昌吉-古泉±1100kV特高压直流输电线路甘肃段基础混凝土耐久性试验研究

Experimental study on durability of foundation concrete in changji-guquan 1100kv uhc dc transmission project in gansu province

为研究多种因素作用下输电线路基础混凝土的耐久性变化规律,通过电通量法、快速冻融法和硫酸盐干湿循环腐蚀,测试了不同混凝土的抗氯离子渗透性、抗冻性和抗硫酸盐腐蚀性。试验结果表明:水胶比越大的混凝土,其抗氯离子渗透性越差,随着龄期的增长,混凝土抗氯离子渗透性有一定的提高,且提高幅度与粉煤灰掺量正相关;C30混凝土在冻融循环过程中,发生酥松破坏,抗冻等级仅能达到F150,其余混凝土抗冻等级能达到F200,且破坏程度随着混凝土强度的提高而降低;在硫酸盐干湿循环作用下,不同强度等级的混凝土的抗压强度都遵循着先提高后降低的趋势。但强度转变所对应的干湿循环次数不同,强度等级越高的混凝土出现的越晚。

In order to study the durability of foundation concrete under the influence of many factors, the chloride ion permeability, frost resistance and corrosion resistance of different concrete were tested by means of electric flux method, rapid freezethaw method and cyclic corrosion of sulfate wet and dry Anti-sulfate corrosive. The experimental results show that the concrete with higher water-cement ratio has a lower resistance to chloride ion penetration. As the age increases, the chloride resistance of concrete increases to a certain extent, and the increase rate is positively correlated with the fly ash content. In the process of freeze-thaw cycle, C30 concrete is damaged by crisp, the frost resistance level can only reach F150, the other concrete can reach F200, and the damage degree decreases with the increase of concrete strength. Under the different strength levels of concrete compressive strength follow the first increase and then reduce the trend. However, the intensity change corresponding to the number of different wet and dry cycles, the higher the intensity level of concrete appears later.