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Sulfates in solution in contact with concrete can cause chemical changes to the cement, which can cause significant microstructural effects leading to the weakening of the cement binder (chemical sulfate attack). Sulfate solutions can also cause damage to porous cementitious materials through crystallization and recrystallization (salt attack). [7]
Concrete used for canal lining is typically non-reinforced, as a way to reduce cost. A common method for constructing concrete lining is the use of slip forms, which are drawn down the length of the canal as the concrete is poured. [3] Hand laying of concrete or prefabricated sections are also used when only a short distance needs to be covered ...
This is because channellizing the flow in a concrete chute often made flooding worse. [43] [44] [45] Really bad floods are caused by really brief spikes of river level. Channellization in concrete chutes speeds the water up and makes the flood peak higher, while slowing the water down spreads the flow out over time and blunts the flood peak.
Concrete is used to create hard surfaces which contribute to surface runoff that may cause soil erosion, water pollution and flooding. Conversely, concrete is one of the most powerful tools for proper flood control, by means of damming, diversion, and deflection of flood waters, mud
Frost damage of early-age concrete is particularly harmful for the concrete mechanical resistance because the ice volume expansion causes micro-cracks in the concrete structures, and as a consequence it lowers the compressive strength of concrete. [4]
When it reacts with concrete, it causes the slab to expand, lifting, distorting and cracking as well as exerting a pressure onto the surrounding walls which can cause movements significantly weakening the structure. Some infill materials frequently encountered in building fondations and causing sulfate attack are the following: [2] Red Ash
This may cause the following issues: rising water tables; increased storage of groundwater that may be used for irrigation, municipal, household, and drinking water by pumping from wells; waterlogging and drainage problems in villages, agricultural lands, and along roads - with mostly negative consequences. The increased level of the water ...
To attempt to simplify and to stylize a very complex set of various reactions, the whole ASR reaction, after its complete evolution (ageing process) in the presence of sufficient Ca 2+ cations available in solution, could be compared to the pozzolanic reaction which would be catalysed by the undesirable presence of excessive concentrations of alkali hydroxides (NaOH and KOH) in the concrete.