Self-drying concrete technology is found in certain cementitious patching and leveling materials and tile-settingmortars used in the flooring industry. Self-drying technology allows the cement mix to consume all of its mix water while curing, eliminating the need for excess water to evaporate prior to installing flooring. Traditional floor coverings, such as VCT, sheet vinyl, carpet and ceramic tile, can be installed before the material is completely dry and as soon as it hardens, which typically happens in the first two hours after placement.
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement that hardens over time—most frequently in the past a lime-based cement binder, such as lime putty, but sometimes with other hydraulic cements, such as a calcium aluminate cement or with Portland cement to form Portland cement concrete. Many other non-cementitious types of concrete exist with different methods of binding aggregate together, including asphalt concrete with a bitumen binder, which is frequently used for road surfaces, and polymer concretes that use polymers as a binder.
Mortar is a workable paste used to bind building blocks such as stones, bricks, and concrete masonry units, fill and seal the irregular gaps between them, and sometimes add decorative colors or patterns to masonry walls. In its broadest sense, mortar includes pitch, asphalt, and soft mud or clay, such as used between mud bricks. Mortar comes from Latin mortarium meaning crushed.
Traditional concrete has a water:cement ratio of about 0.5, which refers to the weight of the water divided by the weight of the cement. A water:cement ratio of 0.5 provides good workability while keeping the amount of excess water in the mix fairly low. Without at least this much extra water, the concrete would be too dry to place.
The chemical reaction of Portland cement and water that is known as hydration, which is necessary for the strengthening of the concrete, requires a water:cement ratio of only about 0.25. With a water:cement ratio of 0.5, there is twice the amount of water in the concrete mix than what is needed for hydration. This excess water needs to evaporate before flooring can be installed. Note: The magical number of 28 days defines only the designed strength of the concrete but has nothing to do with the dryness of it. E.g. A 10-year-old concrete slab can contain more moisture than a 28-day-old slab! Conversely, a self-drying concrete blend consumes all of its mix water with a water:cement ratio of up to 0.6, maintaining good workability while allowing flooring to be installed before it is completely dry.
Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the late 19th century by Joseph Aspdin, and usually originates from limestone. It is a fine powder, produced by heating limestone and clay minerals in a kiln to form clinker, grinding the clinker, and adding 2 to 3 percent of gypsum. Several types of Portland cement are available. The most common, called ordinary Portland cement (OPC), is grey, but white Portland cement is also available. Its name is derived from its similarity to Portland stone which was quarried on the Isle of Portland in Dorset, England. It was named by Joseph Aspdin who obtained a patent for it in 1824. However, his son William Aspdin is regarded as the inventor of "modern" Portland cement due to his developments in the 1840s.
There are also cement products that are partially self-drying, meaning that they use a high percentage of their mix water for hydration as opposed to using 100% of it. This type of product might be used when the flooring does not need to be installed the same day but must still be installed more quickly than traditional concrete would allow. For instance, products that are 80% self-drying allow flooring to be installed the next day, typically after a 16-hour cure.
Self-drying technology was developed by Ardex in Germany and was introduced in the United States in 1978.
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Flooring is the general term for a permanent covering of a floor, or for the work of installing such a floor covering. Floor covering is a term to generically describe any finish material applied over a floor structure to provide a walking surface. Both terms are used interchangeably but floor covering refers more to loose-laid materials.
In chemistry, efflorescence is the migration of a salt to the surface of a porous material, where it forms a coating. The essential process involves the dissolving of an internally held salt in water, or occasionally in another solvent. The water, with the salt now held in solution, migrates to the surface, then evaporates, leaving a coating of the salt.
Ferrocement or ferro-cement is a system of construction using reinforced mortar or plaster applied over an "armature" of metal mesh, woven expanded-metal or metal-fibers and closely spaced thin steel rods such as rebar. The metal commonly used is iron or some type of steel. The cement is typically a very rich mix of cement and sand in a 3:1 ratio; and when used for building boats nor gravel is used, so that the material is NOT concrete.
Shotcrete, gunite or sprayed concrete is concrete or mortar conveyed through a hose and pneumatically projected at high velocity onto a surface, as a construction technique, first used in 1914. It is typically reinforced by conventional steel rods, steel mesh, or fibers.
Ready-mix concrete is concrete that is manufactured in a batch plant, according to a set engineered mix design. Ready-mix concrete is normally delivered in two ways.
Lime is a calcium-containing inorganic mineral composed primarily of oxides, and hydroxide, usually calcium oxide and/ or calcium hydroxide. It is also the name for calcium oxide which occurs as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. The word lime originates with its earliest use as building mortar and has the sense of sticking or adhering.
Duff A. Abrams was an American researcher in the field of composition and properties of concrete. He developed the basic methods for testing concrete characteristics still in use today. A professor with the Lewis Institute, he studied the component materials of concrete in the early 20th century.
Superplasticizers (SP's), also known as high range water reducers, are additives used in making high strength concrete. Plasticers are chemical compounds that enable the production of concrete with ca. 15% less water content. Superplasticers allow reduction in water content by 30% or more. These additives are employed at the level of a few weight percent. Plasticizers and superplasticizers retard the curing of concrete.
Air entrainment is the intentional creation of tiny air bubbles in concrete. A concrete maker introduces the bubbles by adding to the mix an air entraining agent, a surfactant. The air bubbles are created during mixing of the plastic concrete, and most of them survive to be part of the hardened concrete. The primary purpose of air entrainment is to increase the durability of the hardened concrete, especially in climates subject to freeze-thaw; the secondary purpose is to increase workability of the concrete while in a plastic state in concrete.
Lime mortar is composed of lime and an aggregate such as sand, mixed with water. The Ancient Egyptians were the first to use lime mortars. About 6,000 years ago, they used lime to plaster the pyramids at Giza. In addition, the Egyptians also incorporated various limes into their religious temples as well as their homes. Indian traditional structures built with lime mortar, which are more than 4,000 years old like Mohenjo-daro is still a heritage monument of Indus valley civilization in Pakistan. It is one of the oldest known types of mortar also used in ancient Rome and Greece, when it largely replaced the clay and gypsum mortars common to ancient Egyptian construction.
The water–cement ratio is the ratio of the weight of water to the weight of cement used in a concrete mix. A lower ratio leads to higher strength and durability, but may make the mix difficult to work with and form. Workability can be resolved with the use of plasticizers or super-plasticizers.
Cement rendering is the application of a premixed layer of sand and cement to brick, concrete, stone, or mud brick. It is often textured, colored, or painted after application. It is generally used on exterior walls but can be used to feature an interior wall.
Concrete is produced in a variety of compositions, finishes and performance characteristics to meet a wide range of needs.
Concrete has relatively high compressive strength, but significantly lower tensile strength. The compressive strength is typically controlled with the ratio of water to cement when forming the concrete, and tensile strength is increased by additives, typically steel, to create reinforced concrete. In other words we can say concrete is made up of sand ,balast, cement and water.
Epoxy moisture control systems are chemical barriers that are used to prevent moisture damage to flooring. Excessive moisture vapor emissions in concrete slabs can mean significant, expensive damage to a flooring installation. Hundreds of millions of dollars are spent annually just in the United States to correct moisture-related problems in flooring. These problems include failure of the flooring adhesive; damage to the floor covering itself, such as blistering; the formation of efflorescence salts; and the growth of mold and mildew.
Self-leveling concrete is polymer-modified cement that has high flow characteristics and, in contrast to traditional concrete, does not require the addition of excessive amounts of water for placement. Self-leveling concrete is typically used to create a flat and smooth surface with a compressive strength similar to or higher than that of traditional concrete prior to installing interior floor coverings. Self-leveling concrete has increased in popularity as the degree of flatness and smoothness required for floor covering products has increased, with vinyl goods becoming thinner and floor tiles becoming larger, for example.
A traditional method for the installation of tile and stone.
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