Effects of packing density and water film thickness on the fluidity behaviour of cemented paste backfill

2020 ◽  
Vol 359 ◽  
pp. 27-35 ◽  
Author(s):  
Jingping Qiu ◽  
Zhenbang Guo ◽  
Lei Yang ◽  
Haiqiang Jiang ◽  
Yingliang Zhao
2020 ◽  
Vol 32 (10) ◽  
pp. 444-455 ◽  
Author(s):  
Guillermina Marchetti ◽  
Edgardo Fabián Irassar ◽  
Viviana Fátima Rahhal

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4850
Author(s):  
Zhao Zhang ◽  
Qingge Feng ◽  
Weiwei Zhu ◽  
Xianhao Lin ◽  
Kao Chen ◽  
...  

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.


2013 ◽  
Vol 438-439 ◽  
pp. 67-71
Author(s):  
Qian Qian Zhang ◽  
Jian Zhong Liu ◽  
Jia Ping Liu

The effects of ground slag with different specific surface area on the rheology of mortar at water-binder ratio of 0.25, 0.28 and 0.30 were investigated, and the combined effects of packing density and solid surface area on the rheology of mortar were evaluated in terms of the water film thickness. The results show that with the increasing of specific surface area of slag (220 m2/kg-784 m2/kg), plastic viscosity and yield stress decrease. The correlations of yield stress and plastic viscosity to the water film thickness are basically linear with high correlation R2 values. The action of the ground slag on the rheology of mortar can be characterized by water film thickness, and with the increasing of water film thickness the rheological parameters decrease.


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