矿物掺合料混凝土保护层锈胀开裂条件的试验研究.doc

矿物掺合料混凝土保护层锈胀开裂条件的试验研究 【中文摘要】当混凝土结构处于比较恶劣的环境条件,混凝土内钢筋会不断锈蚀导致混凝土保护层锈胀开裂,特别是海港工程混凝土结构长期受到氯离子腐蚀和干湿交替变化影响,因此海港工程混凝土结构钢筋锈蚀速度比普通混凝土结构的快得多,钢筋腐蚀破坏造成的直接、间接损失更大。因此,如何在设计、建造期引用适当的方法,确保建筑物达到预期的使用寿命已成为国内外工程界极为关注的热门题目。本文以海港工程混凝土结构为对象,围绕影响矿物掺合料混凝土中钢筋锈蚀的因素、矿物掺合料混凝土保护层锈胀开裂条件以及锈胀裂缝形态等内容展开,通过理论分析与试验研究相结合,对矿物掺合料混凝土保护层锈胀开裂的影响因素进行了分析。研究结果表明随着水胶比、单掺粉煤灰的掺量及保护层厚度与钢筋直径比值的增加,矿物掺合料混凝土保护层锈胀开裂时钢筋锈蚀率也相应增大,而随着矿渣及硅灰掺量的增加,钢筋锈蚀率会减小。通过对试验数据进行非线性回回,建立了考虑水胶比、矿物掺合料的种类及掺量、保护层厚度与钢筋直径比值c/d、钢筋位置及钢筋种类等因素的矿物掺合料混凝土保护层锈胀开裂条件的计算模型,通过对模型计算值与实测值的比较分析,表明该模型具有较好的适用性。; 【Abstract】 When the concrete structure in a relatively poor environmental conditions,concrete reinforcement corrosion will lead to concrete cracking corrosive protective coating,in particular long-term concrete structure works in marine concrete structures by the chloride ion erosion and alternating wet and dry change of reinforced su***ce,so the concrete in marine concrete structures structure works faster than normal concrete structure,Damage caused by steel corrosion direct and indirect losses is much larger. therefore,how in the design,construction s appropriate to quote to ensure that the service life of buildings to achieve the desired engineering has become a hot issue of great concern.In this ***,to study the marine concrete structure,around the mineral admixture mechanism of steel corrosion in concrete,the impact of mineral admixture concrete protective layer corrosive conditions and corrosive cracking patterns such as cracking start,through the theoretical analysis and experimental study of the combination of mineral admixture corrosive protective layer of concrete cracking analysis of influencing factors.The results show thatWith the water-to-binderw/b ratio,the fly ash content and the cover-to-diameterc/d ratio increases,concrete mineral admixture corrosive protective coating steel corrosion rate when the crack will also increase accordingly,with slag and silica fume content increases,reducing the rate of steel corrosion,a model to calculate the ratio of corrosion which taking into account of the factors above was proposed by non-linear regression according to the test data.The results calculated by the ula agree well with of the measured results.