玻璃粉/硅粉复掺对混凝土腐蚀环境下耐久性的影响

基于格尔木地区土壤中实测腐蚀性离子种类与含量,设计Na₂CO₃、NaCl、Na₂SO₄及MgSO₄复合溶液进行全浸泡试验,通过相对质量评价参数(ω₁)与相对动弹性模量评价参数(ω₂)变化规律研究玻璃粉/硅粉复掺对混凝土耐久性能的影响.分析标准养护下玻璃粉/硅粉复掺对胶凝材料水化反应的影响,以及玻璃粉/硅粉复掺混凝土受复合盐溶液侵蚀的微观机理.并依据Wiener理论预测了复合盐溶液腐蚀环境下混凝土的服役寿命.结果表明:复合盐溶液腐蚀环境下,混凝土劣化幅度因玻璃粉掺量的变化而不同;标准养护下玻璃粉/硅粉复掺对胶凝材料水化产物无影响,且养护至56~120 d时SiO₂仍进行着明显的火山灰效应;玻璃粉掺量10%、硅灰掺量6%时,玻璃粉/硅粉复掺对混凝土气孔结构有所改善,所以在复合盐溶液腐蚀前后混凝土内部平均气泡孔径均小于未掺玻璃粉与硅灰时的混凝土气泡孔径;玻璃粉/硅粉复掺制备混凝土时玻璃粉掺量不宜超过10%.

Effect of glass powder/silica fume mixture on durability of concrete under corrosive environment

Based on the species and contents of corrosive ions in the soil of Golmud area, the composite solutions of Na₂CO₃, NaCl, Na₂SO₄ and MgSO₄ were designed for full immersion test, the influence of glass powder/silica fume mixture on the durability of concrete was studied by the variation of relative quality evaluation parameter (ω₁) and relative dynamic modulus of Elasticity (ω₂) .The influence of glass powder/silica fume mixture on the hydration reaction of cementitious materials under standard curing condition was analysed and the microcosmic mechanism of glass powder/silica fume mixture concrete corroded incompound salt solution was discussed. The service life of concrete corroded by compound salt solution was predicted according to Wiener theory.The results showed that the degradation range of concrete in the corrosion environment of compound salt solution is different with the change of glass powder content. The hydration products of cementitious materials are not affected by the addition of glass powder/silica powder under standard curing condition, and the pozzolanic effect of SiO₂ is still obvious after curing from56 d to 120 d.When the content of glass powder is 10% and silica fume is 6%,the air hole structure of the concrete is improved, so the average air hole diameter of the concrete is smaller than that of the concrete without glass powder and silica fume. The glass powder should not exceed 10% when glass powder/silica powder is added to concrete.