Ads
related to: concrete problems spallingdoconsumer.com has been visited by 10K+ users in the past month
Search results
Results from the WOW.Com Content Network
If concrete is exposed to very high temperatures very rapidly, explosive spalling of the concrete can result. In a very hot, very quick fire the water inside the concrete will boil before it evaporates. The steam inside the concrete exerts expansive pressure and can initiate and forcibly expel a spall. [23]
ASR can lead to serious cracking in concrete, resulting in critical structural problems that can even force the demolition of a particular structure. [4] [5] [6] The expansion of concrete through reaction between cement and aggregates was first studied by Thomas E. Stanton in California during the 1930s with his founding publication in 1940. [7]
Oxide jacking has caused concrete spalling on walls of the Herbst Pavilion at Fort Mason Center in San Francisco. The expansive force of rusting, which may be called oxide jacking or rust burst, is a phenomenon that can cause damage to structures made of stone, masonry, concrete or ceramics, and reinforced with metal components.
Explosive spalling events of refractory concrete can result in serious problems. If an explosive spalling occurs, projectiles of reasonable mass (1–10 kg) can be thrust violently over many metres, which will have safety implications and render the refractory structure unfit for service.
Alkali–aggregate reaction is a term mainly referring to a reaction which occurs over time in concrete between the highly alkaline cement paste and non-crystalline silicon dioxide, which is found in many common aggregates. This reaction can cause the expansion of the altered aggregate, leading to spalling and loss of strength of concrete.
A fairly well-defined reaction front can often be observed in thin sections; ahead of the front the concrete is normal, or near normal. Behind the reaction front, the composition and the microstructure of concrete are modified. These changes may vary in type or severity but commonly include: Extensive cracking; Expansion
For ordinary Portland cement, it reacts with the calcium hydroxide in concrete to form calcium sulfate. This change simultaneously destroys the polymeric nature of calcium hydroxide and substitutes a larger molecule into the matrix causing pressure and spalling of the adjacent concrete and aggregate particles. [7]
Concrete spalling from the ceiling of an office unit (interior) in Singapore, possibly due to rebar corrosion. Reinforced concrete can fail due to inadequate strength, leading to mechanical failure, or due to a reduction in its durability. Corrosion and freeze/thaw cycles may damage poorly designed or constructed reinforced concrete.
Ads
related to: concrete problems spallingdoconsumer.com has been visited by 10K+ users in the past month