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New highly effective reduces the water medicinal preparation synopsis The modern construction projects and the engineering structure and itsthe construction technology more and more many more and more is alsohigh to the concrete request, not only the request suitably hasresistant to compression, the anti - booklet, the anti-pulls, the anti-curved intensity, moreover must as desired have Gao Kangdong, impermeability the natural, corrosion-resisting, the anti-alkali - aggregatereactivity, compactness and the durability, to can resist each kind tocome from the internal or exterior factor destruction, and must havethe appropriate fluidity and take shape and the hydrated performance, satisfies each kind of construction environment and the constructioncondition request. Thus in the concrete preparation process, usuallyfront must mixes in it gathers in the thing or mixes gathers mixesinto is not bigger than the cement weight certain proportion (usuallyis 5% ) the sur-medicinal preparation, by time change or improvementconcrete performance such as fluidity, workability and early strength, the anti-frozen, impermeability natural, hydrated advancement and so on. In the21st century, excels in, the high performance and the high durableconcrete development and the application is in particular cannot leaveeach kind of highly effective sur-medicinal preparation use. In orderto satisfy and adapts these requests, the various countries concretematerial expert has conducted the massive research, the developmentand the application, unceasingly develops each kind of sur-medicinalpreparation and its the compound application, caused the concrete theperformance improvement to obtain the tangible result。Superplasticizer was in the 1960s developed a water-reducing agent. In1963, the Federal Republic of Germany successfully developed melamineformaldehyde condensation of sulfonate, at the same time there werePAHs sulfonate formaldehyde condensate. Since these three have strongadmixture of the scattered cement capacity, reduce water rates as highas 20% to 30%, while different from those of ordinary plastics (waterreducer), which called superplasticizer or superplasticizer agent.Superplasticizer to the sexual revolution has brought concretechanges, promoting high-strength concrete, flowing concrete mixingconcentrated goods and the development of concrete, has been widelyused self-leveling mortar and concrete preparation, concreteunderwater watering, No macroscopic defects Concrete andhigh-performance concrete. Accompanied by a high-intensity, highmobility of the technical development of concrete, concrete admixturehas quickly developed. The first is to develop Naphthalene, denseamine of superplasticizer, in recent years polycarboxylic acid to thesuperiority of superplasticizer has received widespread internationalacceptance and widespread use. In concrete incorporationsuperplasticizer, many properties such as micro-structure, porosity,adsorption, hardening speed, intensity and so on will be changed, thehydration of cement and cement itself mineral some properties will beaffected. New high-performance water-reducing agent is HPC technologydevelopment at home and abroad an important aspect |
