Evaluation of time-dependent rheological properties of cemented paste backfill incorporating superplasticizer with special focus on thixotropy and static yield stress  

掺减水剂尾砂膏体充填料浆流变参数的时效性研究

作　　者：WANG Xiao-lin WANG Hong-jiang WU Ai-xiang JIANG Hai-qiang PENG Qing-song ZHANG Xi 王小林;王洪江;吴爱祥;姜海强;彭青松;张玺(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China;Key Laboratory of High-Efficient Mining and Safety of Metal of Ministry of Education,University of Science and Technology Beijing,Beijing 100083,China;Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,Shenyang 110000,China)

机构地区：[1]School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China [2]Key Laboratory of High-Efficient Mining and Safety of Metal of Ministry of Education,University of Science and Technology Beijing,Beijing 100083,China [3]Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,Shenyang 110000,China

出　　处：《Journal of Central South University》2022年第4期1239-1249,共11页中南大学学报（英文版）

基　　金：Project(51834001)supported by the National Natural Science Fundation of China;Project(N2101043)supported by the Fundamental Research Funds for the Central Universities of China。

摘　　要：Superplasticizers are widely used to reduce the pipe flow resistance of cemented paste backfill(CPB), which is characterised by high concentration and high yield stress. This study aimed to assess the time-dependent rheological properties of CPB containing superplasticizer, with special focus on static yield stress and thixotropy. The results indicate that with the increase of the superplasticizer dosage, the static yield stress, dynamic yield stress and thixotropy of CPB decreased significantly, while the plastic viscosity decreased slightly. The curing time has a significant effect on the static yield stress, dynamic yield stress and thixotropy of CPB containing superplasticizer, which increase by 46.6%-87.1%,15.2%-35.6% and 79.4%-138.2%, respectively, within 2 h. The static yield stress, dynamic yield stress and thixotropy of CPB without superplasticizer only increase by 4.9%, 6.3% and 16.1%, respectively, within 2 h. The curing time has a significant influence on the plastic viscosity of CPB regardless of superplasticizer addition, the plastic viscosity increases by 13.2%-19.7% within 2 h. Regardless of superplasticizer dosage, plotting of both static yield stress and dynamic yield stress versus thixotropy produces clearly linear curves. The findings of this study are conducive to the design of pipe transportation of CPB containing superplasticizer.采用流变测试方法研究掺减水剂的胶结膏体随时间变化的流变参数,特别关注静态屈服应力和触变性。结果表明,随减水剂用量的增加,胶结膏体的静态屈服应力、动态屈服应力和触变性显著降低,塑性黏度几乎不变。养护时间对掺减水剂胶结膏体的静态屈服应力、动态屈服应力和触变性有显著影响,在2 h内分别提高了46.6%~87.1%、15.2%~35.6%和79.4%~138.2%。无减水剂胶结膏体的静态屈服应力、动态屈服应力和触变性在2 h内仅分别提高4.9%、6.3%和16.1%。无论是否添加减水剂,养护时间对胶结膏体的塑性黏度有较大影响,2 h内塑性黏度增大13.2%~19.7%。无论是否添加减水剂,胶结膏体的触变性随静态屈服应力、动态屈服应力呈线性函数增长。研究结果对掺减水剂胶结膏体的管道输送设计有一定的指导意义。

关 键 词：cemented paste backfill SUPERPLASTICIZER curing time yield stress THIXOTROPY 

分 类 号：TD803[矿业工程—矿山开采]