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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]
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A single concrete block, as used for construction. Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to a solid over time. . Concrete is the second-most-used substance in the world after water, [1] and is the most widely used building material
Concretene is a graphene-enhanced admixture for concrete [1] [2] that delivers savings on cost and CO 2 emissions. The formulation has been developed by Nationwide Engineering Research & Development (NERD) in collaboration with The University of Manchester 's Graphene Engineering Innovation Centre (GEIC).
Their addition allows to decrease the water-to-cement ratio of concrete or mortar without negatively affecting the workability of the mixture. It enables the production of self-consolidating concrete and high-performance concrete. The water–cement ratio is the main factor determining the concrete strength and its durability. Superplasticizers ...
2 emissions, of which 60% is from the chemical process, and 40% from burning fuel. [67] A Chatham House study from 2018 estimates that the 4 billion tonnes of cement produced annually account for 8% of worldwide CO 2 emissions. [4] Nearly 900 kg of CO 2 are emitted for every 1000 kg of Portland cement produced. In the European Union, the ...
Researchers have tried to sequester CO 2 in concrete by developing advanced materials. One approach is to use magnesium silicate as an alternative to calcium. This lowers the temperature required for the production process and decreases the release of carbon dioxide during firing. During the hardening phase, additional carbon is sequestered.
H 2 O → H + + OH (hydroxyl radical) + e − O 2 + e − → O 2 − (a superoxide ion) The overall reaction is therefore: H 2 O + O 2 → H + + O 2 − + OH. The hydroxyl radical is a powerful oxidizing agent and can oxidize nitrogen dioxide to nitrate ions: NO 2 + OH → H + + NO 3 −. The superoxide ion is also able to form nitrate ions ...