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以不同数量的粉煤灰和不同的粉煤灰与水泥比,混凝土抗压强度为20Mp 和55Mp,对混凝土的徐变,收缩和弹性模量的影响并在相同的工作度的情况下与普通混凝土在三天或二十八天期令相比较。与普通混凝土相比较结果表明,混凝土中应用质量较好的粉煤灰具有相同的弹性模量和显著低的徐变与收缩,当应用中等质量的粉煤灰,以上各性均匀与普通混凝土相等。粉煤灰成功地作为火山灰应用在大坝工程与大体积混凝土结构中已有许多年,最初是为了降低价格与控制水化热,另外有的加入粉煤灰为的更有益于降低混凝土渗透性和增加抗硫酸盐侵蚀性能,近期结构混凝土要求混凝土强度达到55Mpa 和更高,为达到这个要求,推广应用粉煤灰(这成为另一个理由。)混凝土强度降低的程度可采用掺加粉煤灰利用其对混凝土有益的影响使之产生高强。确实,这种火山灰质材料已作为生产高强混凝土的基本混合材。混凝土掺加粉煤灰要达到 fc’强度令期要超过28天,由于缺乏应用粉煤灰混凝土的徐变资料,因此着手进行粉煤灰对混凝土的徐变,收缩和弹性模量影响的试验以补其资料之不足。
With different amounts of fly ash and different fly ash to cement ratios, the compressive strength of the concrete is 20 Mp and 55 Mp. The effect on the creep, shrinkage and elastic modulus of the concrete is similar to that of ordinary concrete under the same working degree. The concrete was compared on three days or twenty-eight days. Compared with ordinary concrete, the results show that fly ash with better quality in concrete has the same elastic modulus and significantly lower creep and shrinkage. When medium-quality fly ash is used, the above properties are equal to ordinary concrete. . Fly ash has been successfully used as a volcanic ash in dam projects and mass concrete structures for many years, initially to reduce the price and control of heat of hydration, and some additions of fly ash are more beneficial to reduce the permeability of concrete. And to increase the resistance to sulfate attack, the recent structural concrete requires the concrete strength to reach 55 Mpa and higher. In order to meet this requirement, the use of fly ash is promoted (this is another reason.) The degree of concrete strength reduction can be added with fly ash Use its beneficial effects on concrete to make it strong. Indeed, this pozzolanic material has been used as a basic blend of high-strength concrete. The addition of fly ash to concrete requires fc’ strength to exceed 28 days. Due to the lack of creep data for fly ash concrete, experiments on creep, shrinkage and modulus of elasticity of fly ash are conducted. To make up for the lack of information.