成秀珍，张德思

通过试验研究，探讨了强度等级、引气量水平、水灰比等因素对普通混凝土和粉煤灰混凝土抗冻融耐久性的影响．研究指出，混凝土的引气量和强度是影响普通混凝土和粉煤灰混凝土抗冻性的决定因素．满足抗冻性要求的引气量取决于相应的混凝土强度等级．美国标准ACI 318―83中对抗冻混凝土最小引气量、最大水灰比的限制，以及鲍尔氏(Powers)推荐的气泡间距指数(0.25 mm)都过于保守．给出了相应参数的推荐数值．
［关键词］　混凝土；抗冻性；粉煤灰；引气量；强度；气泡间距指数
［中图分类号］　TU528.2　［文献标识码］　A　［文章编号］　1001-7569(1999)04-0006-05

Research on the freeze/thaw durability of PFA concrete

CHENG Xiu-zhen, ZHANG De-si
(Department of Civil Engineering and Architecture,Northwest Polytechnical University, Xi’an 710072,China)

　　Abstract:Experimental studies on the freeze/thaw durability of OPC and PFA concrete are described.The effects of strength, air content levels,water/cement ratio, and PFA quality on the freeze/thaw durability of concrete were investigated.
　　The results indicated that air content and strength of the concrete had significant effects on the freeze/thaw durability of concrete with and without PFA.Required air content limits for frost resistant concrete depend on the grade of the concrete specified.The minimum air content and maximum water/cement ratio required by ACI 318-83 for freeze/thaw resistant concrete and Power’s recommended upper limit of 0.25 mm for the spacing factor may be too restrictive.New recommeded limits for the spacing are given.
　　PFA quality does not have a significant effect on the freeze/thaw durability of concrete, if the required air content and specified strength are achieved.
　　Key Words:concrete;freeze/thaw durability;PFA;air entrainment ;strength;spacing facotr