不同因素对水泥混凝土抗离析特性的影响

Influence of different factors on the anti-separation properties of concrete

为探究水泥浆体黏度、粗集料体积和振捣频率对混凝土抗离析特性的影响,首先对不同水泥用量和水胶比下净浆和砂浆的塑性黏度进行了研究;其次研究了不同体积的粗集料在不同振捣频率(0、20、50Hz)下,在不同塑性黏度的净浆和砂浆中的平均下沉速率;最后通过灰色关联分析确定了水胶比、水泥用量和振捣频率和对粗集料平均下沉速率的影响程度。结果表明,水泥用量变化对新拌水泥净浆和砂浆的塑性黏度影响较小,水胶比变化对水泥净浆和砂浆的塑性黏度影响显著,随着水胶比的增加,水泥砂浆的塑性黏度逐渐减小;同一塑性黏度下,集料体积越大和振捣频率,平均下沉速率越大;通过灰色关联计算表明影响粗集料的平均下沉速率因素排序从大到小依次为振动频率、水胶比、水泥用量。

In order to in vestigate the effects of cement paste viscosity,coarse aggregate volume and pounding frequency on the anti-dissociation characteristics of concrete,firstly,the plastic viscosity of net paste and mortar with different cement dosage and water-cement ratio were investigated.Next,the average sinking rates of different volumes of coarse aggregates in net and mortar of different plastic viscosities at different vibrating frequencies(0,20,50 Hz)were investigated.Finally,the degree of influence of water-cement ratio,cement dosage and pounding frequency and on the average sinking rate of coarse aggregates were determined by grey correlation analysis.The results show that the change of cement dosage has a small effect on the plastic viscosity of fresh cement net mortar and mortar,and the change of water-cement ratio has a significant effect on the plastic viscosity of cement net mortar and mortar,and the plastic viscosity of cement mortar gradually decreases with the increase of water-cement ratio.The larger the volume of aggregate and the frequency of vibration under the same plastic viscosity,the larger the average sinking rate.The gray correlation calculation shows that the factors affecting the average sinking rate of coarse aggregate.The factors influencing the average sinking rate of coarse aggregate are,in descending order,vibration frequency,water-cement ratio,and cement dosage.