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A cement accelerator is an admixture for the use in concrete, mortar, rendering or screeds. The addition of an accelerator speeds the setting time and thus cure time starts earlier. [ 1 ] This allows concrete to be placed in winter with reduced risk of frost damage. [ 2 ]
Accelerated curing is any method by which high early age strength is achieved in concrete. These techniques are especially useful in the prefabrication industry, wherein high early age strength enables the removal of the formwork within 24 hours, thereby reducing the cycle time, resulting in cost-saving benefits. [ 1 ]
In other words, it is added to the concrete mixture itself when the concrete is laid. The usual dosage is two to three percent of the concrete mixture. Because water is a part of the batching process, an additional curing process is not required. This approach is easier and less labor-intensive, but it can only be used when new concrete is laid.
Likewise, it is used to calculate lipophilic efficiency in evaluating the quality of research compounds, where the efficiency for a compound is defined as its potency, via measured values of pIC 50 or pEC 50, minus its value of log P. [27] Drug permeability in brain capillaries (y axis) as a function of partition coefficient (x axis) [28]
Curing is a chemical process employed in polymer chemistry and process engineering that produces the toughening or hardening of a polymer material by cross-linking of polymer chains. [1] Even if it is strongly associated with the production of thermosetting polymers , the term "curing" can be used for all the processes where a solid product is ...
On the other hand, for completely dry concrete, the chemical reaction of carbonation cannot occur. Another influencing factor for CO 2 diffusion rate is concrete porosity. Concrete obtained with higher w/c ratio or obtained with an incorrect curing process presents higher porosity at hardened state, and is therefore subjected to a higher ...
Oxidation of pyrite in clay formations in contact with concrete – this produces sulfuric acid which reacts with concrete. Bacterial activity in sewers – anaerobic sulfate reduction at work in the organic-rich sludges accumulated under water in the conduits produces hydrogen sulfide gas (H 2 S).
pK a of acetic acid in dioxane/water mixtures. Data at 25 °C from Pine et al. [45] When a compound has limited solubility in water it is common practice (in the pharmaceutical industry, for example) to determine pK a values in a solvent mixture such as water/dioxane or water/methanol, in which the compound is more soluble. [46]