Zhang Zhao, Feng Qingge, Zhu Weiwei, Lin Xianhao, Chen Kao, Yin Wuxiao, Lu Changhai
School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
Materials and Environmental Engineering, Guangxi University for Nationalities, Nanning 530004, China.
Materials (Basel). 2021 Aug 26;14(17):4850. doi: 10.3390/ma14174850.
Previous studies demonstrated that water film thickness (WFT) is a key factor that affects the fluidity of mortar. Changes in the sand-cement (S/C) ratio and polycarboxylate superplasticizer (PCE) dosage will affect the WFT. In this study, several mortar samples with different S/C ratios and different PCE dosages were prepared, and the basic properties of the mortar were measured. The results show that as the S/C ratio increases, the packing density of the mortar will decrease, the WFT will decrease, and the cohesiveness will increase, resulting in a decrease in the flow spread and strength of the mortar. When the PCE dosage is increased, the packing density of the mortar will increase, the WFT will increase, and the cohesiveness will decrease, which increases the flow spread of the mortar. When the water-cement (W/C) ratio is low, the S/C ratio has a significant effect on the strength, and the strength will increase with the increasing of the PCE dosage. When the W/C ratio is high, the strength of the mortar will be reduced once the PCE dosage exceeds the saturation value. In the case of different S/C ratios or different PCE dosages, the WFT can be used as a measure of mortar cohesiveness and flow spread.
先前的研究表明，水膜厚度（WFT）是影响砂浆流动性的关键因素。砂灰比（S/C）和聚羧酸系高效减水剂（PCE）用量的变化会影响水膜厚度。在本研究中，制备了几种具有不同砂灰比和不同PCE用量的砂浆样品，并测定了砂浆的基本性能。结果表明，随着砂灰比的增加，砂浆的堆积密度会降低，水膜厚度会减小，内聚性会增加，导致砂浆的流动扩展度和强度降低。当PCE用量增加时，砂浆的堆积密度会增加，水膜厚度会增大，内聚性会降低，这会增大砂浆的流动扩展度。当水灰比（W/C）较低时，砂灰比对强度有显著影响，且强度会随着PCE用量的增加而提高。当水灰比高时，一旦PCE用量超过饱和值，砂浆的强度就会降低。在不同砂灰比或不同PCE用量的情况下，水膜厚度可作为衡量砂浆内聚性和流动扩展度的指标。
