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为了评价高粉煤灰用量混凝土的强度,尤其是收缩特性,进行了室内研究。制备了用粉煤灰替代50%和70%普通硅酸盐水泥(OPC)的混凝土拌和物。水-胶凝材料比为0.28～0.34。有些混凝土拌和物还含有超塑化剂。报告了在20℃温度和65%相对湿度条件下养护的混凝土拌和物的强度和收缩特性。室内试验结果表明,高粉煤灰用量(HVFA)混凝土1d龄期获得令人满意的抗压和抗拉强度。试验结果还表明,取代50%OPC的HVFA混凝土,28d龄期及其后的强度高于OPC混凝土。低水-胶凝材料比的HVFA混凝土,其收缩值比OPC混凝土的降低30%。含超塑化剂的混凝土的收缩值比不含超塑化剂的混凝土的高50%。
In order to evaluate the strength, especially shrinkage, of concrete with high fly ash, indoor studies were conducted. Concrete mixes were prepared with fly ash instead of 50% and 70% ordinary portland cement (OPC). The water-binder ratio is 0.28-0.34. Some concrete mixes also contain superplasticizers. The strength and shrinkage characteristics of concrete mixes cured at 20 ° C and 65% relative humidity are reported. The laboratory test results show that the compressive strength and tensile strength of HVFA concrete at 1 day age are satisfactory. The test results also show that HVFA concrete, which replaced 50% OPC, had a higher strength at 28 days and thereafter than OPC concrete. HVFA concrete with lower water-cement ratio has a 30% reduction in shrinkage than OPC concrete. Concrete containing superplasticizer has a shrinkage value which is 50% higher than that of the concrete without superplasticizer.