浇筑密实度和均匀度对结构混凝土耐久性的影响

Effect of Casting Consolidation and Uniformity on Durability of Structural Concrete

为建立浇筑期结构混凝土耐久性质量控制方法,采用振动分层法,研究了混凝土浇筑密实度、浇筑均匀度对其渗透性的影响,建立了混凝土浇筑密实度和浇筑均匀度的量化控制方法——电阻率稳定区间法.结果表明:混凝土浇筑密实度和浇筑均匀度均决定于材料流动性和振捣时间;相比混凝土抗压强度,混凝土渗透性对浇筑密实度和浇筑均匀度更为敏感.通过计算量化判定电阻率稳定区间(SRER),并以其起点为判别点,可以保证混凝土浇筑密实度和浇筑均匀度处于综合最优状态,优化混凝土孔隙结构,显著提升混凝土抗渗透性能.

To establish quality control method to guarantee the durability of structural concrete during casting construction,effects of casting consolidation and uniformity on the permeability of concrete were researched by using separation-vibrated method.Then a quantified method,defined as the stable region of electrical resistivity method,was proposed to evaluate casting consolidation and uniformity of concrete.The experimental results indicate that casting consolidation and uniformity are determined not only by fluidity property of fresh concrete,but also by vibrating time.The permeability of concrete is much more sensitive to casting consolidation and uniformity than the compressive strength.The optimum of casting consolidation and uniformity can be achieved via judging the start of stable region of electrical resistivity,so as to optimize the pore structures of concrete,and improve the resistance against the permeability of concrete significantly.