Crack Development Research Articles

Seismic Performance of Ordinary and Damage-tolerant Concrete Beam-column Joints under Reversed Cyclic Loading

The adoption of the capacity design principle in modern codes of practice allows for multi-storey frame structures to exhibit ductile behaviour in a major earthquake without collapsing. Whilst the risk of shear failure in regions of large inelastic deformation can be largely reduced, the detailing requirements in capacity design often leads to reinforcement congestion that adds difficulty during the construction process, due to the high amount of transverse reinforcement required to provide shear resistance and confinement. The work presented in this paper forms a part of a wider research programme that aims to simplify the detailing requirements of transverse reinforcement in the joint and plastic hinge regions of moment-resisting frame structures. To this end, damage-tolerant concrete known as engineered cementitious composite (ECC) was used to substitute concrete in these critical regions. In this article, the results of reversed cyclic tests on two half-scale exterior beam-column joints, constructed with ordinary concrete and ECC, are presented. Key features of the response such as the reversed cyclic hysteresis loops, stiffness degradation and cumulative energy dissipation are discussed, along with crack development under reversed cyclic loading in the form of digital strain maps.

Fatigue stress concentrations analysis of real corroded steel structures based on replica imprints

AbstractThe service life of offshore support structures is significantly reduced by corrosion. In particular, pitting corrosion leads to high local stress concentrations and can reduce the expected fatigue strength. Previous studies on corroded specimens have shown that crack development in fatigue tests is correlated with stress concentration. In the context of maintenance of existing offshore wind turbines, there are novel efforts to capture the real surface geometry of corroded components with the so‐called replica technique, in which an imprint of the surface geometry is made and digitized with a 3D‐scanner and used to numerically analyse the stress concentrations due to pitting corrosion. In this study, it was shown that the replica technique is able to reproduce the effective stress concentrations of the original surface with very high accuracy.

Direct tensile mechanical properties and damage fracture mechanisms of thermally damaged coal measures sandstone under high strain rate loading

The direct tensile mechanical properties of highly thermally damaged rock under high strain rate loads are a key basic mechanical problem that must be solved for the stability and effective control of surrounding rock stability in the combustion control area of an underground coal gasification project. In this paper, a two-dimensional equivalent grain-based model (GBM) unit and Split Hopkinson Tension Bar (SHTB) numerical model for thermally damaged coal-measures sandstone were constructed using particle flow code (PFC). The comparison with the experimental results shows that the numerical method can accurately describe the dynamic direct tensile behavior of thermally damaged sandstone. The following conclusions are drawn: The dynamic tensile strength of thermally damaged sandstone shows a significant strain rate-strengthening effect. With the increase in thermal damage temperature, the dynamic tensile strength of sandstone increases first and then decreases. The generation and development of hot cracks in a high-temperature environment is the fundamental reason for the change in macroscopic mechanical properties. The dynamic tensile failure process of thermally damaged sandstone can be divided into four stages: the dynamic damage initiation, the dynamic damage development, the damage crack penetration, and the sample dynamic fracture. With the increase in impact velocity, the initial kinetic energy, elastic strain energy, dissipated energy, and elastic strain energy ratio in the failure process of thermally damaged sandstone gradually increase. In contrast, the dissipated energy ratio gradually decreases. As the heat treatment temperature increases, the elastic strain energy and the ratio of elastic strain energy increase first and then decrease.

Macroscopic and mesoscopic comparative study of frozen loess under loading and unloading

This paper utilizes computed tomography (CT) real–time observation technology to investigate the damage mechanism of frozen loess under loading and unloading. The intrinsic connections between macroscopic mechanical degradation and mesoscopic damage in frozen loess were established through a comparative analysis of macroscopic mechanical parameters (such as dissipation energy and elastic strain energy) and mesoscopic structural parameters (such as porosity increment and mesoscopic structural damage increment) of frozen loess under loading and unloading. Furthermore, the relationships between damage variables at different scales under the effects of loading and unloading were explored. The experimental results demonstrate that during the elastic strain stage, the dissipated energy, porosity increment, and microscopic damage increment of frozen soil exhibit a linear increase with strain. Following loading and unloading, the porosity is unable to be fully restored to its original state due to the development of new cracks. At this stage, the deformation is not entirely elastic and includes some plastic deformation. During the plastic deformation stage, the dissipated energy tends to stabilize, while the porosity increment and microscopic damage increment continue to increase substantially. The pore structure of a specimen undergoes significant alterations, with increased displacement and rearrangement of soil particles and ongoing expansion of cracks. The damage evolution trends at both the macroscale and mesoscale remain consistent during this stage. This study offers insights into the construction of a cross–scale macroscale/mesoscale ontological damage model, serving as a valuable reference for future research.

Effect of fiber reinforcement on bond behavior between coral aggregate concrete and GFRP bar

The increasing construction activities on islands make FRP reinforced coral aggregate concrete (CAC) more and more promising. However, the poor mechanical performance of CAC reduces the bond properties between CAC and GFRP bars, which poses a threat to engineering safety and long-term service. Therefore, fibers were added as reinforcement in CAC to improve the bond properties. In the present study, the effect of fiber reinforcement on the bond behavior between CAC and GFRP bars was studied by pull-out tests. The mechanical properties of fiber reinforced coral aggregate concrete (FRCAC) were also investigated as a comparison to the bond properties. The microstructure and failure characteristics of the interface between FRCAC and GFRP bars were observed through scanning electron microscopy. The results showed that adding fibers as reinforcement can inhibit the development of cracks in FRCAC and even change the failure mode of bonding specimens from concrete splitting to bar pull-out. The mechanical and bond properties of CAC reinforced by fibers were all improved, although the improvement was not as significant as that observed in traditional normal aggregate concrete. The reinforcing effect was more significant on mechanical properties than on bond properties as the fiber content increased. Among polypropylene fiber, basalt fiber, and copper-surfaced steel fiber, basalt fiber and copper-surfaced steel fiber demonstrated a more significant reinforcing effect on the bond properties between FRCAC and GFRP bar than polypropylene fiber. A calculation method for determining the bond strength between FRCAC and GFRP bar was proposed.

Effect of notch depth ratio and specimen width on mode II fracture properties of ECC

Engineered Cementitious Composites (ECCs) can be used as repair and reinforcement materials, which can improve the shear performance of the structure. Hence, doubled-notched and unnotched half-symmetric loading tests are used to study the mode II fracture properties of ECC and concrete, and the fracture failure morphology and fracture parameters of ECC and concrete are compared. The effects of the notch depth ratios of 0, 0.1, 0.3, and 0.5 and the specimen widths of 200 mm, 250 mm, and 300 mm on the mode II fracture properties of ECC and concrete are investigated. The mode II crack development of ECC can be divided into four stages: microcrack development stage, multiple cracking stage, main crack formation stage, and crack instability development stage. It can be found that ECC not only has high ultimate tensile strain and energy dissipation capacities, but also has obviously better ability to resist the unstable propagation of shear cracks than concrete. ECC can meet the high shear resistance requirements of some parts of the structure.

Evaluation of residual flexural behavior of corroded fiber-reinforced super workable concrete beams

This study investigates the effect of macro synthetic fiber (MSF) volume and crack widths on corrosion of the reinforcing bars and residual flexural behavior of fiber-reinforced super-workable concrete (FR-SWC) beams exposed to accelerated corrosion. FR-SWC beams prepared with 0, 0.33%, and 0.66% MSF were pre-cracked at 0.2-, 0.4-, and 0.75-mm widths before corrosion testing. The controlled crack width was initiated in one set of beams that were then unloaded. The crack width was maintained for another set of beams during corrosion testing by inserting a shim. Test results showed that the use of 0.33% and 0.66% MSF reduced crack development and crack propagation, delayed corrosion initiation time, and significantly increased the residual flexural strength of beams subjected to accelerated corrosion. The beams reinforced with 0.66% MSF enhanced residual ultimate load, residual yield load, and residual flexural toughness by 10%–45%, 38%–113%, and 42%–150% compared to the corresponding non-fibrous beams. The improved flexural performance of beams made with MSF after accelerated corrosion can be attributed to the ability of MSF to reduce crack width due to corrosion damage. Crack width lower than 0.2 mm showed no significant effect on the residual flexural behavior of beams after corrosion testing. However, the pre-crack width over 0.2 mm showed a significant influence on the crack initiation and residual flexural behavior after accelerating corrosion. The pre-cracked beams with a 0.75 mm crack width retained the ultimate load of 65%–76%, yield load of 47%–80%, and toughness of 38%–83%, respectively, compared to their corresponding uncracked beams subjecting to accelerated corrosion. The un-shimmed beams allowed partial closure of cracks due to the presence of MSF after initial loading and increased the residual ultimate load, yield load, and flexural toughness by 7%–45%, 27%–82%, and 3%–56%, respectively, compared to their corresponding shimmed beams. A correlation between the residual flexural behavior and the rate of cross-sectional area loss of reinforcing bars due to corrosion was developed. Furthermore, a mechanism was proposed to explain the effect of MSF in improving the residual flexural performance in the cracked FR-SWC beams.

Experimental evaluation of mechanical properties and microstructure for recycled aggregate concrete collaboratively modified with nano-silica and mixed fibers

The present study was conducted to meet the demand of the construction schedule for emergency repair and construction in special projects by using the recycled aggregates produced by mechanically crushing the demolished materials on-site. The study aims to modify recycled aggregate concrete (RAC) by incorporating silica nanoparticles (NS) and mixed fibers together to meet the needs of the above special project. Here, the properties of 21 kinds of concrete with different NS contents and mixed proportions of fibers were tested, including their fresh properties, hardening properties and microstructure. Their working properties in the fresh state were studied by measuring slump and unit weight; while the mechanical properties after hardening were mainly evaluated in terms of compressive strength, splitting tensile strength, modulus of elasticity and flexural strength, and here the flexural toughness as well as the residual strength of the specimens were calculated using two methods. In addition, the effects of different NS contents, steel fibers and polyvinyl alcohol (PVA) fibers on crack development and water absorption were investigated in the microstructure. The pores between the cement matrix, interfacial transition zone (ITZ) and fibers and how they are alteredby NS were characterized by SEM and 3D-CT scans. All these results indicate that NS content has a significant effect on both the workability and mechanical properties of RAC, that steel fibers are beneficial to improve the overall mechanical index of RAC, while PVA fibers have a limited enhancement effect, and that NS particles in the microstructure help to fill the pores of 0.001–0.01 mm3 volume in the cement matrix and improve the performance of the ITZ.

Desulfurization steel slag improves the saline-sodic soil quality by replacing sodium ions and affecting soil pore structure

Flue gas desulfurization steel slag (DS), a solid waste produced by coal power plants and steelworks, was proposed as an amendment for the remediation of saline-sodic soil. A pot experiment including three dosages of DS alone (1%, 5%, 10% w/w) and their combination with fulvic acid (FA, 1%, w/w) was conducted to evaluate the potentials of DS as an amendment and to explore remediation mechanism of DS combined with FA on saline-sodic soil. The soil salinity, nutrition, pore structure, water retention, consistency, and desiccation cracking of DS and FA-amended soils were determined. Application of DS resulted in a significant reduction of pH, sodium adsorption ratio (SAR), and exchangeable sodium percentage (ESP) of saline-sodic soil. The DS amendment significantly increased the 6–15 μm pore volume of soil. The combination application of DS and FA showed better effect than the DS alone. The DS amendments at 5% and 10% significantly increased the field water capacity, permanent wilting point, and available water content of the soil, whereas significantly decreased the plastic limit, liquid limit, and plastic index. The DS alone and combined with FA could effectively control the development of desiccation cracking, reduced significantly the crack area density and average width of cracks of the soil. Consequently, the improvement of alkalinity and soil physical properties by DS amendment significantly increased the yield of alfalfa grown on saline-sodic soil. The remarkable improvement of physical properties of saline-sodic soil contributed to the decrease of SAR and ESP by the Ca2+ in DS replacing the Na + at soil colloid sites. Our results suggested that DS amendments alone or combined with fulvic acid have great potential as saline-alkali soil amendment.

Tensile property analysis of carbon/glass hybrid fibers-reinforced graphene-modified polymer bars

The application of single-type fiber-reinforced polymer (single-FRP) bar in civil engineering is restricted due to the brittle failure and low tensile modulus. In this work, the carbon/glass hybrid fibers-reinforced polymer (C/G-HFRP) bars were designed to realize tensile ductility and improve tensile modulus. Also, graphene nanosheets (GNPs) were used to modify the fracture toughness of polymer matrix between fibers, which can resist the energy release rate during the failure of carbon fibers and the crack initiation and development inside the modified C/G-HFRP bars. The experimental results indicated that GNPs increased the cooperative ability between fibers and reduced the separation degree of glass fibers after the failure of carbon fibers. The tensile strength and strain of the modified C/G-HFRP bars at the initial failure of carbon fibers were averagely improved by 6.9% and 4.3% relative to those of the unmodified ones, while their ultimate tensile strength and strain were averagely increased by 7.1% and 7.1%, respectively. Meanwhile, four evaluation indicators were proposed to reflect the superior performance of the modified C/G-HFRP bars. Additionally, the experiments verified that the contribution of carbon fibers to the secondary stiffness at the strain hardening stage in the tensile stress–strain response of the modified C/G-HFRP bars can be omitted.

Interfacial strength characteristics between modified iron tailings and profiled fibers under dry–wet and freeze–thaw environments

The interfacial properties of fibers and matrix materials have an important effect on the mechanical properties of fiber-reinforced materials. To study the role of fiber morphology and the environmental effects on the interfacial properties of fibers and matrix materials, the interfacial strength characteristics of undulation polypropylene fiber (UPF) and serrated polypropylene fiber (SPF) with cement-modified iron tailings (CIT) were analyzed through single-fiber pullout tests. The effects of curing age, freeze–thaw cycles, and dry–wet cycles on interfacial strength were analyzed. The energy dissipation during fiber pullout under different environmental conditions was verified, and the microscopic mechanism of interfacial strength change was determined. The results show the following: (1) The interfacial strength of UPF and SPF is positively correlated with curing age, while freeze–thaw and dry–wet cycles can impair their interfacial properties; also, the interfacial strength decreases substantially and tends to flatten out after 3 cycles. (2) The dissipation energy of UPF and SPF increases with curing age, but decreases as the number of dry–wet cycles and freeze–thaw cycles increases. The critical reinforcement length of UPF is better than that of SPF by 363% and 50% under freeze–thaw and dry–wet cycles, respectively. Also, its performance and reinforcement effect in reducing crack development under freeze–thaw and dry–wet environments are better compared to SPF. (3) The interfacial strength of the profiled fibers consists of adhesion and friction. Freeze–thaw cycles cause a significant damage to adhesion and friction, while dry–wet cycles mainly affect adhesion. Interfacial strength is related to the curvature of the fiber and the unconfined compressive strength of CIT, which follows a linear function.

The influence of microtexture tools on the geometric morphology of serrated chips based on stress triaxiality

PurposeThis study aims to investigate the effect of microtextured tools on the geometric morphology of serrated chips, and further improve the cutting performance of polycrystalline cubic boron nitride (PCBN) tool and extend the tool life and the surface quality of the machined surface.Design/methodology/approachA three-dimensional finite element cutting model of hardened steel AISI D2 with microtextured PCBN tools were established using the finite element software Abaqus, and cutting tests were carried out. Furthermore, the stress distribution in the primary deformation zone was investigated based on the triaxiality of stress, and the influence of microtexture on the geometric morphology of serrated chips and crack development was researched.FindingsThe results show that compared with nontexture tools, elliptical pits and wavy grooves microtexture tools have lower serrated degree Gs, higher serrated frequency f per unit length and more miniature serrated step Pc. The serrated phenomenon is intensified because the tensile stress zone of chips generated by nontextured tools is longer than that of elliptic pits and wavy grooves microtexture tools. Simultaneously, the maximum value of triaxiality in the tensile stress zone achieved by nontexture tools is larger than that of the two microtexture tools, and chips obtained by nontextured tools are more susceptible to propagation fractures.Originality/valueThis paper mainly studies the effect of microtexture on chip microgeometry, which is relatively little studied at present. At the same time, this paper has a certain engineering significance for PCBN tool turning hardening steel.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0149/

Simulation of mechanical properties of HTPB‐based propellant by a viscoelastic spring lattice model

AbstractAn improved lattice spring model extended by viscoelastic part using the Maxwell model was applied to predict the mechanical properties of HTPB‐based solid propellants. The influence of both strain rate and temperature on the maximum elongation of HTPB‐based propellants was quantitatively analyzed by simulating the uniaxial tensile test, as well as the process of crack development during tensile loads. The results show that the maximum elongation of HTPB‐based propellant decreases as a power function along with the linear increase of strain rate. In contrast, the maximum stress increases as a power function. Increasing the temperature linearly, both the maximum stress and the maximum elongation decrease as a power function.

Acoustic emission characteristics of rock salt under multi-stage cyclic loading

Rock salt is a common sedimentary rock found in the crust and is widely used for underground energy storage and waste disposal. This research conducted multi-stage cyclic loading on impure Huai'an rock salt while monitoring acoustic emissions (AE) in real-time. The results show that as the loading stress increases, the cumulative AE energy increases in a stepwise manner. The frequency distribution displays a band pattern of low, medium, and high frequencies. As the loading stress increases, the proportion of high-frequency signals decreases while that of low-frequency signals increases. The proportion of medium-frequency signals remains consistently the highest. The b-value initially decreases and then increases, with a sharp drop near the failure. Compared to the increased lower limit stress (ILLS), the constant lower limit stress (CLLS) causes higher cumulative AE energy and amplitude, and smaller b-values for the salt samples. These results indicate that the CLLS increases the size of cracks and damage in the salt samples. Based on the RA (risetime/ amplitude)-AF (average frequency) distribution, it is found that the primary mode of failure for rock salt under multi-stage cyclic loading is tensile cracking. Compared to the ILLS, the CLLS promotes the development of shear cracks. The AE test results of the rock salt provide an important basis for explaining the in-situ microseismic signals generated during the operation of salt cavern energy storage.

Application of Steel-Fiber-Reinforced Self-Stressing Concrete in Prefabricated Pavement Joints

Prefabricated pavement, with its advantages of a high paving speed, low material consumption, low carbon emissions, high strength, and easy construction, has gradually been used to address issues associated with traditional cement pavement construction. However, even under the long-term combined effects of vehicle loads and environmental loads, the joints between pavement slabs remain prone to various problems. This paper proposes the use of steel-fiber-reinforced self-stressing concrete (SFRSSC) with a certain level of self-stress for joint pouring and connection to control the development of cracks in the joints and achieve seamless integration between the slabs. Additionally, the self-stress generated by SFRSSC is utilized to enhance the continuity of the prestressed design in precast slabs, thereby extending their service life. Through laboratory experiments and field tests, the self-stress magnitude, mechanical strength, and long-term applicability of SFRSSC were studied. The results indicate that SFRSSC can achieve self-stress levels of over 7 MPa under standard curing conditions, but the values decrease significantly when removed from the standard curing environment. SFRSSC exhibits a compressive strength of over 60 MPa and a flexural strength of over 9 MPa, both of which exceed the requirements of the relevant standards, making it suitable for use as a pavement joint material. During long-term monitoring in the field, SFRSSC demonstrates favorable expansion effects and high stability. The longitudinal expansion remains stable at 100 με, while the transverse expansion exhibits minor shrinkage, maintained at around 25.2 με. Therefore, the application of SFRSSC in assembly-type prestressed pavement joints shows high applicability.

Recent Progress in the Cracking Mechanism and Control Measures of Tunnel Lining Cracking under the Freeze–Thaw Cycle

With the rapid increase in the scale and number of tunnels in cold regions, the frost damage problems, such as cracking of the lining structure under the action of freeze–thaw cycles are becoming increasingly prominent. This review article collects and sorts out the frost damage phenomena that occur in the lining structure of tunnels in cold regions under the action of freezing and thawing cycles, classifies the frost damage phenomena into structural frost damage and non-structural frost damage, and proposes that the research on the mechanism of lining frost damage and its prevention measures should focus on lining cracking. According to the damage degree of the freeze–thaw cycle to the lining structure and its influence on tunnel operation, the cracking mode and cracking stage of lining are introduced. The analysis focuses on the mechanism of cracking in lining structures subjected to freeze–thaw cycles, considering the external force caused by frost heaving, the alteration of mechanical properties in lining concrete, and the internal changes in the microstructure of the concrete. Additionally, the factors that contribute to the occurrence of lining cracking are summarized. Based on this, corresponding control measures have been organized to provide reference for the development of cracking of the lining structure under the action of freeze–thaw cycle.

Experimental Study and Finite Element Modelling of Squat Shear Walls under Combined Cyclic Loads and High Axial Loads

Experimental observations on three reinforced concrete shear walls with small shear span-to-depth ratio (SDR) under combined high vertical axial load and horizontal cyclic loads are presented. The influence of high axial load ratio (ALR) on the failure mode, hysteretic behaviour, displacement ductility, shear strength and stiffness of the squat shear walls is investigated. In addition, a novel built-in strain gauges measuring system is employed for measuring the strain conditions in the reinforcements during the whole test process. Test results indicate that high axial load restrains the development of cracks and improves the shear load capacity, but that it also decreases ductility and energy dissipation and aggravates stiffness degradation. Concrete crush and out-of-plane buckling were observed in all specimens, resulting in the final failure of the specimens. According to the strain analysis, the section of the squat walls coincided well with the assumption of plane section under the condition of high ALR. With the increase of ALR, the depth of the compression zone of members increases, while the length of plastic hinge decreases. When the axial load is relatively small, the vertical and horizontal reinforcements provided almost equal contribution to the shear capacity of squat shear walls. However, under extremely high axial load, both vertical and horizontal reinforcements cannot provide full contribution to the shear capacity. The hysteretic behaviours of the tested shear walls were simulated by a cyclic softened membrane model (CSMM). Simulation results indicate that CSMM captured well the nonlinear characteristics of the squat shear wall under high axial load.

Study on Force Characteristics and Safety of Segment Structure and Bolts with and without Cavity behind Lining with Multi-Field Coupling

In this study, a refined three-dimensional stratigraphic–structural model is established based on ABAQUS finite element software, and the basis for determining pneumatic and vibration loads is explained in detail. From this, the force characteristics of the segment and bolts with and without a cavity behind the lining under the action of multi-field coupling were analyzed, and the force law and corresponding safety of the segment structure and high-strength bolts were determined. The results show that the peak value of the maximum principal stress on the segment structure caused by the surrounding rock pressure was 92.7 times greater than the variation in the peak value of the maximum principal stress caused by additional loads (pneumatic and vibration loads). Despite this, the safety factor of the segment structure satisfied the code requirements. Compared to the situation with no cavity behind the lining, when the cavity behind the lining was small the stresses of the segment structure were large and concentrated, which increased the possibility of crack development in the segment structure. The nodal stresses and strains on the straight and bending bolts exhibited an approximately “W”-shaped distribution with a cavity behind the lining. In addition to the effect of the preload near the nut, the stress and strain at the central measurement point of the bolt rod at the joint face were larger owing to the coupling effect of multiple fields. The high-strength bolt remained in an elastic state and did not yield with damage.

Multiscale study of microstructural evolution in alkali-activated fly ash-slag paste at elevated temperatures

To promote the high-temperature application of alkali-activated fly ash-slag (AAFS), it is vital to thoroughly understand the performance of AAFS at elevated temperatures. This paper presents a systematic study on the multiscale microstructural evolution in AAFS paste in terms of nanostructure, chemical composition and morphology changes characterised using 29Si nuclear magnetic resonance, X-ray diffraction and Fourier transform infrared spectroscopy, as well as the pore structure evolution by means of mercury intrusion porosimetry, backscattered electron microscopy and X-ray microcomputed tomography. Results indicate that the decomposition of C-A-S-H and N–C-A-S-H gels occurs while gel pores are filled at elevated temperatures up to 800 °C, along with the crack development, whereas micro-cracks are healed by melting and viscous sintering. This study provides an in-depth insight into the damage mechanisms of AAFS paste at elevated temperatures from a multiscale viewpoint, accounting for Level I: solid gel particles, Level II: gel matrix, and Level III: AAFS paste.

Effect of residual mortar on compressive properties of modeled recycled coarse aggregate concrete

Based on the typical morphology of recycled coarse aggregate in reality and the ontological relationship of the existing recycled aggregate concrete (RAC) mesoscopic constituent materials, a finite element analysis model of recycled coarse aggregate that can take into account the factors of the amount and location of attachment of the residual mortar was developed to establish the Modeled Recycled Coarse Aggregate Concrete (MRCAC). Combined with the mesoscopic mechanical properties of MRCAC, a plastic damage intrinsic model was used in the numerical analysis of MRCAC under uniaxial compressive loading to study the damage characteristics and stress–strain relationships of MRCAC. In this paper, the Modeled Recycled Coarse Aggregate (MRCA) is established in the ABAQUS numerical analysis software by self-compiled Python script, and the uniaxial compression simulation of MRCAC is carried out. Compared with the existing idealized model recycled concrete and other forms of digital recycled concrete model, The results show that, on the premise of meeting the general law of existing research results, the development of cracks in MRCAC under load is directly related to the shape of residual mortar wrapping. The strength of MRCAC is minimally influenced by residual mortar adhesion amount; however, the coverage of residual mortar has a significant impact on its strength. The arrangement of MRCA may also play a role in the stress–strain relationship of MRCAC. Additionally, it should be noted that residual mortar adhesion amount and coverage are distinct concepts that affect the strength and strain of MRCAC independently. These findings highlight the need to differentiate between these two factors in further research.