Discrete-element modeling of shear-induced particle migration during concrete pipe flow: Effect of size distribution and concentration of aggregate on formation of lubrication layer

Tavangar, Tooran; Hosseinpoor, Masoud; Marshall, Jeffrey S.; Yahia, Ammar; Khayat, Kamal H.

doi:10.1016/j.cemconres.2023.107113

Cited by 13 publications

(5 citation statements)

References 53 publications

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“…According to the coarse aggregate particle size of the same specifications to meet the concrete grade, a gravel pile of 5~25 mm coarse aggregates is randomly selected several times, and Figure 5 shows the actual particle size distribution of coarse aggregates obtained through sampling analysis. According to Equations ( 2), (3), and (10), the empirical formula giving the pressure loss per unit length is calculated as follows:…”

Section: Analysis Of Experimental Resultsmentioning

confidence: 99%

“…Related scholars have launched a series of research into the rheological characteristics of concrete aggregate particles in the pumping process [7], such as rheological behavior analysis [8], pumping model construction [9], and pressure loss impact analysis [10]. In the pumping process, the concrete in the pumping pipe moves forward in the pump pipe under the action of pressure.…”

Section: Introductionmentioning

confidence: 99%

“…The aggregates and mortar generate a nonuniform shear 2 of 14 field under the combined effect of the pumping pressure and friction on the pipe wall. The aggregate particles move from high shear force area to low shear force area, and the mortar is squeezed to the pipe wall through the aggregate gaps, causing the concrete in the pumping pipe to be divided into a lubrication layer and a plunger layer [10,11]. Some scholars used ultrasonic detection to measure the thickness of the lubrication layer at different flow rates, discovering that the flow behavior of the lubrication layer is similar to that of mortar [12].…”

Section: Introductionmentioning

confidence: 99%

“…Coarse aggregate particles' shape [21] and distribution characteristics [22] affect the rheological properties of concrete, which directly affect the pumping pressure loss [23]. Choi et al [24] used three different coarse aggregate sizes to run the 170 m and 1000 m pumping circuit tests to measure the pumping pressure at the same flow rates, and the results showed a linear relationship between the pumping pressure and flow rate.…”

Section: Introductionmentioning

confidence: 99%

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One-Dimensional Modeling of the Pressure Loss in Concrete Pumping and Experimental Verification

Zhao,

Gao,

Wan

et al. 2024

Applied Sciences

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An accurate formula for calculating the pressure loss in concrete pumping plays a significant guiding role in the design and service process of pump trucks. Based on the flow characteristics of concrete pumping, a straight pipe one-dimensional model for the pressure loss is developed, in which both the viscous force of the mortar in the lubrication layer and the blocking effect of coarse aggregate particles are considered. First, the complex geometrical shapes of the aggregate particles are geometrically reconstructed by using a HandySCAN noncontact scanner and the reverse modeling software Geomagic Design X (v.19.0.2). Then, the equivalent spherical size of nonspherical aggregate particles is calculated according to the equal hydraulic radius principle. The blocking effect of the aggregate particles is converted into the wall roughness. Finally, an explicit expression for the pressure loss in concrete pumping is deduced by using Modi’s equation, Bernoulli’s equation, and Darcy’s formula, and the calculated value is compared with the measured value at a corresponding experimental site. The results indicate that the pressure loss values calculated with the one-dimensional flow model are closer to the actual pumping pressure loss values. The relative error between the results and the actual pumping pressure loss value is about 20.2%.

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Section: Analysis Of Experimental Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

One-Dimensional Modeling of the Pressure Loss in Concrete Pumping and Experimental Verification

Zhao,

Gao,

Wan

et al. 2024

Applied Sciences

View full text Add to dashboard Cite

show abstract

“…Furthermore, they modified the rolling-resistance model based on JKR to obtain the relationship between the surface energy and Young's modulus. Cui et al [21], Su et al [22], and Tavangar et al [23] used the DEM method to establish a new self-compacting-concrete model and explore the relationship between the blockage phenomenon of self-compacting concrete and the distribution of coarse aggregate. They revealed the relationship between the rebound rate of shotcrete and the spraying distance, shrinkage angle, and initial velocity under different particle sizes.…”

Section: Introductionmentioning

confidence: 99%

Rebound Characteristics of Wet-Shotcrete Particle Flow Jet from Wall Based on CFD-DEM

Chen,

Zhang,

et al. 2024

Buildings

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This paper aims to reveal the motion law and collision behaviors of shotcrete particle flow jets. A physical model of the jet flow field composed of a nozzle structure and jet area was constructed and meshes with various sizes were used to mesh the nozzle and jet area. With the basic contact parameters and contact model parameters of the particles set, the CFD-DEM-coupling simulation method was adopted to perform the numerical simulation of concrete-particle-flow-jet impingement. The variation laws of the continuous-phase velocity and pressure drop of the shotcrete, coarse-aggregate motion characteristics, and particle collision behavior under the interaction of the continuous and discrete phases were obtained. The results showed that the velocity field and pressure-drop field of the continuous phase had an ideal symmetry in the XY plane in the stable injection stage, the continuous-phase velocity gradually increased inside the nozzle and gradually decreased after entering the jet area, the continuous-phase pressure drop was the maximum at the nozzle inlet, and the pressure value at the nozzle outlet became atmospheric pressure. The central axis of the particle flow jet was displaced by 0.15 m in the negative direction of the Y-axis under the action of gravity, the diffusion angle of the small particles that exited the nozzle and entered the jet area was larger than that of the large particles, and the large-particle jets were more concentrated and easier to spray into the designated spraying areas. The particle flow reached a stable jet state about 0.3 s after the jet began, and the peak velocity of the 4 mm particles in the flow reached 25 m/s, while the peak velocity of the 12 mm particles was only 19 m/s. The acceleration time for particles of different sizes to reach the peak velocity also varied, and the large particles took longer to reach the maximum velocity: small particles reached their peak within 0.4 m–8 m of the jet area, and large particles reached their peak within 0.8 m–1.2 m of the jet area. The particle velocity peaked within 0.6 m–1 m of the jet area. Particle collision took three forms: particle collision with the inner wall of the nozzle, interparticle collision, and particle collision with the sprayed wall. The collision between the particles and the sprayed wall was the main form leading to the rebound of the wet shotcrete, and the rebound angle after particle collision was uncertain.

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Mesoscopic discrete modeling of compression and fracture behavior of concrete: Effects of aggregate size distribution and interface transition zone

Yang,

Li,

et al. 2024

Cement and Concrete Composites

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Discrete-element modeling of shear-induced particle migration during concrete pipe flow: Effect of size distribution and concentration of aggregate on formation of lubrication layer

Cited by 13 publications

References 53 publications

One-Dimensional Modeling of the Pressure Loss in Concrete Pumping and Experimental Verification

One-Dimensional Modeling of the Pressure Loss in Concrete Pumping and Experimental Verification

Rebound Characteristics of Wet-Shotcrete Particle Flow Jet from Wall Based on CFD-DEM

Mesoscopic discrete modeling of compression and fracture behavior of concrete: Effects of aggregate size distribution and interface transition zone

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