insect resistance, mold, rot, and rust resistance, sound attenuation, all coupled with a variety of appearances made possible through colors added and split-face textures; all made with tight dimensional tolerances in a highly efficient manufacturing process. This high efficiency and low cost have brought the concrete block to virtually every country and have made it a staple of high-quality, affordable construction on a global basis. In addition, CMUs possess high thermal mass, which can help make a building more energy-efficient when properly assembled with correct placement of thermal insulation. Buildings made with CMUs have a high resale value and a long, useful life cycle.

This masonry system creates extensive design flexibility for the architect, designer, planner, and ultimately the end user. This groundbreaking innovation is at the nexus of high-efficiency modern manufacturing and traditional masonry arches rooted deep in the past. The end result is a beautiful array of architectural options that are affordable, easy to build, very high strength, fire safe, and available wherever you find concrete block.

Semi-Automated Assembly
The company is performing the developmental work of combining two existing technologies to make semi-automated masonry assembly possible. First, mortar is deposited using 3-dimensional concrete printing (3DCP) methods. This can be done with either a gantry-based system or a robotic arm-based system. Using a robotic arm system, no frame is required to be erected, as needed for any gantry-based system. Recent improvements in the stabilization of the robotic arm make the robotic arm faster, more efficient, and less expensive than gantry systems. Horizontal beds of mortar are easily and rapidly deposited using 3DCP equipment, providing a uniform, even thickness of mortar.

Spherical Block LLC is working with Sustainable Construction Solutions, which uses Constructions 3D’s MaxiPrinter robotic arm 3DCP equipment. The MaxiPrinter unit has retractable legs which stabilize it and is able to fit through a doorway and be set up. Vertical joints of mortar are readily deposited by simply placing CMUs in a vertical orientation, so that the mortar joint is horizontally deposited on the end of a row of adjacent blocks. The blocks are rotated 90° before they are placed, so that the head joint mortar becomes vertically oriented as it is placed in the horizontal bed of mortar.

CMUs are picked up by the MULE robotic unit, provided by Construction Robotics. The CMUs are rotated 90° and are then placed in the horizontal mortar bed by a mason. The process is repeated until a complete course is assembled. Once an entire course of block is placed, the 3DCP equipment then lays another bed of mortar on top of those CMUs, and the process is repeated.

This method increases the height of a vertical wall being assembled by 8 inches with each pass of 3DCP mortar, rather than the half inch or so normally gained with each pass of conventional 3DCP. The "sausage effect" of cementitious 3DCP material bulging with each layer and creating a non-uniform vertical surface is removed with this method. A regular masonry appearance is created, with tight dimensional tolerances and smooth, even surfaces. The beauty of masonry distinguishes this new use of 3DCP.

Walls assembled using 3DCP methods to deposit mortar combined with masonry will not slump or deform, like conventional 3DCP. This method will not create problems with cold joints delaminating, like conventional 3DCP. The sensitivity of 3DCP timing is removed by including CMUs between each layer of 3DCP material.

Green Cements
Resiliency is critical to green construction. The longer a building lasts, the lower its carbon footprint. High-strength materials used in construction result in resilient, long-lived buildings. CMUs assembled with basaltic FRP rebar provide rust-free rebar with corrosion resistance. These buildings will not rot, rust, or burn. They are designed for centuries.

Green cements can further reduce the carbon footprint of this masonry system. Spherical Block LLC is partnering with Geopolymer International (GPI) to use geopolymer in masonry construction. GPI’s geopolymer material creates 88% less CO2 than OPC.

Spherical is also using other green cements and SCMs. Brimstone produces OPC from carbon-neutral materials. Block producers are accustomed to using OPC, and they are familiar with it. Additional supplementary cementitious materials (SCM) can be used to make high-strength affordable low-carbon CMUs.

Spherical is working with basaltic FRP rebar provided by Smarter Building Systems. This rebar has a high tensile strength and is exceptionally resistant to chemical attack and corrosion (e.g., resistant to saltwater corrosion). This material is lightweight and easily provides the curved surfaces required for arch and dome roofs. Smarter Building Systems has this material available in a number of thicknesses and configurations, including as a mesh or grid.

Porosity of damp-cast manufactured block provides carbon sequestration around 1,000 times faster than non-porous wet-cast concrete. Masonry block buildings will absorb CO2 much faster than those made of wet-cast concrete.

What's Been Done
Spherical Block LLC is selling both Dome and Arch blocks at Southern Tier Concrete Products in Alfred, NY. Full-size Arch Block are $1.93 each, two halves are $1.02 each. Dome blocks are $4.23 each ("hex" or "pent"). Cost does not include delivery.

Spherical Block is licensing its molds to block producers everywhere. Spherical’s support includes demos for assembly and classes for masons. Our team includes Besser Company, Construction Robotics, Geopolymer International, Sustainable Construction Solutions, Smarter Building Systems, and Southern Tier Concrete Products. Product Listings and Evaluation Reports from the International Code Council – Evaluation Services (ICC-ES) have been obtained by Spherical Block. New ICC-ES certifications for Spherical’s products can readily be obtained by licensed block producers.

Spherical Block has a prototype building available as a short-term rental on Airbnb and VRBO. Guests are invited to experience this new masonry system first-hand. This unique masonry building is close to Southern Tier Concrete Products and Alfred University.

What’s Next
Spherical Block LLC and its team of partners are currently developing the semi-automated assembly method that incorporates Sustainable Construction Solutions’ MaxiPrinter to 3DCP deposit mortar and Construction Robotics’ MULE to help place blocks in the mortar. This technique is being documented and tested and is expected to be commercially available soon.

Spherical Block LLC, Geopolymer International, Sustainable Construction Solutions, and Construction Robotics plan to work with MCAA’s Jeff Buczkiewicz and others to assemble and test this masonry system, this fall (2024) in Texas. A video production is planned, where the team plans to dramatically demonstrate how resilient, tough, robust, and strong this masonry system is. The team expects to use engaging methods to showcase this technology, including heavy loads being dropped on buildings, explosions, and even flamethrowers.

Designs
There are three basic types of blocks which all work together in the design and assembly of masonry arched roof structures. These designs are all described in US Patents issued and assigned to Spherical Block. Molds to produce these blocks have been manufactured for the company by Besser Company. The molds have demonstrated their ability to produce these innovative masonry units with ease. These molds can operate on either Besser or Columbia type block-making machines which are already operating in every global market.

Arch Block
The arch block is a rectangular, solid cast unit with two grooves to accept rebar. The dimensions of this block are 8 inches x 16 inches by around 3 inches. The shape has a compound angle in it so that when it stacks it assembles into an arch. This simple design allows for a number of interesting and useful architectural features to be made. Rebar provides support during assembly so that centering (supporting scaffolding) can be minimized or even done away with completely. This provides for rapid, simple, and affordable assembly.

Spherical’s molds operate on a 3-at-a-time block machine (a machine which produces 3 standard 8-inch x 8-inch x 16-inch rectangular CMUs). These arch block molds will produce 8 arch blocks per cycle, with a cycle time of around 8 seconds: so that arch blocks are made in around 1 second each. The cavities in the arch block mold can be arranged with a divider plate, to produce two half-blocks, which are used at the termination of an arch.

* Door and window arches
* Flying buttresses
* Corrugated arches
* Smooth arches

Hex Block & Pent Block for Dome Roofing
The “hex” and “pent” are triangular blocks used to assemble into spheres or sections of spheres, such as domes. Six hex blocks assemble into a curved hexagon, and five pent blocks assemble into a curved pentagon. There are a number of geodesic geometries that these two blocks can assemble into, both together and each by itself. By using a larger number of blocks within any specific geometry, different sized structures (domes and spheres) can be made. These blocks have a groove located in each of its three abutting faces to accept rebar. This lets the blocks be supported by a framework of rebar, so that minimal or no centering or support scaffolding is required.

Ease of Manufacture
All of Spherical Block's designs are easy to manufacture on both Besser and Columbia type machines. No special materials or handling equipment are required for their production. The molds are mounted on the machine, and standard production using regular concrete mix designs begins. The arch block can be handled, moved, cubed, and palletized using standard automated block production equipment. The hex and pent blocks are easy to palletize with minimal manual manipulation. All three types of blocks have dimensions that correspond to the standard modular coordination for concrete block, allowing for convenient and regular stacking on shipping pallets.

Ease of Assembly
Spherical Block's masonry units are relatively simple and easy to assemble. There is a slight learning curve for the mason to gain familiarity with the various configurations made available by this masonry system. The arched roof sections or domes can either be sprung directly from the foundation or placed on top of vertical walls. The vertical walls must be strong enough to support a concrete block roof; they cannot be standard wooden "balloon frame" construction made of wooden studs. It is recommended that vertical walls be made from standard concrete block of 8-inch thickness or more.

#3 rebar (3/8-inch diameter) is recommended for arched roof and dome construction. Rebar is arranged at 8-inch intervals and is anchored in either the vertical walls (extending down into the core holes of the block) or is anchored directly into the foundation. The rebar is curved into the arc of the roof structure (arch or dome) to create a support structure on which blocks are laid. Blocks are then laid with mortar, in a manner quite similar to which standard vertical masonry walls are assembled. A specific, detailed description of the assembly for various structures is beyond the scope of this article: this is simply intended to provide a general overview of the assembly method. It is recommended that a form be provided on the inside of the arch to help the mason create an accurate and more precise arch profile.

Energy Efficiency
This masonry system takes advantage of the thermal mass benefits created by using a complete masonry building envelope. Masonry has a high specific heat (thermal mass) which provides the ability for the building envelope—including walls and roof—to store heat energy and subsequently release this heat energy back to the inside of the building. This concept also applies to both keeping a building warm in cold weather and keeping a building cool in hot weather. In order to maximize this thermal mass benefit, it is recommended to place thermal insulation on the outside of the masonry building envelope, like wrapping a warm stone in a cozy blanket. This arrangement creates a delay from the time it takes cold temperatures during winter (or hot temperatures during summer) to travel through the building and affect the interior. This delay also creates a lag on the peak energy demand: that time of day when everyone’s heat has to go on to warm a building, or when everyone’s air conditioning turns on to cool their homes. This delay significantly reduces the peak energy demand for a power grid, and power grid requirements are defined by their peak demand.

Safety
Concrete block masonry is long known to be safer than competing forms of construction, such as wooden framing. This is known even by children, as demonstrated by the tale everyone is familiar with: the story of the three little pigs and the big bad wolf. Masonry buildings can withstand high winds and severe weather events better than wood frame structures. However, in America timber frame homes have long dominated the residential market. Spherical Block’s technology extends the fundamental safety of masonry construction all the way to the top of the roof for any building or structure. Manufactured concrete blocks do not have the same strength in all directions; it is known as anisotropic material. That is, concrete block has a high-strength axis, which is the direction of compaction as blocks are made. In conventional CMUs, this high-strength axis is oriented vertically within a wall. This means that the low-strength axis is oriented horizontally, toward the outside with standard CMUs. Spherical Block’s designs always have the high-strength axis oriented toward the outside so that the building is much better protected from impacts or forces that might hit the building. This is due to the orientation of aggregate within the manufactured concrete, as shown by research conducted by Spherical, as illustrated in this micrograph. The end result is a structure around 70% stronger than standard CMU buildings.

Tornado and Hurricane Safety
Tornadoes and hurricanes frequently cause extensive damage to buildings and homes every year. It is common to see homes with their roofs ripped off, damaged, or destroyed following either a tornado or hurricane. Spherical Block alleviates this threat by providing buildings that can withstand the extreme forces and loading created by both tornadoes and hurricanes. This technology provides safer, more secure homes for communities living in areas prone to either tornadoes or hurricanes. Climate change is increasing the risk and vulnerability of homes, buildings, and shelters as extreme weather events and the damage they create are expected to continue to rise.

Wildfire Safety
Recent wildfires across the American West (especially in California) have reminded us all of how dangerous and lethal wildfires are, and how easily standard wooden homes are destroyed by fire. Spherical Block’s designs are very well suited to withstanding this threat by extending the non-combustible, fireproof concrete block all the way to the top of the roof. Burning embers can be carried aloft for miles and create a significant threat when they land on a combustible roof. One of the most dangerous threats in a burning building is a collapsing roof, which is, sadly, responsible for many tragedies every year. Spherical Block’s building systems remove this threat and increase the safety of buildings and homes. Because these blocks are solid, they create a greater thickness of concrete between the outside and interior of a building. This thickness of non-combustible concrete translates directly into an increased fire safety rating, which is expressed in hours of safety provided. Typical CMUs provide around a 2–2.5-hour fire safety rating. This technology is expected to provide around a 4–6-hour fire safety rating, due to the increased thickness provided by solid concrete construction (fire safety testing is still required to confirm this expectation). Once this fire safety rating is confirmed, buildings made with Spherical Block LLC’s technology properly configured (including airtight rooms, proper fire windows, doors, etc.) will provide people with the ability to shelter in place and survive wildfires.*

Too many people evacuating their homes during a wildfire have been killed in the act of evacuation; traffic is often stopped and fires move quickly. The ability to shelter in place in a safe and secure building removes this threat. The affordability and ease of assembly of this technology offer the promise of fire-safe buildings made available to homeowners everywhere.

Unique New Applications
The unique nature of Spherical Block LLC’s masonry designs makes several exciting and entirely new applications and uses for masonry available.

The hex and pent blocks can be used to assemble an entire sphere. This arrangement creates the ability to provide storage tanks which are affordable, very strong, and easy to install for multiple applications. These tanks can be used for rainwater harvesting (RWH) where the roof of a building serves as the catchment area for rainfall, and gutters collect and divert rainwater for storage in one of these spherical tanks. These spherical tanks can also be used as septic tanks.
These septic tanks are much less expensive than conventional monolithic cast concrete septic tanks, and do not require a crane and/or heavy equipment for installation.
The arch blocks can be used to assemble as a load-bearing arch and can be used as a bridge. This application can help fulfill a huge need for infrastructure in the US: currently, concrete bridges have a relatively short useful life cycle of around 50–100 years.

By contrast, the masonry arch structures used by the ancient Romans in their aqueducts (used to deliver potable water to cities) are still standing strong after 2,000 years. By using fiber-reinforced plastic rebar, Spherical Block LLC’s masonry arches will not suffer from rust damage which leads to the short life cycle of typical concrete bridges, which are prone to failure following the rust and degradation of concrete due to metal rebar.*

Sell More Block
Producers who license and sell Spherical Block’s products will sell more standard CMUs. This is due to the fact that this roofing system works best when assembled on top of vertical walls made from CMUs. That is, a building made with Spherical’s roofing products will have the entire building made from CMUs. This will result in many more blocks sold by the block producer than are sold for a typical building made using CMUs: not just CMUs used for a stem wall, not just vertical walls made with CMUs, but the entire building made from CMUs.

Spherical Block LLC: New Ways to Build with Masonry

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