摘要
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 ACI31 8- 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 .2 5mm)都过于保守。
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 freeze/thaw durability of fifty different concrete mixes including normal 15, 20, 30, 40 and 50 MPa strength OPC and PFA concrete were tested at the 1.0%, 2.5%, 3.5%, 4.5% and 5.5% air content levels. The test results indicated that air content and strength of the concrete have 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 0.25mm for the spacing factor may be too restrictive. New recommended limits for the air content and spacing factor are given in Table 1 and 2.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2000年第2期175-178,共4页
Journal of Northwestern Polytechnical University
关键词
混凝土
抗冻性
粉煤灰
引气量
耐久性
concrete, air content, freeze/thaw durability, PFA, spacing factor, strength
