Effects of particle size distribution, shape and volume fraction of aggregates on the wall effect of concrete via random sequential packing of polydispersed ellipsoidal particles

Influence of formwork material on transport properties of self-consolidating concrete near formed surfaces

“…For greater distance from the simulated rigid plane, the volume fraction of spherical particles decreased to reach the mean value of the bulk medium [9]. Xu et al [13] also found similar results using ellipsoid particles as aggregates. Accordingly, in their mesostructure model the specific surface area of the solid phase in the boundary zone had a 17% of coarse aggregate volume higher than bulk material at a distance of approximately Deq /2 where Deq is the equivalent diameter of ellipsoid particles.…”

“…The study by Kreijger did not provide discussion regarding to the distribution of coarse aggregate in the first centimeter of formed concrete surfaces. Numerical with the packing density of spherical aggregates against formed surfaces indicate that the disturbed zone's thickness of a material due to the presence of a rigid plane surface corresponds to the maximum size of coarse aggregate (Dmax) [9][10][11][12][13]. Zheng et al [9] carried out numerical simulations of spherical particles of sizes ranging between 5 and 16 mm employed at mean volume fractions ranging between 35% and 50%.…”

Determination of the Corrosion Rate of Steel Bars in Concrete Based on the Porosity of Interfacial Zone

“…grain volume fraction α c in the interfacial zone. The "wall effect" has been extensively studied in previous researches, some studies are mainly focused on the numerical explanation of the "wall effect," among which, random packing models of particles have been developed and proved to be effective (Xu and Chen, 2012a;Xu and Chen, 2012b;Xu and Chen, 2013;Xu et al, 2013a;Xu et al, 2013b;Xu et al, 2019). These models can describe the mesostructure of concrete by randomly packing the 2D or 3D particles, considering that concrete is composed of randomly packed aggregate particles and cement particles.…”

An integrated framework for modelling virtual 3D irregulate particulate mesostructure

“…On the contrary, the second approach virtually generates several models and computationally cost lower. The method of virtual fabrication for mesostructure has been broadly utilized to characterize mesoscopic structural properties [10][11][12][13].…”