【摘要】 本文是针对国产回转窑烧结法矾土水泥配制的混凝土,在通过大量的实验室快速试验和不同自然条件地区长期龄试验结果的基础上写成的。与前人已发表的采用电炉熔融所制得的高铁矾土水泥混凝土所得的结论相近似。文章论述了强度下降的原因是由于低钙铝酸盐水化物转化成高钙铝酸盐水化物和铝胶结晶,造成晶体间结合力降低,孔隙率增加。强度下降的速度与环境温湿度等条件有关,高温高湿时强度下降速度加快。指出矾土水泥混凝土强度下降不是无止境的,存在着最低强度值。提出决定该值大小的主要因素是水灰比,也与水泥矿物组成等有关。并建议用50℃水热养护法确定该值。还提出了国产回转窑烧结法矾土水泥混凝土最低强度值估算的数学表达公式。更多还原

【Abstract】 Aluminous cement of low iron content made from the clinker burnt to incipient fusionin rotary kiln was used to prepare concrete specimens. Long term examinations under va-rious natural conditions and rapid laboratory tests on strength were performed. Similar re-sults were obtained as those published in the previous literature using aluminous cement ofhigh iron content made by fusion process in electric furnace. The reduction of strength ofthe concrete was found due to the conversion of hydrate of low calcium aluminate into thehigh calcium form and the crystallization of alumina gel ensuing in the weakening of thebinding force between the hydrated crystals and the increasing of porosity of the cementpaste. The rate of strength reduction was related to the environment conditions, i.e. tem-perature and humidity. The strength of concrete decreased rapidly with both high temperature and high humidity. But the reduction of the strength was not infinite. There existsa minimum value of strength.The main factor affecting their value is the water to cementratio of concrete.The mineral composition of the cement plays a minor role. The minimumvalue can be determined by hydrothermal curing the test specimens at 50℃. A mathmaticalexpression for estimating the minimun strength of aluminous cement concrete made fromclinker burned in rotary kiln has also been given.更多还原