Mechanical Concrete
Mechanical Concrete is a building material that uses stronger materials and is an advancement in geocellular confinement systems, which were pioneered by the U. S. Army Corps of Engineers beginning in 1975.
Geo-cylinder confinement is made by using a cylindrical segment to mechanically confine crushed stone, soils, or other aggregate materials, creating a cellular, load-supporting unit. Arranged in horizontal or vertical configurations, collections of the units may be used for load support to form roadway bases and foundations; for earth-retention to build bearing and retaining walls, dams, and other wall structures; and for slope and channel protection to resist storm water erosion and protect stream banks.
This technology was invented in 2004 by Samuel G. Bonasso, a professional civil engineer, a former secretary of the West Virginia Department of Transportation and former deputy administrator of the Research and Special Programs Administration and of the Research and Innovative Technology Administration of the U.S. Department of Transportation.[1]
Research, laboratory testing and field demonstration beginning in the spring of 2005 led to its acceptance in October 2008 for roadway construction in the state of West Virginia by the West Virginia Department of Transportation.[2]
The U.S. Patent and Trademark Office awarded Mechanical Concrete a patent in 2008[3][4] and the technology has since been licensed by Bonasso’s Reinforced Aggregates Co. of Morgantown, W.Va. By mid-2011, the technology had seen success in West Virginia,[5] was in use in road construction in commercial and public sector applications in four other states — Arizona, California, Ohio, and Pennsylvania — and had been presented to international audiences.[6]
Concrete[edit]
What is usually called concrete is made by combining a cementing mixture, usually Portland cement, and water with mineral aggregates: sand and gravel. The cement and water undergo a chemical reaction that causes the mixture to harden, or cure; when poured into a form, the chemical reaction binds and integrates the whole into a desired shape.
In Mechanical Concrete, the geo-cylinder replaces the cement, water, and forms, offering a “mechanical” confinement rather than a “chemical” means of binding aggregates together. It further functions as a lateral reinforcing element and as a stay-in-place forming device. Together, the cylinder and aggregates form a three-dimensional mass capable of supporting and transmitting applied loads.
How Mechanical Concrete is made[edit]
In its most general description, Mechanical Concrete is created by taking a sufficiently strong, structural, thin-walled, cylindrical segment made of any tensile material and filling this cylinder with a suitably strong granular aggregate compressive material.
A common, available form of Mechanical Concrete combines a tire-derived geo-cylinder — a used vehicle tire with both sidewalls removed — with crushed limestone, soil, or recycled aggregate. The tire-derived geo-cylinder confines and integrates the soil or stone into a functioning, load-supporting unit, analogous to brick or block. It functions and performs in applications similar to the geocell.
Mechanical Concrete tire-derived geo-cylinders may be combined in various three-dimensional configurations analogous to large bricks or blocks. To preserve overall structural geometry during stone-filling operations, each cylinder is attached to its adjacent cylinder with a tie, nail or other suitable device. Once the structure is built, the mass and internal friction maintain the structural geometry.
On average, 10 to 12 automobile tires create one cubic yard of Mechanical Concrete and 12,000 tire-derived cylinders create a 12-foot-wide, mile-long lane of roadway and 8000 to cover one acre.
Uses and Applications[edit]
Collections of Mechanical Concrete tire-derived geo-cylindrical units are suitable for use as a roadway base, as a building foundation on most types of soil, as a bearing or retaining wall, as a material for constructing dams and levees and for revetments, fills, storm water retention structures, and other bearing-type load-supporting structures in architectural and civil engineering. Collections of Mechanical Concrete cylinders may be stacked into columns in a wide variety of configurations of constant or varying height, width and length.
Because the Mechanical Concrete material made with crushed stone is load-bearing, porous, and permeable, it can also be used for a variety of water drainage control, slope and channel erosion protection, and water filtration applications.
When made from tire-derived geo-cylinders, Mechanical Concrete is a highly energy-absorbing material, due to the partial fluid properties of the stone aggregate and the elasticity of the tire tread cylinder. This energy-absorbing characteristic suggests its use as highway crash barriers for both low-speed and high-speed situations. It also suggests its use as a base isolation material in some earthquake prone regions. It can provide an inexpensive base-isolation alternative for new and retrofit mobile home and residential foundations; in addition, it offers a new material for a rational design approach to larger base isolation structures.
Since 2006, it has been used to build public access and private industrial road bases in California, Arizona, West Virginia, Ohio, and Pennsylvania.
Because of its simplicity and ease of construction, Mechanical Concrete can assist developing regions globally in building and maintaining low-cost, reliable, all-season farm-to-market rural roads with local labor, materials and equipment.
Mechanical Concrete was exhibited at the 10th International Conference on Low-Volume Roads hosted in July 2011 by the Transportation Research Board of the National Academies.
External links[edit]
References[edit]
- ↑ Pam Kasey (2006-06-08). "Bonasso Devises New Use for Old Tires". The State Journal.
- ↑ West Virginia Department of Transportation approval letter, Oct. 2008.
- ↑ US patent 7470092, Samuel G. Bonasso, "System and method for reinforcing aggregate particles, and structures resulting therefrom", issued 2008-12-30
- ↑ Pam Kasey (2009-01-15). "W.Va. Engineer Patents Way to Reuse Old Tires". The State Journal.
- ↑ Pam Kasey (2010-12-21). "Road Technology Finds Use in Marcellus Fields". The State Journal.
- ↑ Dana Arquilla (2011-08-12). "Mechanical Concrete Concept May Go International". WBOY.com. Archived from the original on 2011-09-28.
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