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Study of modifications of latex-modified concrete system.

机译：乳胶改性混凝土体系的改性研究。

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摘要

The major impetus of this study was the indication in 1986 that latex-modified concrete for highway bridge deck overlays would not be exempt from Federal requirements that mandate the use of fly ash in concrete at the contractor's option. Since there had been essentially no engineering evaluation or controlled research on the effects of fly ashes on such concretes, an early indication of any potential deleterious effects was imperative.;Tests were performed to determine the effects on chloride permeability, freezing-thawing resistance, strength, bond, and dynamic modulus of elasticity of latex-modified concretes resulting from incorporation of fly ash. In addition, pore size distribution and microstructure were studied on latex-modified cement pastes containing fly ash. Four different representative fly ashes of both Class F and Class C types were used in this study at replacement levels of 15% and 25% by weight of cement.;The results indicated that not only did fly ash not degrade the overall performance characteristics of ordinary latex-modified concrete, its inclusion significantly improved chloride permeability and generally improved cement paste pore structure and bond to underlying concrete.;A method was developed to permit visualization of the three dimensional latex network on scanning electron microscopy. It was found that fly ash affects this network. The network is somewhat more dense with fly ash, and individual fly ash particles are anchored to the network.;Investigations were also conducted on possible modifications of latex-modified concrete incorporating various combinations of latex, superplasticizer, and silica fume. It was found that incorporation of superplasticizer improved the properties of the latex-modified concrete significantly; that satisfactory latex-modified concrete could be produced with reduced latex contents, thus providing significant materials cost savings; and that latex-modified concretes with silica fume and superplasticizer were not uniformly superior to ordinary latex-modified concretes, problems with stickiness and paste pore structure being observed.
机译：这项研究的主要动力是在1986年表明，高速公路桥梁桥面覆盖物的乳胶改性混凝土将不受联邦政府的要求，后者要求承包商选择使用粉煤灰。由于基本上没有关于粉煤灰对此类混凝土的影响的工程评估或对照研究，因此必须尽早表明任何潜在的有害影响。进行测试以确定对氯化物渗透性，抗冻融性，强度的影响掺入粉煤灰的乳胶改性混凝土的粘度，粘结力和动态弹性模量。此外，还研究了含粉煤灰的乳胶改性水泥浆的孔径分布和微观结构。本研究中使用了F级和C级两种粉煤灰的四种不同代表性粉煤灰，其替代含量分别为水泥重量的15％和25％.;结果表明，粉煤灰不仅不会降低普通水泥的总体性能特征胶乳改性的混凝土，其包含物显着提高了氯化物的渗透性，并总体上改善了水泥浆的孔隙结构和与基础混凝土的粘结性。开发了一种方法，可以在扫描电子显微镜下可视化三维胶乳网络。发现粉煤灰会影响该网络。网络中粉煤灰的密度更高，并且单个粉煤灰颗粒固定在网络中。还对掺入了各种胶乳，高效减水剂和硅粉的胶乳改性混凝土进行了可能的改性研究。发现掺入高效减水剂可以显着改善乳胶改性混凝土的性能。可以降低乳胶含量生产出令人满意的乳胶改性混凝土，从而大大节省了材料成本；并且具有硅粉和高效减水剂的胶乳改性混凝土不能均匀地优于普通胶乳改性混凝土，存在粘性和糊孔结构的问题。

著录项

  • 作者

    Sheng, Qizhong.;

  • 作者单位

    Purdue University.;

  • 授予单位 Purdue University.;
  • 学科 Engineering Civil.;Engineering Materials Science.
  • 学位 Ph.D.
  • 年度 1990
  • 页码 233 p.
  • 总页数 233
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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