To make concrete, a mixture of portland cement (10-15%) and water (15-20%) make a paste. This paste is then mixed with aggregates (65-75%) such as sand and gravel, or crushed stone. As cement and water mix, they harden and bind the aggregates into an impenetrable rock-like mass. The manufacture of concrete is quite simple.
First, cement is prepared (usually Portland cement). Then, the other added ingredients (such as sand or gravel), additives (chemical additives), any necessary fibers and water are mixed with the cement to form the concrete. Then the concrete is sent to the work site and laid, compacted and cured. The most common way to manufacture portland cement is by a dry method.
The first step is to extract the main raw materials, mainly limestone, clay and other materials. After extraction, the rock is crushed. The first crushing reduces the rock to a maximum size of approximately 6 inches. The rock then goes to secondary crushers or hammer mills to reduce it to about 3 inches or less.
Portland Island While cement in one form or another has existed for centuries, the type we use was invented in 1824 in Great Britain. It was called portland cement because it looked like stone mined on the island of Portland. Aggregates are coarse materials such as gravel, sand or crushed bricks that are added to cement and water. Cement is attached to them, keeping them in place.
Although aggregates are often thought of as a filler, they are actually a key component of concrete. Between 60 and 80 percent of concrete is made of aggregates. Concrete floors were found in the royal palace in Tiryns, Greece, which dates from approximately 1400 to 1200 BC. Concrete is expected to be a key material for structures resistant to climatic disasters, as well as a solution to mitigate pollution from other industries, capturing debris such as coal fly ash or bauxite residues and residues.
Concrete mix specifications generally set limits for chlorides, sulfates, alkalis, and solids in the mixing water, unless tests can be performed to determine the effect the impurity has on the final concrete. If you're considering using concrete for a construction project, knowing more about how concrete works can help you choose the right mix for your project. The adjacent image shows one of many ways to achieve this, submerge the concrete in water and wrap it in plastic to prevent dehydration. The manufacture and use of concrete produces a wide range of environmental, economic and social impacts.
Reinforced concrete, prestressed concrete and precast concrete are the most widely used types of functional concrete extensions today. Concrete is used to create hard surfaces that contribute to surface runoff, which can cause strong soil erosion, water pollution and flooding, but, on the contrary, it can be used to divert, dam and control flooding. During the preparation of concrete, various technical details may affect the quality and nature of the product. Simple non-reinforced concrete is not suitable for many structures, as it is relatively poor in withstanding stresses induced by vibrations, wind load, etc.
However, considering the purpose of having a circularity of resources in the life cycle of concrete, the only application of RCA that could be considered as recycling concrete is the replacement of natural aggregates in concrete mixes. While concrete is itself a building material, mortar is a bonding agent that normally holds bricks, tiles and other masonry units together. Fresh concrete (before curing is complete) is highly alkaline and must be handled with appropriate protective equipment. Small-scale production of concrete-like materials was started by Nabataean merchants who occupied and controlled a series of oases and developed a small empire in the southern regions of Syria and northern Jordan beginning in the 4th century BC.
Recycling or reclaiming concrete reduces exploitation of natural resources and associated transportation costs, and reduces landfills.