Cement who invented

Before Portland cement was discovered, and for some years afterward, large quantities of natural cement were used, which were produced by burning a naturally occurring mixture of lime and clay. Because the ingredients of natural cement are mixed by nature, its properties vary widely.

Modern Portland cement is manufactured to detailed standards. Some of the many compounds found in it are important to the hydration process and the chemical characteristics of cement.

Eventually, the mix forms a clinker, which is then ground into powder. A small proportion of gypsum is added to slow the rate of hydration and keep the concrete workable longer. Between and , systematic tests to determine the compressive and tensile strength of cement were first performed, along with the first accurate chemical analyses. In the early days of Portland cement production, kilns were vertical and stationary.

In , an English engineer developed a more efficient kiln that was horizontal, slightly tilted, and could rotate. The rotary kiln provided better temperature control and did a better job of mixing materials.

By , rotary kilns dominated the market. In , Thomas Edison received a patent for the first long kiln. This was about 70 feet longer than the kilns in use at the time. Industrial kilns today may be as long as feet.

Although there were exceptions, during the 19 th century, concrete was used mainly for industrial buildings. It was considered socially unacceptable as a building material for aesthetic reasons. The first widespread use of Portland cement in home construction was in England and France between and by Frenchman Francois Coignet, who added steel rods to prevent the exterior walls from spreading, and later used them as flexural elements.

Wilkinson in In , American mechanical engineer William Ward completed the first reinforced concrete home in the U. It still stands in Port Chester, New York. Ward was diligent in maintaining construction records, so a great deal is known about this home. In , George Bartholomew poured the first concrete street in the U. The concrete used for this street tested at about 8, psi, which is about twice the strength of modern concrete used in residential construction.

Court Street in Bellefontaine, Ohio, which is the oldest concrete street in the U. Although in cement manufacturers were using more than 90 different formulas, by , basic testing -- if not manufacturing methods -- had become standardized. During the late 19 th century, the use of steel-reinforced concrete was being developed more or less simultaneously by a German, G. Ransome started building with steel-reinforced concrete in and patented a system that used twisted square rods to improve the bond between steel and concrete.

Most of the structures he built were industrial. Hennebique started building steel-reinforced homes in France in the late s. He received patents in France and Belgium for his system and was highly successful, eventually building an empire by selling franchises in large cities.

He promoted his method by lecturing at conferences and developing his own company standards. As did Ransome, most of the structures Hennebique built were industrial. In , Wayss bought the rights to a system patented by a Frenchman named Monier, who started out using steel to reinforce concrete flower pots and planting containers. Wayss promoted the Wayss-Monier system. In , August Perret designed and built an apartment building in Paris using steel-reinforced concrete for the columns, beams and floor slabs.

The building was widely admired and concrete became more widely used as an architectural material as well as a building material. Its design was influential in the design of reinforced-concrete buildings in the years that followed.

In , the first concrete high-rise building was constructed in Cincinnati, Ohio. It stands 16 stories or feet tall. In , the first load of ready-mix was delivered in Baltimore, Maryland. The building had an automobile test track on the roof. In , he built two gigantic parabolic-arched airship hangars at Orly Airport in Paris.

In , he was granted a patent for pre-stressed concrete. Air entrainment was an important development in improving the durability of modern concrete. Air entrainment is the use of agents that, when added to concrete during mixing, create many air bubbles that are extremely small and closely spaced, and most of them remain in the hardened concrete.

Concrete hardens through a chemical process called hydration. For hydration to take place, concrete must have a minimum water-to-cement ratio of 25 parts of water to parts of cement. Water in excess of this ratio is surplus water and helps make the concrete more workable for placing and finishing operations.

As concrete dries and hardens, surplus water will evaporate, leaving the concrete surface porous. Water from the surrounding environment, such as rain and snowmelt, can enter these pores. Freezing weather can turn this water to ice. As that happens, the water expands, creating small cracks in the concrete that will grow larger as the process is repeated, eventually resulting in surface flaking and deterioration called spalling. When concrete has been air-entrained, these tiny bubbles can compress slightly, absorbing some of the stress created by expansion as water turns to ice.

Entrained air also improves workability because the bubbles act as a lubricant between aggregate and particles in the concrete. Entrapped air is composed of larger bubbles trapped in the concrete and is not considered beneficial. The result was the world's first hydraulic cement: one that hardens when water is added.

Aspdin dubbed his creation Portland cement due to its similarity to a stone quarried on the Isle of Portland, off the British coast.

In , this brilliant craftsman obtained a patent for what would prove to be the world's most ubiquitous building material, laying the foundation for today's global Portland cement industry. Portland cement - a combination of calcium, silica, aluminum and iron - is the fundamental ingredient in concrete. Producing a calcium-silicate Portland cement that conforms to specific chemical and physical specifications demands careful control of the manufacturing process.

First, the raw materials - limestone, shells or chalk along with shale, clay, sand or iron ore - are mined from a quarry that's usually near the manufacturing plant. Before leaving the quarry these materials are reduced in size by two sets of crushers.

Then the raw materials are sent to the manufacturing plant, where they are proportioned to create cements with specific chemical compositions. In the dry method, dry raw materials are proportioned before being ground into a fine powder, blended, then fed dry into a kiln.

In the wet method, a slurry is created by adding water to properly proportioned raw materials prior to them being ground, blended and fed into the upper end of a tilted and rotating cylindrical kiln, where their rate of passage is controlled by the kiln's slope and rotational speed.

Burning fuel - usually powdered coal or natural gas - is then forced into the kiln's lower end, heating the raw materials to 2,, degrees F 1,, degrees C.

At 2, degrees F 1, degrees C , several chemical reactions fuse the raw materials, creating what are called cement clinkers: grayish-black pellets the size of marbles. The red-hot clinkers are discharged from the lower end of the kiln and transferred into various types of coolers to reduce their temperature so they can be handled safely. Now cooled, the clinkers are combined with gypsum and ground into a gray powder so fine that it can pass through a micron - or number mesh - sieve.

The flexibility of Portland cement is evident in the different types, which are manufactured to meet various physical and chemical requirements. Cement production and applications surged globally at the turn of the century. Since the s, rotary kilns replaced the original vertical shaft kilns, as they use radiative heat transfer, more efficient at higher temperatures. Gypsum is now also added to the resulting mixture to control setting and ball mills are used to grind clinker. Other developments in the last century include calcium aluminate cements for better sulphate resistance, the blending of Rosendale a natural hydraulic cement produced in New York and Portland cements to make a durable and fast-setting cement in the USA, and the increased usage of cementitious materials to store nuclear waste.

New technologies and innovations are constantly emerging to improve the sustainability, strength and applications of cement and concrete. Some advanced products incorporate fibres and special aggregates to create roof tiles and countertops, for example, whilst offsite manufacture is also gaining prominence with the rise of digitalisation and AI, which could reduce waste and improve efficiency and on-site working conditions.

Cements and concretes are also being developed which can absorb CO 2 over their lifetimes, reducing the carbon footprint of the building material. Our newsletters are Powered by AWeber.

We respect your email privacy. History of Cement The Long Road to Today's Portland Cement Ancient History: Cement has been in use by humans throughout history; variations of the material were used up to 12, years ago, with the earliest archaeological discovery of consolidated whitewashed floor made from burned limestone and clay found in modern-day Turkey.

The Middle Ages The Middle Ages were a quiet time in the history of cement; any discoveries made during this era remain unknown, although masons are known to have used hydraulic cements to build structures such as fortresses and canals.

The Birth of Portland Cement: The precursor to modern-day cement was created in by Joseph Aspdin, a British bricklayer and builder, who experimented with heating limestone and clay until the mixture calcined, grinding it and then mixing it with water.