矿物掺合料对高性能混凝土耐久性的影响

The Effect of Mineral Admixtures on the Durability Performance of High Performance Concrete

研究了粉煤灰、矿渣粉的不同掺入方式对高性能混凝土(HPC)抗氯离子渗透性能及抗冻性能的影响。结果表明:在相同水胶比条件下,随着矿物掺合料掺量的增加,HPC的抗压强度逐渐降低;掺入适量的矿物掺合料可有效降低HPC的电通量,改善抗氯离子渗透性能;当矿物掺合料掺量为40%,且粉煤灰和矿渣粉质量复掺比例为3∶1时,HPC在28 d与84 d的电通量分别为641.6 C和380.5 C;在水胶比及含气量不变的情况下,随着矿物掺合料掺量的增加,HPC的抗冻性能逐渐变差,而未掺矿物掺合料的HPC抗冻性能最好,抗冻等级为F200。

The effect of different mixing methods of fly ash and slag powder on the anti-chloride ion permeability and frost resistance of high performance concrete(HPC)were studied.The results show that the compressive strength of HPC decreases with the increase of mineral admixture when the water-binder ratio and air content are unchanged.The appropriate amount of mineral admixture can effectively reduce the electrical flux of HPC.And the resistance of HPC to chloride ion penetration is improved.When the content of mineral admixture is 40%and m(fly ash)∶m(slag powder)is 3∶1,the electric flux of concrete at the 28 d and 84 d is 641.6 C and 380.5 C respectively.With the addition of mineral admixtures,the frost resistance of concrete gradually deteriorates.The antifreeze performance of HPC without mineral admixture is the best,and the antifreeze grade is F200.