-3℃养护下引气混凝土孔结构与抗渗性研究

Research of air-entraining concrete for pore structure characteristics and permeability under -3℃ curing condition

采用Auto Pore IV 9500全自动压汞仪和智能型多功能混凝土耐久性综合试验仪,分别研究负温(-3℃)及标准养护条件下,引气混凝土净浆孔结构特性和混凝土电通量随龄期增长的变化规律。研究结果表明:龄期越长,混凝土总孔体积、平均孔径、临界孔径、最可几孔径、孔隙率和电通量减小,而骨架密度增大。掺加0.01%引气剂,可以使混凝土平均孔径、临界孔径、最可几孔径、骨架密度和电通量减小,总孔体积和孔隙率增大。负温养护条件下,含气量为4.1%的混凝土渗透性与标准养护条件下相比,在28,56,84,112和140 d龄期内渗透性增长率在70.77%~114.35%之间波动。研究结果具有一定的实用价值和参考意义。

This experiment mainly adopts AutoPoreIV 9500 automatic mercury injection apparatus and intelligent multi-function concrete durability tester to respectively study pore structure characteristics of air-entraining concrete net pulp and concrete dentsu growth with the age under the -3 ℃ and standard curing condition. The results show that total intrusion volume, average pore diameter, the critical aperture, most probable aperture, porosity and electric flux decreases with the growth of age. But the skeleton density increases. Adding 0.01% air-entraining agent can make the concrete average pore diameter, the critical aperture, most probable aperture, skeleton density and electric flux decreases. At the same time, total intrusion volume and porosity increased. When the permeability with air content of concrete with 4.1% under ？3 ℃ curing condition compares with the standard curing condition within the 28, 56, 84, 112 and 140 d age, the permeability rate fluctuates between 70.77%~114.35%. This article has great practical value and reference significance through studying of air-entraining concrete for pore structure characteristics and permeability under -3 ℃ curing condition.