Splitting Failure Research Articles

Development length and bond behavior of lap-spliced reinforcement in Ultra-high performance concrete beams

Ultra-high performance concrete (UHPC) is a new composite material that can significantly improve bond performance with steel bars. There is insufficient research on UHPC bond behavior under actual stress within structural members, which is critical for structure safety and economy. In this paper, 17 lap-spliced beams were tested to simulate flexural member bond conditions. The test parameters included UHPC compressive strength, cover depth, fiber content, splice length and stirrups in the spliced region. All specimens failed by the UHPC cover splitting crack. The beam without fiber experienced brittle splitting failure, while the beams with fibers experienced ductile splitting failure. The test results showed that increasing UHPC strength and cover depth could increase bond strength. The bond strength increased linearly with fiber content from 0% to 3% but decreased with 4% fiber content. Bond strength decreased linearly with splice length. Transverse reinforcement in the lap splice effectively improved bond strength; however, when the additional confinement reaches a limit, the increase in stirrups no longer improves UHPC bond stress. The experimental study established a formula for predicting UHPC bond splitting strength, considering the influence of the above parameters. The maximum limit of bond strength contributed by the stirrup was obtained. Finally, the development length calculation model applicable to UHPC was established by modifying the NC theory method. The proposed model was compared with current design methods, and the predicted values of the proposed model were closest to the experimental values.

Particle flow simulation of Brazilian splitting failure characteristics of layered shale

Shale reservoir is the research hotspot in the development of unconventional oil and gas resources. The properties of bedding plane have an important influence on the mechanical behavior of shale. According to the fracture characteristics of layered shale under Brazilian splitting load, the effects of bedding angle, bond strength ratio and natural fractures on the tensile strength and fracture pattern of layered shale in Brazilian splitting test were studied by particle flow code. The evolution mechanism of meso–macro fracture of shale is analyzed by combining the dynamic change process of particle mesoscopic force chain and crack. The results show that three types of fracture patterns are observed: splitting tensile failure of shale matrix, splitting tensile failure along bedding plane and tensile–shear composite failure along shale matrix and bedding plane. Mesoscopic cracks initiate at the top and bottom loading points of the disk. After the peak load, mesoscopic cracks propagate through and appear dense force chains until macroscopic failure occurs. The bond strength ratio of bedding plane affects the failure pattern and peak strength of the specimen. With the increase in bedding angle, the tensile strength decreases gradually. Considering the influence of natural fractures, the tensile strength of shale is lower, and the crack propagation is more complex. The research model and results provide theoretical basis for the mechanical properties evaluation and fracture pattern analysis of shale.

Research on the bond‐slip behavior and constitutive relationship between I‐shaped steel and shotcrete in tunnel

AbstractThe failure of the initial support of the tunnel caused by the synergistic deformation of steel and shotcrete under high‐ground stress is expected to be solved by arranging studs and steel webs to enhance the structure's bearing capacity. Hence, the bond‐slip mechanism of steel shotcrete with or without studs is unclear. This study aims to determine the bond behavior of the interface between the steel and shotcrete composite structure for tunnel support. The findings of push‐out experiments demonstrate that shotcrete on steel flange longitudinal splitting failure is the failure mode of natural bonding specimens. Tensile failure and expansion failure under the effect of studs is the failure mechanisms of stud steel‐sprayed concrete specimens. Furthermore, experimental data and a mathematical model establish the bond‐slip constitutive law of natural bonding and stud specimens. Finally, in addition to providing a theoretical foundation for the research of bond‐slip, the constitutive model put forward in this paper also supports the prevention of initial support failure in tunnel engineering.

Advanced Prediction for Cyclic Bending Behavior of RC Columns Based on the Idealization of Reinforcement of Bond Properties

The bonding characteristics between steel bars and concrete in reinforced concrete (RC) structures are crucial for the prediction of load-bearing capacity for seismic design. Nevertheless, most previous studies on bond-slip performance focus on the bond strength based on the pull-out experiments, it is often overlooked that the effect on the failure modes of RC members and the deformation performance due to the bond characteristics. In this research, the effect of the diameter and its arrangement of the reinforcement of the RC column on the bond failure mode and load-bearing capacity based on the cyclic loading tests and the FE analysis are carried out. In the cyclic loading test, it was found that two RC columns with different diameters and reinforcement arrangements showed distinct load-bearing capacity, deformation performance, and failure mode. Despite those columns having the same longitudinal reinforcement ratios. In addition, by applying an advanced finite element analysis using a bond-slip model that induces splitting failure, we succeeded in reproducing the cyclic deformation behavior and local damage obtained in experiments with high accuracy. The proposed model brings in the advanced prediction of the seismic behavior of RC structures and the enhancement of seismic resistance of social infrastructure facilities to earthquake disasters.

Damage characteristics of weak rocks with different dip angles during creep

To investigate the influence of the weak layer dip angle on the creep rupture of the composite rock mass, this paper conducts a graded loading creep experiment on the composite rock mass with different dip angles using the acoustic emission method to examine the fracture evolution process. With increasing load grade, the cumulative total ring count of the rock mass shows a “U”-shaped trend, and the acoustic emission spatial positioning results show that acoustic emission events in the rock mass fracture process are primarily concentrated in the vicinity of the weak layer, while events in other areas are few and dispersed. For rock masses with weak layer dip angles of 0° and 15°, cracks occur in both soft and hard rocks, where shear cracks are dominant in soft rocks, tensile cracks are dominant in hard rocks, and finally, the rock mass mainly exhibits tensile splitting failure. For rock masses with weak layer dip angles of 30° and 45°, most of the cracks exist in the interior of the soft rock, which is dominated by shear cracks. With increasing graded loads, the shear cracks continue to develop along the direction of the weak layer, the upper rock mass keeps slipping and dislocating, and the final failure mode is mainly shear-slip failure. The damage evolution varies with the inclination angle of the weak layer, which can be divided into three stages: initial damage accumulation, damage acceleration, and damage destruction. This demonstrates the ability to predict, prevent, and control the occurrence of creep disasters in rock masses with weak layers.

Bond performance of reinforcing bars in SFRC: Experiments and meso-mechanical model

The bond performance of reinforcing bars in steel fiber-reinforced concrete (SFRC) remains a topic of discussion in the community. The effect of deformed steel fiber types is not fully understood, and a rational mechanics-based model is required to consider this behavior. This study experimentally investigated the bond performance of steel rebars in SFRC containing milled-cut (M) fibers with proven high bridging capacity, namely MCSFRC. The results indicated that M fibers yielded a higher bond strength of rebars compared to hook-end (H), crimped (C), and straight (S) fibers from previous studies. This was attributed to the superior bond resistance of M fibers in the matrix, provided by the rough inner surface, stiff end hook, and longitudinal twist. A meso-mechanical model (rib and fiber scale) was then developed to effectively assess the bond strength of rebars in SFRC, accounting for rib-concrete interaction, as well as the fiber reinforcement differences including fiber–matrix interaction, fiber spatial distribution, content, and dimension. This model was applicable to rebars in SFRC with H, C, S, and M fibers, and the results showed good agreement with 301 tests in the established database. On that basis, a unified local bond-slip model for rebars in SFRC was proposed, which was able to suitably reproduce the entire bond-slip response under pull-out and splitting failures.

Failure Behavior and Failure Locations of Oxytenanthera Abyssinica Bamboo Culms under Bending Load

Bending failure modes in solid stem wood and solid culm bamboo varies depending on material and geometric properties. Solid culm cross-sections of Oxythenantera Abyssinica round bamboo resemble to wood, but are anatomically different in their mode of growth and tissue organization. The bending stress gradient and failure behavior has highly related with the culm internal voids termed as hollowness which depends on age of bamboo. Hollowness (k) refers the relative proportion of void volume to solid volume with in a culm. Full culm beam specimens with length of 3.5 m were subjected to bending under 4-point static loading according to ISO 22155. Pattern of vertical deflection varies depending on the maturity of the culm. A statistical and experimental results showed that, for K values between 12-15% a mixed mode of local buckling with a longitudinal shear splitting failure mode was resulted in 4-year age bamboo specimens with a slight (14 mm) shift from the shear center inducing large vertical deflection (142 mm) at midspan. A kink buckle and green stick modes were observed in 2-year and 3-year ages culms at failure point of 124 and 158mm at length ‘L’ (L/2.5 to L/4.5) from shear center with a k value 25-27% and 18-22% respectively.

Modeling red-light running behavior using high-resolution event-based data: a finite mixture modeling approach

To effectively reduce the number of red-light violations and crashes, it is crucial to explore RLR behavior at local intersections, understand the contributing factors, and identify the riskiest intersections by estimating RLR frequency. In this study, a finite mixture modeling method was utilized to understand the contributing factors to RLR behavior and estimate this violating behavior. To develop the RLR estimation models, performance metrics and signal phasing data were collected from the Automated Traffic Signal Performance Measures (ATSPMs) system in two jurisdictions in Arizona: Pima County and the Town of Marana. The results from calibrated models showed that an increase in traffic flow, intersection delay, number of approach lanes, and split failure is associated with an increase in the likelihood of observing red-light violations. In addition, it was found that an increase in cycle length is associated with a decrease in the likelihood of observing the red-light violation. The results of comparing the proposed RLR estimation method with several conventional methods, the Poisson Generalized Linear Model (PGLM), Zero-inflated Poisson Regression Model (ZIPM), and Zero-inflated Negative Binomial Regression Model (ZINB) showed the proposed method outperforms all the models in terms of both model fit and accuracy. The application of the proposed method could be used to analyze the intersections with the highest number of red-light violations. Furthermore, the presented transferability results can be advantageous to transportation agencies within Arizona and urban areas with similar characteristics by providing insight into which model specifications may provide the best RLR estimation accuracy.

Splitting failure and deformation evolution of the red argillaceous siltstone disc in the high humidity environment

The failure mechanism of weakly cemented soft rock under water-rock coupling effect is extremely complex. To reveal the tensile failure of red argillaceous siltstone in high humidity environment, five kinds of disc samples with different water contents were obtained through maintenance in constant temperature and humidity oven. The Brazilian test was carried out to reveal the variation characteristics of splitting behavior of rock samples in high humidity environment. Detailed analysis was conducted on the evolution law of stress-strain relationship and mechanical parameters under five different water contents. Combined with the DIC (Digital Image Correlation) investigation, the displacement evolution patterns of samples with different water content and loading stages were analyzed. Results show that he macroscopic mechanical parameters such as tensile strength and elastic modulus of weakly cemented red sandstone samples under water environment are negatively parabolic correlated with the increase of water content. The moisture content has an important influence on the disc splitting failure mode, forming the main fracture along the radial direction of loading, and showing a local crushing area in the loading area, and the crushing area increases with the increase of water content. Microstructural variation of red sandstone under a high humidity environment is the main reason for its deterioration of macroscopic mechanical properties.

Mechanical properties of modified coral aggregate seawater sea-sand concrete: Experimental study and constitutive model

The use of corals, seawater, and sea-sand to prepare concrete can effectively solve the problem of raw material transportation in constructing remote sea islands and reefs. Corals have the disadvantages of high porosity, high water absorption, and low crushing strength, which adversely affect the performance of concrete. In this study, corals were modified by a superfine cement paste, and the modified coral aggregate seawater sea-sand concrete was prepared by replacing gravel aggregates proportionally with modified coral aggregates. The cubic compressive, splitting tensile, flexural, and axial compressive properties of modified coral aggregate seawater sea-sand concrete with five aggregate replacement ratios were studied. The results showed that the coral aggregate was divided into two parts after the concrete failed. The higher the replacement ratio of the aggregates, the smoother the splitting failure surface of the concrete. The modification measures could not significantly improve the compressive and tensile strengths of coral aggregate concrete, and the increasing rate was less than 10%. The compressive strength of concrete using modified coral aggregates was approximately 30% lower than that of concrete using gravel. Based on the experimental results, a prediction model, which can simulate the compressive stress-strain relationship of coral aggregate concrete under different replacement ratios, was proposed.

Experimental investigation on the bond-slip behavior between TRC-confined concrete and rebars after exposure to elevated temperatures

In this study, the bond-slip behavior between textile reinforced concrete (TRC)-confined concrete and rebars both at ambient temperature and after ISO 834 standard fire was investigated experimentally through pull-out tests. The failure modes, ultimate load, average ultimate bonding stress and energy consumption were obtained and discussed. Effects of rebar diameters (12 mm, 14 mm and 16 mm), bonding lengths (2.5d, 5d and 7.5d) and high-temperature exposure durations (30 min and 60 min) on the bonding behavior between TRC-confined concrete and rebars were examined emphatically. It was observed that the damage modes of specimens changed from pull-out failure at ambient temperature into splitting failure for both TRC-confined specimens and companion unconfined specimens exposed to high temperatures. The results obtained demonstrated that both the ultimate load and the average ultimate bonding stress can be significantly improved by the utilization of TRC jackets after 30 min exposure, and the increment of the average ultimate bonding stress can reach up to 90% as compared to those unconfined specimens. However, the enhancement of TRC jackets became unobvious after 60 min. Finally, based on test results and Prigogine’s dissipative structure theory, the energy analysis of bond-slip curves was evaluated to verify the enhancement of TRC jackets quantitatively.

Enhancing the mechanical and energy release performance of nano-aluminum@fluororubber (nAl@F2311) core–shell microstructured composite materials

Aluminum (Al)-based reactive materials have recently attracted much attention due to their excellent chemical energy release characteristics. However, there still exists a great challenge to improve the mechanical properties and energy density of Al-based reactive materials. In this work, we reported that core–shell nano-aluminum@fluororubber (nAl@F2311) composites with good mechanical properties and high energy release characteristics were designed and fabricated by the electrical exploding wires method. The results showed that Al nanospheres were coated by F2311 uniformly to form the nAl@F2311 core–shell microstructure with high Al contents. Quasi-static/Split Hopkinson Pressure Bar dynamic compression test results showed axial splitting failure mode of nAl@F2311 composites. nAl@F2311-10 composites with 90 wt. % Al contents had higher compressive strength, with quasi-static and dynamic compressive strength of 117.6 and 304.6 MPa, respectively. nAl@F2311-15 composites with 85 wt. % Al contents had a lower ignition threshold. Furthermore, the impact-induced energy release test showed higher fluorine contents will accelerate energy release, reduce impact ignition threshold, and improve the reaction efficiency of nAl@F2311 composites. The high reaction efficiency (97.79%) of the nAl@F2311-15 composites was obtained at an impact velocity of 1090 m/s. This offered a concept-of-proof work to design and fabrication of nanostructured reaction materials, which had high strength and energy release performance.

Bond performance and physically explicable mathematical model of helically wound GFRP bar embedded in UHPC

Due to the superior corrosion resistance, glass fiber reinforced polymer (GFRP) reinforced ultra-high performance concrete (UHPC) structure has been regarded as an attractive alternative to traditional RC structure exposed to harsh environments. In this work, upon the pull-out tests of 54 specimens, the bond behaviors between helically wound GFRP bar and UHPC were investigated, with an emphasis on the evaluation of the effects of GFRP bar diameter, embedment length, concrete cover thickness, and fiber characteristic parameters (i.e., volume fraction and aspect ratio) of steel-polypropylene hybrid fiber. The bond failure mode, ultimate bond strength, and bond stress-slip curve were analyzed. The results showed that the bond damage at GFRP-UHPC interface mostly occurred on the GFRP bar surface due to the relatively lower strength of GFRP ribs. The bond strength presents an upward trend with an increase in the thickness of concrete cover and volume fraction of steel fiber, whereas it decreases with the increase of GFRP bar diameter and embedment length. Moreover, the fibers in the UHPC matrix exerted a significant impact on the bond behaviors that could alter the bond failure mode from the concrete splitting failure to the pull-out failure. Finally, based on the experimental observations, a new physically explicable mathematical bond stress-slip model was proposed to reproduce the main features of the whole debonding process. The satisfactory predictions against the test results from independent research demonstrated that the proposed three-phase analytical model represents a compromise between accuracy and generality, providing a beneficial reference to the design of the GFRP reinforced UHPC structure.

Experimental investigations of bond behavior of double-row spliced rebars in Ultra-High Performance Concrete (UHPC)

The paper aims to evaluate the bond behavior of spliced rebars in Ultra-High Performance Concrete (UHPC). A total of 27 double-row spliced specimens were prepared and tested under direct tension where the test variables covered bar diameter (14 mm and 25 mm) and splice length (2db, 4db, 6db and 8db). The failure mode, crack pattern, bond-slip relationship, bond strength, and bond stress distribution were determined and discussed. Three failure modes including rebar pullout, rebar rupture and UHPC splitting were observed. Owing to the bridge action of steel fibre in the post-cracking phase, the splitting failure was ductile. The bond strength decreased as the splice length and bar diameter increased. For db of 14 mm, the bond strength of specimens with splice lengths of 4db, 6db and 8db dropped by 30.9 %, 40.6 % and 50.1 % than that with a splice length of 2db, respectively. Under various splice lengths, the bond stress presented uniform distribution, single peak distribution and bimodal distribution profiles. Moreover, the design recommendation for the critical splice length of rebars in UHPC was presented and compared with the current specifications.

Do existing split failure metrics accurately reflect pedestrian operation at signalized intersections?

Automated Traffic Signal Performance Measures (ATSPMs) uses high-resolution data to develop operational performance measures for signalized intersections. Split Failure (SFs) is one of the primary metrics to identify intersections with operational issues. These SFs are determined by measuring vehicle occupancy for a given movement during its green time (i.e., Green Occupancy Ratio or GOR) and immediately after the signal turns red (i.e., Red Occupancy Ratio or ROR5). While the SF metric is a great tool for signal operations and rebalancing green times, it focuses entirely on vehicular measures and ignores the treatment of pedestrians at the intersection. Prioritizing vehicular movements may lead to excess pedestrian delay, which may cause pedestrians to violate traffic signals.To address this issue, this paper examines the relationship between pedestrian delay and GOR or ROR5. The main objective was to identify whether the GOR and ROR5 could be adequately used as a proxy for pedestrian delays. To achieve this goal, high-resolution data was collected from the ATSPMs database at a signalized intersection in Salt Lake City, Utah. To predict GOR or ROR5 as a function of pedestrian delay, a linear regression model was developed. The results reveal that there is very weak to no relationship between these metrics. This implies that using only GOR or ROR5 in quantifying signal performance does not meaningfully capture pedestrian delay and thus might overemphasize vehicle movements. Specific pedestrian delay metrics should be included in a signal operation analysis to identify operational issues.

Fracturing evolution and strain characteristics of layered rock-like materials with rough interfaces

Layered rock-like samples containing saw-tooth interfaces of various joint roughness coefficients (JRC) and included angles were conducted uniaxial compression with the loading rate of 0.005 mm/s. The peak stress declines from 38.36–39.90 MPa to 17.35–30.67 MPa for included angle = 15°–60°, and then increases to 24.30–33.83 MPa for 60°–75°, but the peak strain decreases by 22.39%–41.30%. For JRC = 0–19.55, mechanical properties of samples are enhanced, while the anisotropy weakens. When the included angle is small (15°, 30°), the layered samples show a typical tensile splitting failure crossing the weak interlayers. For a large included angle of 45°–75°, failure modes are featured by shear sliding along weak interlayers combined with tensile splitting. As JRC increases, fracturing mechanism transition from shear sliding to mixed tension shear failure then to tensile splitting can be identified. With an increase in JRC or included angles, the global lateral strain of samples in plastic deformation stages changes from “sudden increase” to “progressive increase” to “jump increase”. For included angle = 15°, the layered sample produces dramatic lateral local strain at the weak interlayers due to tensile splitting failure. For included angle = 45°, both axial and lateral local strains at the weak interlayers show an obvious increase at the main shear failure surface. For a large included angle of 75°, the lateral local strain remarkably increases at the weak interlayers along with tensile failure of samples.

Cracking behaviour of textile-reinforced concrete with varying concrete cover and textile surface finish

The cracking behaviour of textile-reinforced concrete (TRC) impacts the serviceability and structural integrity of TRC beams. However, textile reinforcement has not yet been standardised and there are numerous available textile reinforcement options. In spite of evidence that the textile properties influence the cracking behaviour of TRC, knowledge of the role of the textile, concrete and geometric parameters on cracking is still limited. This paper investigates a commonly used subset of textile reinforcements, namely epoxy-impregnated textiles with a high yarn count, some of which are prone to induce splitting failure. Through a comprehensive experimental study of 144 uniaxial reinforced concrete tensile tests, the influence of the textile fibre strand geometry and surface finish (plain or sand-coated) on the cracking behaviour was investigated in dependency of the concrete cover thickness. The results show that sand-coating treatment can decrease the transverse crack width to one-third of those observed in analogous plain textile specimens. The geometry of the plain fibre strands, which is affected by the textile fabrication method, also leads to significant differences in the measured crack widths (factor of 2.5). The overall cracking behaviour, however, is decisively influenced by the occurrence of splitting (longitudinal) cracks in the layer of the textile reinforcement, which were observed regardless of the surface treatment for concrete covers thicker than 15 mm. In case of the sand-coated textiles, these splitting cracks initiated immediately after the first main crack and propagated throughout the specimen, which diminished any tension stiffening effect. In the plain textile samples, the cracks led to an excessive spalling of the concrete cover. The results of this study provide a deeper understanding of the cracking behaviour of TRC with epoxy-impregnated textiles and a comprehensive database for further research. This establishes the basis for unified regulations regarding the limit states of TRC structures.

The combined effect of temperature and seawater on the compression properties of carbon fiber vinyl ester composites for sandwich structures

For naval applications, composite sandwich structures are of significant interest, and are often manufactured using thin (2 to 4 mm) composite facings made from carbon or glass fiber reinforcement, attached to a thick (25 to 50 mm) section of PVC cellular foam or balsa wood-based core materials using a suitable polymeric resin. In the present study, we focus on the hygrothermal effect on the fiber-dominated compression properties of carbon fiber reinforced vinyl ester resin based polymeric composite (CF/VE), used as “skin” for a polymeric composite sandwich material. Hygrothermal conditioning is achieved by saturating samples in simulated seawater at 40°C. Compression properties are evaluated for coupons extracted along warp and fill undergoing- no conditioning, conditioning till saturation (up to 6 months), and long-term conditioning (2 years). Sea-water saturation yields in up to 12% drop in compression strength with a further 3–4% drop resulting from long-term conditioning. No statistically significant modulus degradation is noticed due to short or long-term hygrothermal exposure. The failure mechanism of the warp extracted coupon, which fails in a splitting failure mode originating due to the delamination between the 0/90 interface, or the fill extracted coupon, which fails due to the instability caused by tow micro-buckling, remains unchanged due to combined exposure (short or long-term) of seawater and temperature. The loss in strength is attributed to the degradation of the fiber-matrix interface, which is validated via conducting single fiber push-in tests with a nominal diameter of 7 micron for conditioned and unconditioned coupons.

Prediction of Failure Modes and Minimum Characteristic Value of Transverse Reinforcement of RC Beams Based on Interpretable Machine Learning

Shear failure of reinforced concrete (RC) beams is a form of brittle failure and has always been a concern. This study adopted the interpretable machine-learning technique to predict failure modes and identify the boundary value between different failure modes to avoid diagonal splitting failure. An experimental database consisting of 295 RC beams with or without transverse reinforcements was established. Two features were constructed to reflect the design characteristics of RC beams, namely, the shear–span ratio and the characteristic value of transverse reinforcement. The characteristic value of transverse reinforcement has two forms: (i) λsv,ft=ρstpfsv/ft, from the China design code of GB 50010-2010; and (ii) λsv,fc′=ρstpfsv/fc′0.5, from the America design code of ACI 318-19 and Canada design code of CSA A23.3-14. Six machine-learning models were developed to predict failure modes, and gradient boosting decision tree and extreme gradient boosting are recommended after comparing the prediction performance. Then, shapley additive explanations (SHAP) indicates that the characteristic value of transverse reinforcement has the most significant effect on failure mode, follow by the shear–span ratio. The characteristic value of transverse reinforcement is selected as the form of boundary value. On this basis, an accumulated local effects (ALE) plot describes how this feature affects model prediction and gives the boundary value through numerical simulation, that is, the minimum characteristic value of transverse reinforcement. Compared with the three codes, the suggested value for λsv,fc′,min has higher reliability and security for avoiding diagonal splitting failure. Accordingly, the research approach in this case is feasible and effective, and can be recommended to solve similar tasks.

Degradation of the bond performance between composite limestone powder concrete and steel bars under a sulfate freeze–thaw environment

An experimental investigation was conducted to explore the degradation of the bond performance between five types of composite limestone powder concretes and steel bars under a sulfate freeze–thaw environment. The failure model, ultimate bond strength, peak slip and bond–slip curve were researched. Three types of anchorage lengths were adopted in the investigation. The results indicated that limestone powder and fly ash reduced the ultimate bond strength and increased the peak slip of split failure. Slag increased the ultimate bond strength and reduced the peak slip. The bond performance between the composite limestone powder concrete and steel bars decreased with increasing anchorage length. Limestone powder exacerbated the degradation of the bonding performance of concrete under freeze–thaw cycles, while slag slowed the reduction in ultimate bond strength and corresponded with lower peak slip and more brittle failure. The constitutive relationship between the conventional environment τ (s, d/L) and the sulfate freeze–thaw environment τ (s, fts) was established, and the correction factor for the critical anchorage length of the sulfate freeze–thaw environment was derived. Thus, the influences of limestone powder, fly ash and slag on the critical anchorage lengths were analysed.