Though diamond polishing is the newest chapter in the evolution of concrete, the process unites two of the oldest materials in the world: diamonds and cement.

The Romans, who used concrete in 300 BC to build such marvels as the Coliseum and Pantheon, could not have imagined the possibilities of the material they paved over five-thousand miles of roads with. The colors and finishes developed in the past century allow installers to design and even to become artists—with concrete as their canvas. These endless application opportunities, including beautiful polished flooring, would be impossible without the journey concrete has taken throughout history.

Created by underground combustion of limestone and oil shale, natural cement is as old as the earth itself; however, its bonding power was not harnessed until humans discovered elemental concrete mixtures of lime, sand, and gravel. The ancient Chinese utilized early combinations of volcanic ash and lime to create the Shaanxi pyramids, and the Egyptians built their famous pyramids with mud and straw bricks bound by cementious mortars. The great structures of the Roman Empire were built with concrete made from quicklime, sand, pozzolanic ash and aggregate. The most similar to modern concrete, Roman admixture technology was lost during the Middle Ages. Concrete disappeared for nearly thirteen centuries, until John Smeaton, a British engineer called the Father of Civil Engineering, was charged with rebuilding the Eddystone Lighthouse (Cornwall, England) in 1756. While searching for a material that would not be affected by water, he used powdered brick and small stones as aggregate to develop a hydraulic mortar widely regarded as the beginning of modern concrete.

Smeaton’s contributions lead to the formal discovery of Portland Cement, the most widely used component of concrete today, by Joseph Aspdin in 1824. Cement technology began to advance rapidly in the latter half of the nineteenth century: the first concrete-reinforced bridge was built, and Ohio became home to both the first concrete high-rise, and concrete street.

The birth of decorative concrete emerged from both technical advances and craftsman experimentation. Advances in admixtures including accelerators, retarders, plasticizers, corrosion inhibitors and bonding agents allowed cement to be used in new ways, limited only by the creativity of artisans.

Experimentation with color and pigment to vary the aesthetic effect of concrete began in the early 1900s, but efforts with specific blends were limited and end results lacked consistency. Though promising research was being done on a small scale, any formulas were created on an individual basis, and uniformity could vary within a single project.

The architect Gilbert Stanley Underwood is famous for using original chemical stains in the Yosemite Valley Awhanhee Hotel, but Lynn Mason Scofield, founder of the L.M. Scofield Company, is credited with being the first manufacturer to create products specifically designed for reliable concrete coloration. In 1915, when he was a young engineer, Scofield developed proprietary color systems for beautifying concrete including integral color, chemical stains and color hardeners. He was the first to archive and mass-produce color compounds, thereby making their use practical for the industry.

During the 1920s and 1930s, when Art Deco and Art Nouveau architects in Southern California were setting styles in Old Hollywood, stars like Charlie Chaplin, Fred Astaire, Bing Crosby and Groucho Marx glamorized colored concrete by using it in their homes.

The advances in coloration since those times now permit contractors to add a rainbow of options to freshly poured and existing concrete. By adding integral pigments before pouring, color may be spread throughout the entire mixture. Alternately, already hardened concrete may be hued by dyes or tints, which impart distinction after absorbing into the substrate. Stains may also be utilized on a cured surface; the chemical reaction between the mixture’s metallic salts and the hardened surface create an insoluble saturation that enhances existing aggregate, often creating a marble-like tone. Craftsman can conjoin dyes and

chemical stains, weaving them together to fabricate a virtually unlimited array of colors.

Innovation that began with the introduction of color to concrete continued with stamping. In the 1950s Brad Bowman invented the Bomanite process of stamping patterns into concrete with aluminum tools. His research in imprinted, architectural, and patterned concrete inspired others to improve upon his ideas. Jon Nasvik was a forward-thinker who developed light, long-lasting plastic stamps in the 1970s. His designs furthered the possibilities of concrete design, and were used in the construction of Disneyworld’s EPCOT. Stamped concrete was officially introduced to the industry at the 1978 World of Concrete, and ushered in the era of modern decorative concrete.

Concrete stenciling, pioneered in the 1970s, yielded a new dimension to the craft. After observing the patterns autumn leaves imprinted on freshly poured concrete, Gerald Brasseaux originated a paper-stenciling process by which patterns could be inlaid. The craft advanced when grave marker plastic adhesive template technology was adapted for concrete. The adhesive stencils were originally cut by hand, but thanks to Glen Roman of Brickform, computers with drawing and plotting

applications are used today. The precision of computers combined with the ingenuity of custom stenciling allows for embedded decorative logos, borders, crests, and more.

The most recent stop in concrete’s journey from dull to delightful is dry-polished concrete. Though concrete had been wet-polished for many years in Europe, dry-polishing was discovered in the late 1990s. The story is told that a contractor was retained to polish the floors of a palace. He assumed his workers knew the process used water, but they did not—so in his absence they began polishing the surface dry. Upon his return, immediate dismay turned to disbelief when he realized that the dry polishing had created a beautiful floor, without the mess of water. He notified his European supplier of the development who in turn began to research and produce equipment for dry polishing. The process was perfected in the United States when manufacturers drew on natural stone masonry experience and computer technology to create tools specifically for the dry polishing process. Groups of contractors pushed the process into the market, and the tools became more refined as they tried and tested the products. Today, dry diamond polishing equipment enables contractors to create a hard glass-like finish that is economical, efficient, and beautiful.

Polished concrete brings together all other design elements by allowing them to be used-- then polished to a low sheen or high shine. It offers an array of beauty, color and style with the added benefits of long-wear and low maintenance. Many of the techniques mentioned in this article require special sealants and coatings which must be reapplied every few years. If the flooring is finished by dry-polishing, these steps, along with their added time and expense, are unnecessary.

In the past only shades of flat gray were associated with concrete, but the salt and pepper aggregates of today are quickly fading into the bright colors and contours of concrete’s tomorrow. With the marriage of timeless natural elements and modern technology, polished concrete has birthed a new generation of polished concrete floor.