Crack Development Characteristics Research Articles

Soil-water characteristic curve of expansive soils considering cumulative damage effects of wetting and drying cycles

A novel experimental program was undertaken to explore crack development inside an expansive soil column under cyclic Wetting and Drying (W-D) and its influences on the Soil-Water Characteristic Curve (SWCC). Experimental investigations revealed that in the first drying cycle, fine and evenly distributed cracks developed from initial defects in the upper surface. In the subsequent drying cycles, the unhealed cracks during the wetting cycle further grow in width, length and depth while the initiation zone of new cracks was limited. The crack development characteristics within the soil column were described using fractal dimensions. The cracking degree of soil cross-sections gradually reduced with increasing depth. Also, each W-D cycle process contributed to a similar increment in the crack fractal dimension of soil at the same depth. In addition, the saturated water content, air-entry value and residual suction of cracked expansive soils gradually reduced with an increase in the number of W-D cycles. An obvious bimodal phenomenon was only observed in the SWCC of soil samples after the third W-D cycle. In order to quantify the damage induced by crack development to the soils, the damage variable was proposed based on the crack fractal dimensions. Furthermore, the Damage Impact Factor (DIF), as a function of the volume damage variable and soil plasticity index, was introduced into the traditional Fredlund and Xing (F-X) model to estimate the SWCC of cracked expansive soil. The form of modified F-X model is relatively simple and can be conveniently extended into geotechnical engineering practice applications.

Deformation behavior and damage characteristics of surface buildings induced by undercrossing of shallow large-section loess tunnels

The ground movement during the construction of shallow loess tunnels can easily cause deformation damage to surface buildings. Most the current studies focus on the damage soft soil and rock tunnels to independent buildings, and there are few studies on the case of building groups in loess areas. Using the new Xi’Yan Railway Luochuan Tunnel as a case study, we conducted on-site testing to study building settlement and crack development characteristics. Three-dimensional numerical simulations were carried out to analyze settlement, flexure deformation, and main tensile strain distribution characteristics of the buildings at different buried depths. The study determines the extent of damage resulting from differential settlement and tension cracks. The results show that construction during the upper, middle, and lower bench stages results in significant ground volume loss, leading to a ’wide and steep’ settlement pattern with a maximum settlement value of 567 mm. Building cracks exhibit positive and inverted splayed shapes, with lengths ranging from 0.5 to 6.0 m and widths between 0 to 170 mm. As buried depth increases, maximum settlement, flexure deformation, and main tensile strain of buildings also increase. The severe damage range of buildings initially increases and then stabilizes, with the maximum range caused by differential settlement and tensile cracks being 34 m and 29 m from the tunnel axis, respectively. Based on the analysis of building damage characteristics, it was determined that a combination of surface measures and measures within the tunnel should be used to control building damage caused by tunnel construction. These research findings can serve as valuable references for similar projects.

Mesoscopic Analysis of Fatigue Damage Development in Asphalt Mixture Based on Modified Burgers Contact Algorithm in Discrete Element Modeling.

This study is aimed at examining the mesoscopic mechanical response and crack development characteristics of asphalt mixtures using the three-dimensional discrete element approach via particle flow code (PFC). The material is considered an assembly of three phases of aggregate, mortar, and voids, for which three types of contact are identified and described using a modified Burgers model allowing for bond failure and crack formation at contact. The laboratory splitting test is conducted to determine the contact parameters and to provide the basis for selecting three different load levels used in the indirect tensile fatigue test and simulation. The reliability of the simulation is verified by comparing the fatigue lives and dissipated energies against those from the test. Under cyclic loading, the internal tensile and compressive force chains vary dynamically as a response to the cyclic loading; both are initially concentrated beneath the top loading strip and then extend downward along the loading line. The compressive chains are oriented roughly vertically and develop an elliptic shape as damage grows, while the tensile chains are mostly horizontal and become denser. An analysis based on the histories of the numbers of different contact types indicates that damage mainly originates from bond failures among the aggregate particles and at the aggregate-mortar interfaces. In terms of location, cracking is initiated below the loading point (consistent with observations from the force chains) and propagates downward and laterally, leading to the macrocrack along the vertical diameter. The findings provide a mesoscopic understanding of the fatigue damage initiation and propagation in asphalt mixture.

Experimental study on damage of slope under drying and wetting cycle based on DC electric method.

In order to investigate the seepage law and crack development characteristics of dump slopes, as well as the impact on slope stability during drying and wetting cycles, a simulation test slope system was constructed in a rainfall environment, specifically designed to mimic the engineering conditions of dump slope. The apparent resistivity response formula for the seepage and crack development processes was derived based on the three-phase medium theory of rock-soil bodies and Maxwell's conductivity formula. The geoelectric field characteristics pertaining to slope damage and the corresponding patterns of alteration were comprehensively investigated. The results demonstrate a negative correlation between resistivity and slope water content, with resistivity increasing as cracks develop and decreasing with water infiltration. The progression of crack formation in a rainfall environment on a dump slope can be categorized into three stages: The initial phase involves the saturation of the slope as water content increases. Subsequently, the second phase entails the initiation and expansion of capillary zones, along with the formation of dominant waterways. Lastly, the third phase encompasses the formation and expansion of cracks within the dumping site. The occurrence of sudden changes and abnormal fluctuations in apparent resistivity within a saturated slope signifies the presence of cracks and weak surfaces, leading to gradual and irreversible damage. This phenomenon serves as an indicator of slope damage and can be utilized for the early prediction of slope instability.

Analysis of crack evolution of expansive soil embankment under extreme arid climate

With the increasing impact of global climate change, the frequency of extreme arid climates worldwide is rising. These extreme arid conditions can have adverse effects on expansive soil embankments. In this study, the digital image technology is used to study the crack development characteristics of expansive soil embankments. The findings indicate that the crack development process in expansive soil can be divided into three stages: slow development, rapid development, and stable development. During the drying process, cracks develop differently on the waterward side, the top of the embankment, and the backwater side of the embankment. Initially, cracks appear on the top of the embankment, and their degree of development is the highest in this area. The crack degree on the top of the embankment is approximately 2 to 3 times greater than that on the waterward and backwater sides. Furthermore, longitudinal cracks on the top of the embankment have been analyzed from both macro and micro perspectives. This study is expected to help analyze the underlying formation mechanisms of desiccation cracking-inducing geohazards and access the long-term performance of expansive soil embankments in arid climates.

Insight into the crack characteristics and mechanisms of retrogressive slope failures: A large-scale model test

Cracks in the crown area are one of the important indicators in the instability of the landslide headscarp, potentially offering early warnings for landslide hazards. Due to the complex causes of crack formation and numerous influencing factors, the understanding of crack development characteristics is still insufficient. In this paper, a large-scale soil slope model test is carried out through a large tilting platform to simulate the whole process of retrogressive slope failures including the first-time failure and the enlargement of the failure. The characteristics of crack development, the relations between internal slope parameters (e.g., internal strain and earth pressure) and cracks, and the evolutionary mechanisms of retrogressive failures are focused. The model test is monitored by high-tech equipment, including optical fibres, pressure gauges, and cameras. The results show that crack developments are divided into four stages based on crack location, quantity, and size. Optical fibre monitoring shows that the areas of tension crack development fall within the negative strain area in the slope model. In addition, the failure mode of the retrogressive landslides can be summarized in three stages: a deformation stage with sparse local cracks, a destabilizing stage with main cracks, and a retrogressive failure stage with dense secondary cracks. This study offers preliminary insights into the relations between crack development and the mechanisms in soil multiple retrogressive failures, which can be beneficial for better identifying and interpreting landslides at sites through crack monitoring.

Investigation on bond performance of concrete strengthened with CFRP plates

In this paper, concrete specimens with type I prefabricated cracks were prepared, and three-point bending tests were used to investigate the influence of parameters, such as carbon fiber reinforced polymer (CFRP) plate thickness, depth of the prefabricated crack, concrete strength, and loading speed, on the bonding performance of reinforced concrete structures with externally attached CFRP plates. The CCD cameras were used as the observation system, and the digital speckle technology is used to analyze the expansion characteristics of the prefabricated crack. The failure mode and crack development characteristics of the specimen are numerically simulated by finite element software. The results show that the reinforcement with externally attached CFRP plates can increase the flexural stiffness of concrete, significantly improve the flexural bearing capacity of concrete, and delay the development of cracks; under the same load, reinforcement with externally attached CFRP plates can reduce the propagation distance of prefabricated cracks and increase the bending deformation displacement of the specimen. The numerical simulation results show that, with the increase in the pasting length of the CFRP plate, the bearing capacity of the specimen gradually increases, the deformation capacity of the specimen gradually increases, and the failure crack moves from the middle to both sides.

Study on the mechanical properties of unloading damaged sandstone under cyclic loading and unloading

To reveal the mechanical properties of rocks under stress disturbance and unloading confining pressure, conventional triaxial compression tests, triaxial compression tests on unloading damaged sandstone, and cyclic loading and unloading tests on unloading damaged sandstone were conducted. Then, the evolutionary characteristics of dissipated energy in sandstone under cyclic loading and unloading were explored, and damage variables were proposed. The crack development characteristics were analyzed from a microscopic perspective. The study results reveal that: (1) the sandstone exhibits obvious brittle failure under different stress paths, and the macroscopic failure mode is dominated by shear failure. As the number of cycles increases, the load-bearing capacity, elastic modulus, and deformation modulus of the sandstone will be significantly reduced if it suffers greater unloading damage. (2) The cyclic action in the early stage inhibits the development of the internal fracture. However, the inhibitory effect is significantly reduced for specimens with larger unloading quantities. The damage variable in the cyclic loading and unloading is about 50.00% of that in the unloading, indicating that unloading confining pressure is the dominant factor for specimen failure. (3) The extension of microcracks within the sandstone is dominated by intergranular cracks, and the number of cracks increases with the increase of unloading quantity. After cyclic loading and unloading, the structure becomes looser. The test results deepen the understanding of rock mechanical behavior and fracture evolution under cyclic loading and can provide a basis for structural stability improvement under stress disturbance and unloading confining pressure.

Energy evolution and crack development characteristics of sandstone under freeze-thaw cycles by digital image correlation.

Freeze-thaw erosion is the main reason for rock mass instability in cold regions and poses major threats to public safety. In this study, the stress threshold, energy, and strain field evolution of sandstone and the variation in stress intensity factor of fractures in various stress fields were all investigated after freeze-thaw cycles by uniaxial compression tests and digital image correlation technology. The results show that the elastic modulus, crack initiation stress, and peak stress all fell by 97%, 92.5%, and 89.9%, respectively, as the number of freeze-thaw cycles approaches 80. Elastic energy's storage capacity also dropped from 0.85 to 0.17. Sandstone's strain was increased by freeze-thaw erosion, which also improved ductility and shortened the cracking time. The stress intensity factor at the crack tip was positively correlated with the tip inclination angle and negatively correlated with the number of freeze-thaw cycles. This study provides a useful reference for understanding the stability of rock masses and the characteristics of crack derivation in cold regions.

Sparse-view CT reconstruction method for in-situ non-destructive testing of reinforced concrete

ABSTRACT X-ray CT is an important in-situ non-destructive testing method that plays an important role in both production and materials research. In-situ CT of concrete can acquire images of concrete slices in the state of holding force loading, which is meaningful for the study of concrete crack development characteristics. However, existing X-ray CT equipment either cannot penetrate large reinforced concrete due to energy limitations or does not address the extremely sparse angular reconstruction problem associated with in-situ testing. In this paper, a sinogram Transformer method based on a priori projection data is proposed to solve this extremely sparse data complementation problem on a large-scale electron accelerator X-ray in-situ CT system. The simulated concrete sparse-view projection data and the full projection data are used as the input and label of the proposed method in order to experiment the method. The results demonstrate the feasibility of using a priori projected sine diagrams with ultra-sparse sine diagram residuals to track sine diagram variation, and verify that structures such as cracks and reinforcement, which dominate the deformation residuals of sinograms in concrete sections, can also be successfully recovered using Transformer in the ultra-sparse view projection of views 4–8.

Identification of damage mechanisms of polymer-concrete in direct shearing tests by acoustic emission

• The damage characteristics of the polymer-concrete interface were recorded by the AE technique. • AE ringing counts and amplitude can effectively detect the first occurrence of cracks. • Generation of new cracks in the interface of polymer and concrete causes high AE activity. • The statistical damage constitutive models using AE parameters were established. As a new type of trenchless material, non-water reacting grouting polymer has been widely used in the reinforcement and trenchless rehabilitation of concrete infrastructure construction. Understanding the interfacial properties of the polymer-concrete composite structure is of great significance for assessing the serviceability and stability of concrete structures. In this paper, the acoustic emission (AE) technique was applied to monitor the interface damage and reveal the interface failure mechanism of polymer-concrete composite specimens. Direct shear tests were performed on polymer-concrete specimens with different polymer densities, and the AE technique was used to monitor the damage process. Various AE statistical parameters, such as AE ringing counts, energy, amplitude distribution, frequency and b-value, were analyzed. With the Weibull random distribution assumption, statistical damage constitutive models using AE parameters were established. The results reveal that AE events existed throughout the whole failure testing process and were the most significant in the yield stage. The interfacial damage of polymer-concrete specimens could be qualitatively predicted by the sharp increase in the accumulated AE ringing count and energy; the overall b-value of the polymer-concrete specimens with different polymer densities was the same and had a similar trend of a rapid decrease in the yield stage. In addition, the damage variable based on AE parameters can be used to better characterize the interfacial cracking process. The present study indicates that the AE technique is an effective technique in capturing crack development characteristics of polymer-concrete composite structures.

Instability Mode and Control Technology of Surrounding Rock in Composite Roof Coal Roadway under Multiple Dynamic Pressure Disturbances

In view of the problems of composite roof coal roadway under multiple dynamic pressure disturbances such as strong stratification, large deformation of the roadway surrounding rock, and poor safety and reliability, this paper analyzed the deformation and instability characteristics of composite roof coal roadway under different influencing factors using numerical simulation and expounded the stress distribution pattern of composite roof coal roadway under multiple dynamic pressure disturbances. The geological conditions of gas control roadway in the 22301 working face of Tunlan coal mine are taken as examples, and this study is carried out based on the analysis of roof instability conditions of composite roof coal roadway. The progressive crack development characteristics in composite roof coal roadway and the instability failure mode of surrounding rock under multiple dynamic pressure disturbances were revealed, and the control mechanism and support scheme were put forward. According to the result, it is difficult to form a stable bearing rock beam due to the occurrence characteristics of the weak interlayer of the composite roof. The deflection of the roadway roof and the extent of the plastic zone are negatively correlated with the distance from the soft rock layer to the roadway but positively correlated with the thickness of the soft rock layer. As the lateral pressure coefficient λ increases, the plastic zone of the roadway surrounding rock first decreases and then increases. With the increasing influence of dynamic pressure, the coal roadway with composite roof suffers from greater damage under the superposition of high ground stress, lateral abutment pressure, and advance abutment pressure, which is characterized by significant zonal failure of the roof and asymmetric failure of surrounding rock. The control method of high-strength thick anchorage + differential support can construct the thick layer stable rock beam of the roof and equivalent support of the side, realizing continuous stress transfer and geometrically coordinated deformation. The support scheme was finally applied to the on-site industrial test, and the mine pressure monitoring results showed that the deformation of the roadway surrounding rock was effectively controlled under the new support scheme.

Durability Investigation of Fiber-Reinforced Functionally Graded Concretes in Cold Regions

Introducing the differential design concept of functional gradient into mass concrete structures is a feasible design concept that can meet the requirement of crack resistance and internal hydration heat reduction for mass concrete in cold regions. This study analyzed functionally graded concrete’s long-term performance and durability behavior through experimental tests. Based on various concrete mix proportion designs, six concrete groups were selected to test. The shrinkage performance tests were conducted according to the specifications, and early crack resistance tests were also carried out. In addition, the crack development characteristics of concrete with different mix proportions were compared and analyzed, and the impermeability, frost resistance, and carbonation resistance tests were conducted. The test results show that concrete’s long-term performance and durability can be effectively improved by adopting the functional gradient concrete design. The functional gradient concrete adds an anti-freezing polycarboxylate superplasticizer, steel fiber, and polypropylene fiber. Therefore, it can better meet the actual needs of mass concrete structures in cold regions. The drying and autogenous shrinkage rates of mass concrete structures mixed with a composite water reducer were significantly reduced. As a result, this method effectively improved the microporous structure, reduced the loss of dynamic elastic modulus, and improved the anti-freezing performance of concrete of various strength grades. Furthermore, adding steel-like fiber and monofilament polypropylene fiber to the concrete outside the structure can improve the crack resistance of concrete and effectively inhibit the occurrence and development of dry shrinkage and early cracks. Therefore, it can better meet the actual needs of mass concrete structures in cold areas.

Impact resistance of concrete pavement surface reinforced with fibre mesh

ABSTRACT The surface layer of military airfield pavements is prone to damage, including cracking, abrasion, and spalling. It is proposed to strengthen the pavement mortar layer by laying fiber mesh to solve these issues. In this study, three meshes of carbon fiber, aramid fiber, and basalt fiber were selected for surface reinforcement across six pavement slabs of 1.5m (length) × 1.5m (width) × 0.25m (height). The drop hammer impact test was carried out on the six pavement slabs. The test data were analyzed using impact times, crack development characteristics, and development models on the surface deflection as evaluation indices. The results show that the fiber mesh can effectively improve the impact resistance of concrete pavement slabs. Aramid fiber mesh best strengthened the pavement surface, whereas the basalt fiber mesh had the least strengthening effect. However, the mesh size has a negligible influence on the impact resistance of concrete pavement slabs. The effect of fiber mesh on improving the impact resistance of the concrete pavement slab corner was greater than that of the concrete pavement slab edge midpoint. Considering the performance and cost indicators, within the scope of the study, aramid fiber mesh is the most suitable for surface strengthening of airfield concrete pavement.

Mechanical Mechanism Analysis of Roof Fracture Evolution in Stope with Variable Length Based on Elastic-Plastic Structure Theory

Stope with variable length is formed by length change of mining face due to the irregular distribution of geological rock pillars, which is a typical representative of complex coal seam mining. According to the geometric characteristics and mechanical boundaries of each mining stage of stope with variable length, the roof structure models with four boundary conditions were established and solved successively by using the small deflection thin plate bending theory. Combined with the simulated images of MATLAB and FLAC3D, the fracture laws and corresponding engineering phenomena were analyzed. According to the characteristics of roof rock pressure zoning, the overburden structure pressure model of “three stopes, three areas, and three structures” is constructed. The research shows that the traditional “O-X” fracture occurs in the roof of small mining stope. For the cracks generated by prolonged “O-X” fracture and drift “O-X” fracture in mutative mining stope are similar to the crack development characteristics of large mining stope, so they are integrated into full-scale mining stope. The full-scale mining stope roof is broken in “X-O” shape, and the crack continues to develop to produce extended fracture, forming the roof fracture theory of “two stopes and two laws.” The research conclusion strongly reveals the failure law of roof from tension instability to plastic fracture and abnormal ground pressure during mining in stope with variable length. It provides a basis for exploring the essence of overburden migration in stope with variable length and strengthening the roof prevention and control theory under the occurrence conditions of deep complex coal seams.

Experimental and Numerical Analysis of Rock Burst Tendency and Crack Development Characteristics of Tianhu Granite

Rock burst is a serious nonlinear dynamic geological hazard in underground engineering construction. In this paper, a true triaxial unloading rock burst experiment and numerical simulation are carried out on Tianhu granite to investigate the rock burst tendency and crack development characteristics of surrounding rock after excavation. The experiment and numerical simulation process monitored the rock burst stress path to determine the rock burst stress. According to the evolution law of the frequency and amplitude of rock burst acoustic emission monitoring, the shape characteristics of rock burst fragments are analyzed. The rock burst numerical simulation analysis is carried out by the PFC software, and the temporal and spatial evolution law of cracks is obtained. The research results show that the laboratory experiment and numerical simulation of Tianhu granite have rock burst strengths of 163.4 MPa and 161 MPa, respectively, and the average rock burst stress ratio is 8.38, that is, the Tianhu granite has a low rock burst tendency. During the rock burst, the development of tensile cracks will produce flaky debris, and the development of shear cracks will produce lumpy debris. Rock burst will happen when the crack growth rate to be exceeded the unloading crack growth rate; therefore, it can be used as a precursor signal for the occurrence of rock burst.

Identification of crack development in granite under triaxial compression based on the acoustic emission signal

To explore the development mechanism of cracks in the process of rock failure, triaxial compression tests with simultaneous acoustic emission monitoring were performed on granite specimens using the MTS rock mechanics test system. The frequency-domain information of the acoustic emission signal was obtained by the fast Fourier transform. The Gutenberg–Richter law was used to calculate the acoustic emission signals and obtain the b-value dynamic curve in the loading process. Combined with the stiffness curve of granite specimens and acoustic emission signal in the time domain and frequency domain, the crack development characteristics in different stages were analyzed. The results showed that the acoustic emission signals of granite samples under triaxial compression can be divided into four stages: quiet period 1, active stage 1, quiet period 2, and active stage 2. b-value attained its maximum value in the active phase 2 when it is close to the sample loss, and then drops rapidly, which means the propagation of cracks and the formation of large cracks. The acoustic emission signal’s dominant frequency was not more than 500 kHz, mostly concentrated in the medium-frequency band (100–200 kHz), which accounted for more than 80%. The proportion of signals in each frequency band can reflect the distribution of the three kinds of cracks, while the change in low-frequency signals can reflect the breakthrough of microcracks and the formation time of macrocracks in granite samples. By fully analyzing the characteristics of acoustic emission signals in the time domain and frequency domain, the time and conditions of producing large cracks can be determined accurately and efficiently.

Numerical modelling of the crack-pore interaction and damage evolution behaviour of rocklike materials with pre-existing cracks and pores

The combined effect of pre-existing cracks and pores on the damage evolution behaviour and mechanical properties of rocklike materials under uniaxial compression was numerically studied. Simulations of cracks and pores alone showed that increasing crack length and pore diameter decrease uniaxial compressive strength (UCS) and elastic modulus. Subsequent simulations considered two types of combinations of pre-existing cracks and pores – two cracks either side of a centric pore, and two pores either side of a centric crack – and the distance between cracks and pores was changed. In the case of two cracks at either side of the pore, UCS increased only slightly when the distance between the cracks and pore was increased. This was attributed to the more profound effect of the presence of the pore on UCS, and was confirmed by the progressive crack development characteristics and the major principal stress distribution patterns, which showed that the cracks initiated from the tips of the two pre-existing cracks made little or no contribution to the ultimate macroscopic failure. In contrast, models with two pores at either side of a centric crack showed a marked dependency of UCS on the distance between the pores and the crack. Cracks propagating from pre-existing pores made a greater contribution to the ultimate macroscopic failure when the pores were close to the centric crack and the effect gradually diminished with increasing space between pre-existing pores and the centric crack. Major principal stress distributions showed an asymmetric mobilisation of compressive stresses at the right and left sides of the two pores, favouring macroscopic shear failure when they were close to the centric crack which had led to a lower UCS. Overall, this study presents some critical insights into crack-pore interaction behaviour and the resulting mechanical response of rocklike materials to assist with the design of rock structures.

Experimental and numerical study on crack development characteristics between two cavities in rock-like material under uniaxial compression

The understanding of failure mechanisms of rocks containing multiple cavities is important for stability assessment of rock excavations in rock engineering applications. However, published research is still limited on the failure mechanism between cavities and quantitative assessment of the crack development characteristics for different cavity configurations. In this research, specimens containing two cavities were investigated for their displacement characteristics and failure mechanisms under uniaxial compression. Digital image correlation (DIC) was used to measure the displacements of the specimens in experiments, while the failure process was modelled using the Particle Flow Code (PFC) software. A density-based clustering method was used to detect micro-crack clusters and the well-known statistical tool of Principal Component Analysis (PCA) was applied innovatively in this work to define the macro-cracks. The clustering method was further developed in this work for vector analysis so that the displacement vectors around macro-cracks could be classified into different types based on the failure mechanism to understand the crack development characteristics. The crack development between two cavities and failure mechanism for different geometrical configurations were subsequently studied in detail using experimental and numerical results.

Crack resistance investigation of mixtures with reclaimed SBS modified asphalt pavement using the SCB and DSCT tests

An investigation for crack resistance of hot mix asphalt (HMA) with reclaimed SBS modified asphalt pavement (RAP-SBS) by semi-circular bending (SCB) test was conducted. The effect of RAP-SBS content and rejuvenating agent (RA) on crack resistance of recycled mixture was analyzed at medium and low temperature. Meanwhile, the horizontal strain field at crack tip and crack development characteristics of recycled mixture were analyzed by digital speckle correlation technique (DSCT). Besides, the effects of long term aging (LOTA) and freeze–thaw (F-T) cycles on the crack resistance were also analyzed. The results show that crack resistance of recycled mixture decreases in accordance with the quadratic polynomial as RAP-SBS content increases at medium and low temperature, regardless of RA. RA can significantly improve the crack resistance of mixture with high content of RAP-SBS, when RAP-SBS content is 30%, the crack resistance is close to that of virgin mixture, but the anti-aging property is poor. The mortar of recycled mixture is easy to form a weak interface, and RA can prolong the cracking time, and the horizontal strain peak at crack tip is also increased. The influence degrees of crack resistance are shown in the order from temperature, RAP-SBS content to LOTA. As RAP-SBS content increases, the sensitivity of the low temperature crack resistance to the F-T cycle increases. The exponential fitting model can express the relationship between crack resistance and F-T cycles, and the damage degree of crack resistance contains rapid damage stages and stable damage stages as F-T cycles increased.