变电站基础C40混凝土抗硫酸盐侵蚀防泛碱试验研究

Experimental Study on Sulfate Corrosion Resistance and Anti Efflorescence of C40 Concrete for Substation Foundation

山西地区变电站基础混凝土常产生泛碱现象,严重影响外观和耐久性。经调查,所处环境中广泛存在着SO_(4)^(2-)侵蚀性介质,兼顾抗硫酸盐侵蚀与防泛碱,开展了复合掺合料抗硫酸盐侵蚀及防泛碱性能试验研究,配制出C40混凝土抗硫酸盐侵蚀防泛碱混凝土,经试验研究得到如下结论:(1)复合掺合料可提高混凝土的抗硫酸盐侵蚀能力;(2)4组配合比中,抗硫酸侵蚀性能总的趋势为传统水泥混凝土<双掺复合掺合料混凝<三掺复合掺合料混凝土<高性能混凝土;(3)所配制的高性能混凝土抗硫酸盐侵蚀能力及防泛碱性能得到提高,但强度有所降低;(4)混凝土抗硫酸盐侵蚀能力提高的同时,抗碳化能力也得到提高。

Efflorescence phenomenon often occurs in the foundation concrete of substations in Shanxi,which se⁃riously affects the appearance and durability.Through investigation,SO_(4)^(2-)aggressive medium widely exists in the environment.Giving consideration to sulfate corrosion resistance and anti efflorescence,experimental study on sulfate corrosion resistance and anti efflorescence performance of composite admixtures is carried out,and C40 concrete with sulfate corrosion resistance and anti efflorescence is prepared.The following conclusions are drawn through experimental study:(1)Composite admixtures can improve the sulfate corrosion resistance of concrete;(2)In the four groups of mix proportions,the general trend of sulfate corrosion resistance and anti ef⁃florescence is:traditional cement concrete<double mixed composite admixture concrete<three mixed compos⁃ite admixture concrete<high performance concrete(HPC);(3)The HPC prepared has improved its sulfate cor⁃rosion resistance and anti alkali performance,but its strength has decreased;(4)With the improvement of sul⁃fate resistance,the carbonation resistance of concrete is also improved.