矿物掺合料对轨枕混凝土耐久性能影响的研究

Research on the durability of sleeper concrete containing mineral admixtures

研究磷矿渣、粉煤灰及磨细矿渣粉不同掺量对轨枕混凝土氯离子电通量及抗冻性能的影响,并分析了矿物掺合料对轨枕混凝土耐久性能的作用机理,结果表明:矿物掺合料的掺入改善了轨枕混凝土抗氯离子渗透性能;3种矿物掺合料相比较,掺矿渣轨枕混凝土抗氯离子渗透性能最佳;经过300次冻融循环,掺矿物掺合料的轨枕混凝土各抗冻指标保持完好。矿物掺合料掺量为30%时,掺矿渣、粉煤灰及磷矿渣的轨枕混凝土300次冻融循环的相对动弹性模量达到基准混凝土的113%、116%和119%;50～300次冻融循环的质量损失率均低于基准混凝土的60%。

The effect and the mechanism of phosphorus slag,granulated blast furnace slag and fly ash with different replacement dosage on the durability of sleeper concrete（resistance of freezing-thaw and resistance of chloride permeability） were demonstrated.The results presented that the resistance of chloride permeability of sleeper concrete becomes increasingly better by replacing cement with mineral admixtures.Comparatively speaking,the best effect to enhance the resistance of chloride permeability of sleeper concrete is gained by adding granulated blast furnace slag.After 300 freezing-thaw cycle tests,the resistance of freezing-thaw of sleeper concrete containing mineral admixtures is quite well.When the replacement dosage is 30%,the relative dynamic elastic modulus of sleeper concrete containing granulated blast furnace slag,fly ash and phosphorus slag arrives at 113%,116% and 119% of that of reference sleeper concrete.During 50~300 freezing-thaw cycle tests,the relative mass loss rate of sleeper concrete adding mineral admixture are almost below 60% of that of reference sleeper concrete.