【作者】 郭亮；

【导师】 李家和；

【作者基本信息】 哈尔滨工业大学 ， 材料学， 2010， 硕士

【摘要】 混凝土的渗透性是影响混凝土耐久性的最重要因素之一。本文主要研究了矿物掺合料对混凝土的抗压强度、氯离子电通量和氯离子扩散系数的影响;自主设计加工了一种测试混凝土气体渗透系数的试验装置,并研究了施加于混凝土试件的气体压力、流量,矿物掺合料以及冻融循环次数对混凝土气体渗透系数的影响。研究结果表明:保持水泥用量一定时,增加用水量,混凝土的强度下降,氯离子电通量和氯离子扩散系数增大;掺入粉煤灰后,混凝土的28d强度下降,氯离子电通量的改善作用不明显,氯离子扩散系数降低,粉煤灰掺量20%时,C30混凝土的60d氯离子扩散系数比掺量为10%的混凝土的大,但仍低于基准混凝土;掺入矿渣粉和硅灰,混凝土的28d强度提高,氯离子电通量和氯离子扩散系数降低程度较大。加工的带数据采集系统的气体渗透试验装置很好的解决了以往测试装置未有数据自动采集系统的问题。研究发现,气体压力及流量对混凝土气体渗透系数的测试结果产生较大的影响,它们与气体渗透系数的关系并不是单纯的正比和反比关系。掺入粉煤灰后,混凝土的气体渗透系数降低,但掺量20%时,C30混凝土的60d气体渗透系数比掺量为10%时大6.2%;掺入矿渣和硅灰,混凝土的气体渗透系数降低幅度较大。混凝土经冻融循环后,气体渗透系数增加,并且冻融循环次数越多,混凝土的气体渗透系数越大,其中冻融80次时,C60和C30混凝土的气体渗透系数分别增加了16.5%和49.0%。更多还原

【Abstract】 Permeability is one of the most important factors which influenced the durability of concrete. In this paper, compressive strength, chloride permeability of concrete with mineral admixtures were experimentally investigated. A experimental arrangement for testing gas permeability coefficient of concrete was designed and processed independently, and investigated the influence of gas pressure imposed on the concrete sample, gas flow rate, mineral admixtures and freeze-thaw cycle on gas permeability coefficient of concrete.Test results showed that increased water-cemenet ratio, compressive strength of concrete declined, the charge passed the concrete and chloride diffusion coefficient increased. The incorporation of fly ash can let compressive strength and chloride diffusion coefficient of concrete down, but the improvement of the charge is not very significant. When the mass percent of fly ash was 20%, the 60d charge and chloride diffusion coefficient of C30 concrete are bigger than the ones when the mass percent of fly ash was 10%, but they were lower than basic concrete. The incorporation of ground slag or silica fume can increase the 28d strength, and let the charge and chloride diffusion coefficient decline significantly.An experimental arrangement with data processing system for the test of the gas permeability coefficient of concrete was processed. The study shows gas pressure and flow influenced the test result of gas permeability coefficient clearly, the relationship between them and gas permeability coefficient is not simple proportional or inverse relationship. The incorporation of fly ash can let gas permeability coefficient of concrete down. When the mass percent of fly ash was 20%, the 60d gas permeability coefficient was 6.2 percent bigger than the ones when the mass percent of fly ash was 10%. The incorporation of ground slag or silica fume can decline gas permeability coefficient significantly. After freezing and thawing action, gas permeability coefficient of concrete increased with the frequency of freeze-thaw cycle. When the frequency of freeze-thaw cycle is 80, the gas permeability coefficient of C60 and C30 concreterose by 16.5 percent and 49.0 percent respectively.更多还原