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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.
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
High-pressure chemistry is concerned with those chemical processes that are carried out under high pressure – pressures in the thousands of bars (100 kPa) or higher. High-pressure processes are generally faster and have a higher conversion efficiency than processes at ambient pressure.
In greater detail, the benefits of pozzolanic concrete, starts with an understanding that in concrete (including concretes with EMCs), Portland cement combines with water to produce a stone-like material through a complex series of chemical reactions, whose mechanisms are still not fully understood.
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]
Pressure grouting or jet grouting [1] involves injecting a grout material into otherwise inaccessible but interconnected pore or void space of which neither the configuration or volume are known, and is often referred to simply as grouting. The grout may be a cementitious, resinous, or solution chemical mixture. Some types of injected grout may ...
A high proportion of damp problems in buildings are caused by ambient climate dependent factors of condensation and rain penetration. [1] Capillary penetration of fluid from the ground up through concrete or masonry is known as "rising damp" and is governed by the shape and porosity of the construction materials through which this evaporation ...
Urea plant using ammonium carbamate briquettes, Fixed Nitrogen Research Laboratory, ca. 1930 Carl Bosch, 1927. The Bosch–Meiser process is an industrial process, which was patented in 1922 [1] and named after its discoverers, the German chemists Carl Bosch and Wilhelm Meiser [2] for the large-scale manufacturing of urea, a valuable nitrogenous chemical.