{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,6]],"date-time":"2026-04-06T12:01:51Z","timestamp":1775476911499,"version":"3.50.1"},"reference-count":33,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2025,11,12]],"date-time":"2025-11-12T00:00:00Z","timestamp":1762905600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>To reveal the mesoscopic fracture mechanism of fissured concrete, this study employed the discrete element method (DEM) and adopted the parallel bond model (PBM) within the two-dimensional particle flow code (PFC2D) to construct a mesoscopic model of concrete semi-circular bending (SCB) specimens with prefabricated fissures. Three sets of schemes were designed by varying prefabricated fissure angles (0\u201345\u00b0), aggregate contents (30\u201345%), and porosities (3\u20136%), and numerical simulations of three-point bending loads were conducted to explore the effects of each parameter on the crack propagation law and load-bearing performance of the specimens. Validation was performed by comparing the simulated load\u2013displacement curves with the typical quasi-brittle mechanical characteristics of concrete (exhibiting \u201clinear elastic rise\u2013pre-peak stress fluctuation\u2013nonlinear decline\u201d) and verifying that the DEM could accurately capture the entire process from microcrack initiation at the aggregate\u2013mortar interface, crack deflection\/bifurcation induced by pores, to macroscopic fracture penetration\u2014consistent with the known mesoscopic damage evolution law of concrete. The results indicate that the crack propagation mode evolves from straight extension to tortuous branching as parameters change. Moreover, the peak strength first increases and then decreases with the increase in each parameter: when the fissure angle is 15\u00b0, the aggregate content is 35%, and the porosity is 4%, the specimens achieve an optimal balance between crack propagation resistance and energy dissipation, resulting in the best load-bearing performance. Specifically, the prefabricated fissure angle dominates the stress type (tension\u2013shear transition); aggregates regulate crack resistance through a \u201cblocking\u2013diverting\u201d effect; and pores, acting as defects, influence stress concentration. This study verifies the reliability of DEM in simulating concrete fracture behavior, enriches the mesoscopic fracture theory of concrete, and provides reliable references for the optimization of concrete material proportioning (e.g., aggregate\u2013porosity ratio adjustment) and anti-cracking design of infrastructure (e.g., pavement, tunnel linings) in engineering practices.<\/jats:p>","DOI":"10.3390\/ma18225140","type":"journal-article","created":{"date-parts":[[2025,11,12]],"date-time":"2025-11-12T10:56:47Z","timestamp":1762945007000},"page":"5140","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Investigating the Cracking Processes and Bearing Performance of Fissured Concrete SCB Specimens via DEM-Based Mesoscopic Modeling Considering Fissure Angle, Aggregate Content and Porosity"],"prefix":"10.3390","volume":"18","author":[{"given":"Qinrong","family":"Li","sequence":"first","affiliation":[{"name":"Transport Planning and Research Institute, Ministry of Transport, Beijing 100028, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Suyi","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Architectural and Hydraulic Engineering, Jiujiang Polytechnic University of Science and Technology, Jiujiang 332020, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yifei","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Huzhou University, Huzhou 313002, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mingyue","family":"Qiu","sequence":"additional","affiliation":[{"name":"School of Transportation and Civi Engineering, Nantong University, Nantong 226019, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ruitong","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Transportation and Civi Engineering, Nantong University, Nantong 226019, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cheng","family":"Chen","sequence":"additional","affiliation":[{"name":"College of Mechanics and Engineering Science, Hohai University, Nanjing 210098, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5479-1192","authenticated-orcid":false,"given":"Shuyang","family":"Yu","sequence":"additional","affiliation":[{"name":"School of Transportation and Civi Engineering, Nantong University, Nantong 226019, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"104416","DOI":"10.1016\/j.tust.2022.104416","article-title":"Propagation characteristics and prediction of blast-induced vibration on closely spaced rock tunnels","volume":"123","author":"Wang","year":"2022","journal-title":"Tunn. Undergr. Space Technol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"105136","DOI":"10.1016\/j.tafmec.2025.105136","article-title":"Analysis and prediction of dynamic stress concentration in jointed coal using boundary element method","volume":"140","author":"Wang","year":"2025","journal-title":"Theor. Appl. Fract. Mech."},{"key":"ref_3","first-page":"183","article-title":"Analytical theory on instability sliding of surrounding rock blocks in tunnel roof under stress wave actions","volume":"56","author":"Xiao","year":"2024","journal-title":"Chin. J. Theor. Appl. Mech."},{"key":"ref_4","first-page":"4495","article-title":"Analytical theoretical study on ultra-low friction characteristics of coal rock interfaces under stress wave action","volume":"49","author":"Wang","year":"2024","journal-title":"J. China Coal Soc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"121088","DOI":"10.1016\/j.oceaneng.2025.121088","article-title":"Shape parameterization method and hydrodynamic noise characteristics of low-noise toroidal propeller","volume":"328","author":"Liu","year":"2025","journal-title":"Ocean Eng."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1007\/s12583-022-1729-7","article-title":"Petrogenesis and tectonic implications of the tertiary choke shield basalt and continental flood basalt from the central Ethiopian plateau","volume":"34","author":"Khan","year":"2023","journal-title":"J. Earth Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1007\/s12583-021-1435-x","article-title":"Origin and evolution of ultramafic rocks along the Sagaing fault, Myanmar","volume":"34","author":"Morishita","year":"2023","journal-title":"J. Earth Sci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"144213","DOI":"10.1016\/j.conbuildmat.2025.144213","article-title":"Investigating the crack propagation processes of grouted\/ungrouted fissured tunnel specimens using 3D printing technology and SPH simulation method","volume":"500","author":"Yu","year":"2025","journal-title":"Constr. Build. Mater."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"114062","DOI":"10.1016\/j.jobe.2025.114062","article-title":"Effect of notch-to-depth ratio on shear fracture properties of plain and fiber-reinforced manufactured sand concrete using double notched cube test","volume":"113","author":"Cai","year":"2025","journal-title":"J. Build. Eng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"104646","DOI":"10.1016\/j.tafmec.2024.104646","article-title":"Experimental and numerical investigations on rate-dependent fracture behavior of concrete-rock interface","volume":"133","author":"Yao","year":"2024","journal-title":"Theor. Appl. Fract. Mech."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"124581","DOI":"10.1016\/j.conbuildmat.2021.124581","article-title":"Numerical fracture investigation of single-edge notched asphalt concrete beam based on random heterogeneous FEM model","volume":"304","author":"Teng","year":"2021","journal-title":"Constr. Build. Mater."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"104463","DOI":"10.1016\/j.mechrescom.2025.104463","article-title":"Fracture energy regularization for the numerical modelling of concrete structures with recycled aggregate: An application with an UMAT user subroutine for ABAQUS","volume":"148","author":"Zitouni","year":"2025","journal-title":"Mech. Res. Commun."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"110570","DOI":"10.1016\/j.ijmecsci.2025.110570","article-title":"Mesoscale modelling of triaxial concrete fracture: The role of aggregate shapes","volume":"302","author":"Liu","year":"2025","journal-title":"Int. J. Mech. Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"105792","DOI":"10.1016\/j.istruc.2023.105792","article-title":"Experimental and numerical investigation of steel fiber concrete fracture energy","volume":"59","author":"Rashidi","year":"2024","journal-title":"Structures"},{"key":"ref_15","first-page":"135176","article-title":"Numerical study on the effect of steel fibers on fracture and size effect in concrete beams","volume":"211","author":"Yadav","year":"2023","journal-title":"Mater. Today Proc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"109150","DOI":"10.1016\/j.engfracmech.2023.109150","article-title":"Influence of end friction confinement on dynamic mechanical properties and damage evolution of concrete by coupled DEM-FDM method","volume":"281","author":"Zhou","year":"2023","journal-title":"Eng. Fract. Mech."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"110816","DOI":"10.1016\/j.engfracmech.2025.110816","article-title":"Numerical study on dynamic fracture of rock-concrete bi-material Brazilian disks with a central interface crack","volume":"315","author":"Zhou","year":"2025","journal-title":"Eng. Fract. Mech."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"128885","DOI":"10.1016\/j.conbuildmat.2022.128885","article-title":"Coupled. FDM-DEM simulations of axial compression tests on FRP-confined concrete specimens","volume":"351","author":"Wu","year":"2022","journal-title":"Constr. Build. Mater."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"110887","DOI":"10.1016\/j.jobe.2024.110887","article-title":"Fracture performance of concrete-epoxy mortar interface subjected to bending and shear: Experimental and numerical study","volume":"97","author":"Hang","year":"2024","journal-title":"J. Build. Eng."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"107822","DOI":"10.1016\/j.compstruc.2025.107822","article-title":"3D-printed concrete fracture: Effects of cohesive laws, mixes, and print parameters in 3D extended FEM","volume":"315","author":"Mukhtar","year":"2025","journal-title":"Comput. Struct."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"104216","DOI":"10.1016\/j.tafmec.2023.104216","article-title":"Meso-crack propagation process of concrete based on macro-fracture parameters: Numerical and experimental","volume":"129","author":"Zeng","year":"2024","journal-title":"Theor. Appl. Fract. Mech."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"132990","DOI":"10.1016\/j.conbuildmat.2023.132990","article-title":"Low-temperature fracture behavior of railway asphalt concretes under semi-circular bending: Experimental and numerical investigation","volume":"402","author":"Xiao","year":"2023","journal-title":"Constr. Build. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.commatsci.2012.05.009","article-title":"Numerical modelling crack propagation under Mode II fracture in plain concretes containing siliceous fly-ash additive using XFEM method","volume":"62","author":"Golewski","year":"2012","journal-title":"Comput. Mater. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"137386","DOI":"10.1016\/j.jclepro.2023.137386","article-title":"Experimental and numerical investigation on fracture characteristics of self-compacting concrete mixed with waste rubber particles","volume":"412","author":"Zhu","year":"2023","journal-title":"J. Clean. Prod."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"108395","DOI":"10.1016\/j.compositesa.2024.108395","article-title":"Effects of recycled aggregates on mechanical and fractural properties of concrete: Insights from DEM modelling","volume":"186","author":"Zhao","year":"2024","journal-title":"Compos. Part A"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"117580","DOI":"10.1016\/j.conbuildmat.2019.117580","article-title":"Using random heterogeneous DEM model to simulate the SCB fracture behavior of asphalt concrete","volume":"236","author":"Xue","year":"2020","journal-title":"Constr. Build. Mater."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"110153","DOI":"10.1016\/j.engfracmech.2024.110153","article-title":"Mesoscopic. simulations of a fracture process in reinforced concrete beam in bending using a 2D coupled DEM\/micro-CT approach","volume":"304","author":"Nitka","year":"2024","journal-title":"Eng. Fract. Mech."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.cemconres.2018.02.006","article-title":"three-dimensional meso-scale approach to concrete fracture based on combined DEM with X-ray \u03bcCT images","volume":"107","author":"Nitka","year":"2018","journal-title":"Cem. Concr. Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.engfracmech.2015.08.010","article-title":"Modelling of concrete fracture at aggregate level using FEM and DEM based on X-ray \u03bcCT images of internal structure","volume":"147","author":"Nitka","year":"2015","journal-title":"Eng. Fract. Mech."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2083","DOI":"10.1177\/14759217211052855","article-title":"Effect of fiber dosage on water permeability using a newly designed apparatus and crack monitoring of steel fiber\u2013reinforced concrete under direct tensile loading","volume":"21","author":"Zahoor","year":"2022","journal-title":"Struct. Health Monit."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"118880","DOI":"10.1016\/j.conbuildmat.2020.118880","article-title":"Mechanism of blended steel slag mortar with CO2 curing exposed to sulfate attack","volume":"251","author":"Chang","year":"2020","journal-title":"Constr. Build. Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1007\/s12583-020-1355-1","article-title":"Petrogenesis and tectonic implications of the Jabal Hadb ad Dayheen granitic complex, central Arabian shield","volume":"34","author":"Tong","year":"2023","journal-title":"J. Earth Sci."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Zhu, Z., Mediamartha, B.M., Yu, S., Li, Y., Xu, J., and Gu, P. (2025). Simulation of the Mesoscale Cracking Processes in Concrete Under Tensile Stress by Discrete Element Method. Materials, 18.","DOI":"10.3390\/ma18132981"}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/22\/5140\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,12]],"date-time":"2025-11-12T11:02:43Z","timestamp":1762945363000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/22\/5140"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,12]]},"references-count":33,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2025,11]]}},"alternative-id":["ma18225140"],"URL":"https:\/\/doi.org\/10.3390\/ma18225140","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,12]]}}}