Engineers in the early 20th century believed that reinforced concrete structures would endure for centuries, perhaps even up to 1,000 years. In reality, however, their lifespan is more like 50 to 100 years, and sometimes even less. Building codes and policies often require buildings to last for several decades, but deterioration can begin in as little as 10 years. The design life of most buildings is typically 30 years, although they often last 50-100 years or more. Because of their durability, most concrete and masonry buildings are demolished due to functional obsolescence rather than deterioration.
However, a concrete frame or structure can be reused if the use or function of the building changes or when the interior of the building is renovated. Concrete, both as a structural material and as the outer skin of the building, has the ability to withstand the normal deterioration mechanisms of nature, as well as natural disasters. Concrete made with low permeability sand usually results in durable structures. Most buildings last between 50 and 100 years. Concrete and masonry buildings are demolished because of functional obsolescence rather than deterioration.
But a concrete structure is reused when the interior of a building is renovated. In addition to using concrete with low permeability, surface treatments can be used to prevent aggressive substances from coming into contact with the concrete. In larger projects, such as buildings and houses, concrete should last between 30 and 100 years or more, depending on the style of construction and method of installation. Different concretes require different degrees of durability depending on the exposure environment and desired properties. Air-charged concrete, with a low water-cement ratio and an air content of 5 to 8 per cent of properly distributed air voids, will withstand a large number of freeze-thaw cycles without suffering. In addition to construction materials and design, the longevity of a concrete building also depends on the foundation.
Concrete cannot last forever, but it can last for decades if properly mixed, installed and cared for. If you notice cracks or breaks in the concrete over the years, concrete experts can repair it. You can even consult a professional to inspect your concrete project over the years to ensure that no changes or reinforcements are necessary. If you live in a location that experiences extreme temperatures, the service life of your concrete will be significantly less than in a more temperate environment. The Specifier's Guide to Durable Concrete (EB221) and Concrete Mix Design and Control (EB001) provide sufficient information to enable practitioners to select materials and mix design parameters to achieve durable concrete in a variety of environments.
Reinforced concrete competes with more durable construction technologies such as steel frame or traditional bricks and mortar. The high pH environment of concrete (typically above 12) causes a passive protective oxide film to form on the steel. Muzenski admits that this new technology is not ideal for all situations: some concrete applications require more flow for construction, and the curved fibres reduce flow. The new material, dubbed superhydrophobic cementitious composite, is also more malleable than traditional concrete. But more than a thousand years after the Western Roman Empire turned to dust, its concrete structures are still standing. When using concrete in a domestic project, it is important to consider certain factors to determine its durability and lifespan.
These include selecting low permeability sand for mixing; using surface treatments to prevent aggressive substances from coming into contact with the material; ensuring proper installation; inspecting regularly; and taking into account environmental conditions such as extreme temperatures.
