成秀珍，張德思

通過試驗研究，探討了強度等級、引氣量水平、水灰比等因素對普通混凝土和粉煤灰混凝土抗凍融耐久性的影響．研究指出，混凝土的引氣量和強度是影響普通混凝土和粉煤灰混凝土抗凍性的決定因素．滿足抗凍性要求的引氣量取決于相應的混凝土強度等級．美國標準ACI 318―83中對抗凍混凝土最小引氣量、最大水灰比的限制，以及鮑爾氏(Powers)推薦的氣泡間距指數(0.25 mm)都過于保守．給出了相應參數的推薦數值．
［關鍵詞］　混凝土；抗凍性；粉煤灰；引氣量；強度；氣泡間距指數
［中圖分類號］　TU528.2　［文獻標識碼］　A　［文章編號］　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