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谈谈“消泡”有些种类的减水剂掺入混凝土后,要产生大量气泡,这对混凝土强度的发展不利。一般认为:混凝土含气量每增加1%,使其强度下降约5%,因此,在需要保证强度的部位,选择使用含气量增加较少或无加气性的减水剂,或者复合使用消泡剂是有必要的。国内常用的消泡剂,如 SP-169、磷酸三丁脂、有机硅油等。由于这些消泡剂能改变水泥浆与气泡的界面张力,使气泡(尤其是大气泡)失去稳定而破裂,于是含气量降低,混凝土强度得到正常发展。消泡剂用量都很小,对混凝土的其他性能没有大的影响。搅拌和振捣对含气量也有不小的影响,
Talk about “defoaming” Some types of superplasticizer mixed with concrete, to produce a large number of bubbles, which is not conducive to the development of concrete strength. Generally believed that: for every 1% increase in air content of concrete, so that the intensity decreased by about 5%, therefore, in the need to ensure the strength of the site, choose to use less gas content or non-aerated water reducing agent, or defoamer Agents are necessary. Domestic defoamers commonly used, such as SP-169, tributyl phosphate, silicone oil and so on. Because these defoamers can change the interfacial tension between the cement slurry and the bubble, the bubble (especially the large bubble) loses its stability and ruptures, so the gas content is reduced and the concrete strength is normally developed. The amount of defoamers are very small, the other properties of concrete do not have a big impact. Stirring and vibration on the gas content is also not a small impact,