大掺量高钙粉煤灰水泥浆体体积安定性控制研究

试验采用喷雾结合人工翻拌、库内堆放水化消解5～7d、水泥磨机粉磨使细度达到Ⅱ级灰标准等技术措施,虽然高钙灰掺量高达60%时,其水泥浆体雷氏膨胀量仍满足规范要求,有效地解决了高钙灰在水工碾压混凝土中应用的技术难题.目前,高钙灰已进行了规模性生产和施工应用,技术经济效益明显.试验还发现,高钙灰中游离氧化钙含量大于规范要求(≤4%)时,其蒸煮安定性仍然合格.规范采用游离氧化钙含量和蒸煮安定性合格两项指标判断高钙灰合格与否值得商榷,实际工程使用应以蒸煮安定性合格来控制.

Study on volume stability control of cement paste with large amount of high-calcium fly ash

The Le Chatelier's expansion value of the cement paste with more than 60 percents HCFA still conformed to the code by adopting the spray fog,chemical reaction with water about 5 to 7 days and whetting techniques.Therefore those measures effectively solve the technique difficulties of the HCFA's application in the hydraulic roller compacted concrete.At present,the HCFA has been large scale produced and applied in construction for its predominant economic benefits.And tests indicate the HCFA cooking stability still conform to the code though the percent of free calcium oxide is over the code which is lower than 4 percent.Whether it is appropriate is to be studied to judge the HCFA's conforming to the code according to the indexes of the percent of free calcium oxide and the cooking stability.It is proposed to control the HCFA application according to the its cooking stability conforming to the code.