By the addition of superplasticizer and air entraining agent,manufactured sand selfcompacting concrete(MS SCC)with slump flow varying from 500 to 700 mm and air content varying from 2.0%to 9.0%were prepared and the pu...By the addition of superplasticizer and air entraining agent,manufactured sand selfcompacting concrete(MS SCC)with slump flow varying from 500 to 700 mm and air content varying from 2.0%to 9.0%were prepared and the pumpability of MS SCC was studied by a sliding pipe rheometer(Sliper).According to the Kaplan’s model,the initial pump pressure and the pump resistance of MS SCC were obtained.Meanwhile,rheological properties including the yield stress and the plastic viscosity of MS SCC were measured by a rheometer.The experimental results show that the increase of slump flow contributes to a higher pumpability and a proper air content,i e,6%is beneficial for the pumpability of MS SCC.Due to the existence of stone powder and stronger angularity of MS,the initial pump pressure of MS SCC is only about 60%-88%that of river sand(RS)SCC with the same slump flow and air content,indicating that MS SCC possesses a higher pumpability than RS SCC.展开更多
The mortar pumpability is essential in the construction industry,which requires much labor to estimate manually and always causes material waste.This paper proposes an effective method by combining a 3-dimensional con...The mortar pumpability is essential in the construction industry,which requires much labor to estimate manually and always causes material waste.This paper proposes an effective method by combining a 3-dimensional convolutional neural network(3D CNN)with a 2-dimensional convolutional long short-term memory network(ConvLSTM2D)to automatically classify the mortar pumpability.Experiment results show that the proposed model has an accuracy rate of 100%with a fast convergence speed,based on the dataset organized by collecting the corresponding mortar image sequences.This work demonstrates the feasibility of using computer vision and deep learning for mortar pumpability classification.展开更多
Tailings consolidation and discharging technology is currently a popular means for disposing tailings in China. In this study, we describe a laboratory investigation of the unclassified tailings slurry from an iron mi...Tailings consolidation and discharging technology is currently a popular means for disposing tailings in China. In this study, we describe a laboratory investigation of the unclassified tailings slurry from an iron mine and analyze the influence of the concentration,amount of consolidation agent, and types of consolidation agent on the pumpability in terms of the slump, slump flow, and bleeding rate of the slurry. The results indicate that an increase in concentration leads to a pronounced decrease in the magnitude of the slump, slump flow,and the bleeding rate. Compared with the consolidation agents P.O42.5 and P.S.A32.5, the new consolidation agent offers substantial advantages in promoting the pumping performance of the slurry. The concentration more strongly affects the slump, slump flow, and the bleeding rate of the slurry than does the amount of the consolidation agent. We also constructed the pumpability interval of the slurry on the basis of the slump and bleeding rate and accordingly determined the proportioning parameters of the slurry with a concentration of 75 wt% to79 wt% and with a consolidation agent concentration of 2 wt%. In addition, we discussed the pumpability mechanism of the slurry.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.U1934206 and 52108260)the Foundation of China Academy of Railway Science Corporation Limited(No.2020YJ049)。
文摘By the addition of superplasticizer and air entraining agent,manufactured sand selfcompacting concrete(MS SCC)with slump flow varying from 500 to 700 mm and air content varying from 2.0%to 9.0%were prepared and the pumpability of MS SCC was studied by a sliding pipe rheometer(Sliper).According to the Kaplan’s model,the initial pump pressure and the pump resistance of MS SCC were obtained.Meanwhile,rheological properties including the yield stress and the plastic viscosity of MS SCC were measured by a rheometer.The experimental results show that the increase of slump flow contributes to a higher pumpability and a proper air content,i e,6%is beneficial for the pumpability of MS SCC.Due to the existence of stone powder and stronger angularity of MS,the initial pump pressure of MS SCC is only about 60%-88%that of river sand(RS)SCC with the same slump flow and air content,indicating that MS SCC possesses a higher pumpability than RS SCC.
基金supported by the Key Project of National Natural Science Foundation of China-Civil Aviation Joint Fund under Grant No.U2033212。
文摘The mortar pumpability is essential in the construction industry,which requires much labor to estimate manually and always causes material waste.This paper proposes an effective method by combining a 3-dimensional convolutional neural network(3D CNN)with a 2-dimensional convolutional long short-term memory network(ConvLSTM2D)to automatically classify the mortar pumpability.Experiment results show that the proposed model has an accuracy rate of 100%with a fast convergence speed,based on the dataset organized by collecting the corresponding mortar image sequences.This work demonstrates the feasibility of using computer vision and deep learning for mortar pumpability classification.
基金financially supported by the Fundamental Research Funds for the Central Universities of China (No. FRF-TP-16-073A1)the State Key Research Development Program of China (Nos. 2017YFC0804103 and 2016YFC0600801)the National Key Basic Research Program of China (973 Program) (No. 2015CB060200)
文摘Tailings consolidation and discharging technology is currently a popular means for disposing tailings in China. In this study, we describe a laboratory investigation of the unclassified tailings slurry from an iron mine and analyze the influence of the concentration,amount of consolidation agent, and types of consolidation agent on the pumpability in terms of the slump, slump flow, and bleeding rate of the slurry. The results indicate that an increase in concentration leads to a pronounced decrease in the magnitude of the slump, slump flow,and the bleeding rate. Compared with the consolidation agents P.O42.5 and P.S.A32.5, the new consolidation agent offers substantial advantages in promoting the pumping performance of the slurry. The concentration more strongly affects the slump, slump flow, and the bleeding rate of the slurry than does the amount of the consolidation agent. We also constructed the pumpability interval of the slurry on the basis of the slump and bleeding rate and accordingly determined the proportioning parameters of the slurry with a concentration of 75 wt% to79 wt% and with a consolidation agent concentration of 2 wt%. In addition, we discussed the pumpability mechanism of the slurry.
