Shear Capacity Of Joints Research Articles

FAULTING PERFORMANCE MODEL FOR UNDOWELED JOINTED CONCRETE PAVEMENTS USING SHRP-LTPP DATABASE

Joint faulting of undoweled transverse joints contributes to longitudinal roughness, and subsequent user discomfort (poor ride quality) and needs for rehabilitation and repair. In this paper the authors propose two (based on support conditions) joint faulting prediction models based on the Strategic Highway Research Program (SHRP) - Long Term Pavement Performance (LTPP) database. The models consist of explanatory variables like shear capacity, pavement support, temperature, unconfined compressive strength, size ratios, and pavement response. Variables (from the database) like shear capacity, load transfer efficiency, pavement support, and crack widths were back calculated using mechanistic-empirical algorithms for more realistic estimates. Efforts were made to determine the form of the model and explanatory variables that made engineering sense, rather than blindly relying on statistical tools. The paper discusses the methodology used in selecting explanatory variables (independent variables) in the model development and results of the sensitivity analysis. The analysis of the data has shown that undoweledjoint faulting is a function of traffic, joint shear capacity, joint spacing, base type and pavement support. The paper provides a comprehensive reliability analysis (with illustrative example) of the models developed.

Shear mechanism and bearing capacity calculation of steel fiber reinforced concrete beam-column joints

Based on the strut-and-tie model, the shear mechanism of steel fiber reinforced concrete (SFRC) beam-column joints is analyzed. In addition, based on the stress characteristics of SFRC beam-column joints, the influence of randomly distributed steel fibers at the cracks is equated to the effective bond stress of the steel fibers. Consequently, a formula for calculating the shear capacity of SFRC beam-column joints is proposed. Furthermore, a database of 132 SFRC beam-column joints is compiled. Based on the database, the proposed calculation method is optimized using statistical analysis method. Furthermore, the contributions of concrete, stirrups, and steel fibers to the shear bearing capacity are discussed. Finally, the proposed calculation method is compared with the existing calculation methods to validate the accuracy of the model. The results indicate that the shear bearing capacity provided by concrete can reach 90% of the total shear bearing capacity. The maximum shear bearing capacity provided by stirrups and steel fibers is 27% and 26% of the total shear bearing capacity respectively. When the stirrup ratio exceeds 1%, the enhancement of shear bearing capacity by the stirrups becomes more pronounced. Compared to straight steel fibers, hooked-end steel fibers can better enhance shear capacity. The proposed calculation method demonstrates higher accuracy compared to existing calculation methods, which can be used to predict the shear bearing capacity of SFRC beam-column joints.

Effect of high-strength SCC with and without steel fibres on the shear behaviour of dry joints in PCSBs

The structural behaviour of precast concrete segmental bridges (PCSBs) heavily relies on the strength of the joints between segments. Multi-keyed dry joints are currently the most commonly used solution in these discontinuity zones. Employing high-strength concrete is becoming increasingly common in civil engineering given its higher strength and improved durability. It specifically allows higher prestressing levels in PCSBs. Using self-compacting concrete enhances workability and adding steel fibres improves mechanical properties. The existing scientific literature includes experimental tests to analyse the shear behaviour of castellated dry joints in different concrete types. However, no experimental tests appear specifically for the castellated dry joints made with high-strength self-compacting concrete (HS-SCC) with and without steel fibres. Therefore, this experimental study conducted 31 push-off-type tests to analyse the behaviour and shear capacity of dry joints made of HS-SCC by investigating the influence of adding steel fibres to the concrete mix. The study examined crack patterns, load-displacement behaviour, failure modes and different (cracking, ultimate and residual) loads. The addition of steel fibres improved joints’ shear capacity. However, brittle behaviour was observed after reaching ultimate load when using HS-SCC, even when steel fibres were added to the concrete mix. Finally, the adequacy of existing formulations was analysed. Standard AASHTO proved to be on the unsafe side for the castellated dry joints specimens made of HS-SCC without steel fibres, and provided a good approximation for the specimens with steel fibres.

Prediction of Strength and Failure Modes in Reinforced Concrete Beam–Column Joints using Ensemble Machine Learning Techniques

The beam-column joint is one of the important structural elements that control the structural behaviour during seismic excitation. Moreover, failure of any of these components may lead to the partial or overall collapse of the entire structure. In view of the safety concern, there is a need to evaluate the response properties, such as failure modes and ultimate shear capacity of the beam-column joints. Conventional methods to evaluate the shear capacity of beam-column joints are usually time-consuming. Therefore, in this study, an attempt has been made to evaluate the joint shear capacity and mode of failure of an exterior beam-column joint using ensembled machine learning (ML) approaches like Decision Tree, Random Forest, AdaBoost, CatBoost, and LightGBM. The present study highlights the potential use of the CatBoost model as a useful tool that can assist in predicting the shear strength and failure mode. The results of the study reveal that this model has performed well in predicting the load-carrying capacity and shear strength with high correlation coefficients of 0.9836 and 0.9978, respectively. Moreover, it has been observed that the prediction model provided by the CatBoost algorithm exhibits the highest accuracy for classification in the failure mode of beam-column joints.

Data-driven study on shear bearing capacity of segmental concrete joints

Segmental assembly joints with excellent shear bearing capacity are the key to ensure the integrity of precast concrete girder bridges, which directly affects the force transmission state of the girders. However, with the existence of unfavorable factors such as the multi-key shear capacity reduction effect, the traditional prediction model for calculating the concrete joints shear capacity has poor prediction accuracy and large dispersion. To overcome the shortcomings of the existing prediction model, this study established a database consisting of 311 sets of test data and 110 sets of numerical results based on existing research. A total of seven data-driven models for predicting shear capacity of concrete joints were trained and generated based on the database, namely, two linear models (Linear Regression Support Vector Machine Algorithm, Least Squares Linear Regression) and five nonlinear models (Neural Network Bayesian Regularization; Neural Network Quantized Conjugate Gradient Model, Neural Network Levenberg-Marquardt (LM), Decision Tree, and Gaussian regression). The coefficient of determination (R2), root mean square error (RMSE)，mean absolute error (MAE), error range (A20-index), and error analysis were adopted to evaluate those model's performance. The evaluation results show that the LM model has excellent prediction accuracy, stability, robustness, and can guide the engineering design. Finally, the established database (421 data sets) and trained LM algorithm model were open sourse in this study to promot the investigate of precast concrete structures.

Examination of the beam eccentricity on shear capacity of RC eccentric beam-column joints

The layout of the exterior retaining walls and external thermal insulation demands often introduce an eccentricity between the central axes of the beams and columns, leading to what is termed as an eccentric beam-column joint. Such the beam eccentricity is a key factor in shear failures within the joint region. This study addresses the negative impact of beam eccentricity on the shear capacity of reinforced concrete (RC) eccentric beam-column joints. Current research indicates that in the five prevailing shear capacity formulas of RC eccentric joints, adverse effects are primarily accommodated by either reducing the joint’s effective width ( bj) or implementing an eccentricity influence factor. The study challenges the validity of these approaches by dissecting the impact of singular and interactive factors, including. Eccentricity (2 e/ bc), beam-to-column width ratio ( bb/ bc), and the column’s aspect ratio ( hc/ bc). It was observed that while the influence of 2 e/ bc is generally well-accounted for, the effects of bb/ bc and hc/ bc are not adequately considered in the Chinese code and ACI-318. Leveraging the softened strut-and-tie model and insights from these examinations, a refined formula for determining the shear capacity of eccentric joints is introduced. This formula incorporates the detrimental effects of beam eccentricity through a newly conceptualized eccentric influence factor, which is a function of both 2 e/ bc and bb/ bc. Compared to existing models, this proposed formula also factors in the beam-to-column depth ratio and the longitudinal reinforcement in the middle of column section. Validation against experimental data from 26 eccentric joints demonstrates that the proposed formula yields predictions with the closest proximity to actual test results and the least variability compared to the five established formulas. This approach to considering the effects of e/ bc and bb/ bc proves to be slightly more accurate than Zhou’s model, making it a promising alternative for practical applications.

The direct shear behavior of the ultra-high performance concrete-filled socket connections between the bridge piers and footings

Ultra-high performance concrete (UHPC)-filled socket connections (UFSCs) provide a novel method for connecting bridge piers and footings, and allow for high matching tolerance and accelerated construction. At present, the lack of related research on the direct shear behavior of UFSCs hindered the promotion of this technology. This paper carried out the push-out test to explore the influences of embedded depths, horizontal confining pressures, and the shear key shapes on the direct shear behavior of the UFSCs. Monolithic specimens were also tested as a reference. The experimental results showed that increasing the socket depth and horizontal confining pressure has a positive impact on the direct shear capacity. With the same key width, escalating the key root height could also enhance the direct shear capacity. The experimental results also indicated that the load-bearing capacity of UHPC-connected specimens was generally lower than those of corresponding monolithic specimens. AASHTO and JSCE formulas were used to predict the direct shear capacity of joints, which relatively underestimated the experimental results. The average ratio between the calculated values of the two formulas and experimental results was 0.70 and 0.81, respectively. Based on the strut-and-tie model (STM), the shear capacity formula for UFSC was proposed, exhibiting a high degree of agreement with the test results, with an average ratio between calculated values and experimental results of 0.98.

Interpretable ensemble machine learning models for predicting the shear capacity of UHPC joints

Precast ultra-high-performance concrete (UHPC) structures (PUSs) have gained increasing research and application interest in civil engineering owing to the combination of advanced construction materials and methods. UHPC joints are critical parts of PUSs; thus, an accurate prediction of their shear capacity (SC) is essential to ensure structural safety and reliability. However, existing equations for predicting SC have limited accuracy and applicability owing to their simplified assumptions and restricted input parameters. To address these challenges, this study used machine learning (ML) approaches to develop a unified and accurate predictive model for various types of UHPC joints. A well-curated database containing 218 UHPC joints with diverse types and configurations was established. Six ensemble algorithms and four traditional algorithms were employed to develop predictive models, and eight existing equations were compared for performance evaluation. Both correlation-based and SHAP-based feature selection methods were used to optimize the model accuracy. The ensemble algorithms demonstrated better performance than the traditional individual algorithms, with the gradient boosting machine (GBM) model ranked as the best ML model for SC. The ML model outperformed existing equations in all evaluated metrics, demonstrating its accuracy and robustness. Furthermore, Shapley Additive exPlanations (SHAP) analysis was employed to interpret the ML model, thereby providing insights into influential features and their relationships. These findings demonstrate the advantages of ML methods in predicting the SC of UHPC joints and provide valuable guidance for the structural design and research on PUSs.

Application of Organo-Modified Silica Nanoparticles to Improve the Load-Bearing Capacity of Bonded Joints of Dissimilar Steel Substrates

The paper deals with the joining of dissimilar steels by adhesive bonding. The base materials for the experimental work were deep-drawn low-carbon steel DC04, and hot-dip galvanized HSLA steel HX340LAD+Z. Adhesive bonding was performed using rubber-based and epoxy-based adhesives. The research aimed to verify the importance of surface preparation of steel substrates using a formulation with organically modified silica nanoparticles and epoxy organic functional groups, where one end of the functional group can be incorporated into the organic binder of the coating material and the other end can be firmly bonded to substances of an inorganic nature (metals). Since the binder base of adhesives is very similar to that of coatings, verifying the performance of this surface preparation when interacting with the adhesive is necessary. The load-bearing tensile shear capacity of single-lapped joints and the resistance of the joints against corrosion-induced disbanding in a climate chamber were tested. The energy dissipated by the joints up to fracture was calculated from the load-displacement curves. Bonded joints with organosilane were compared with joints without surface preparation and joints prepared by chroman-free zirconate passivation treatment. Exposure of the joints in the climatic chamber did not cause a relevant reduction in the characteristics of the joints. Organosilicate formulation was proved effective when bonding ungalvanized steels with a rubber-based structural adhesive, where it improves the bond quality between the adhesive and the substrate.

Analysis of the Mechanical Behavior and Joint Shear Capacity Optimization of Glued Keys in Segmental U-Shaped Bridges

This paper presents an in-depth analysis of the mechanical behavior and joint shear capacity optimization of segmental U-shaped bridges, with a focus on the application of precast segmental techniques in the construction of U-beam bridges widely used in urban rail transit networks. This study further explores the roles of key position distribution and size in the overall stability and service behavior of such structures. Considering the critical case study of the Colombia Bogotá Metro Line 1 project, finite element modeling was carried out using ABAQUS 6.14 to simulate concrete material behaviors and to evaluate the stress–strain relationship in accordance with the concrete plastic damage model and existing standards. This research identifies the significant contribution of keys in minimizing deformation and enhancing shear capacity, demonstrating the pivotal influence of shear key design on the mechanical behavior of segmental bridges. By calculating the shear capacity under different cases, this study provides recommendations on key distributions and dimensions that optimize joint shear capacities, indicating that augmenting key size within the web plate section decisively reinforces the bridge’s mechanical resilience.

Experimental and analytical studies on direct shear performance of UHPC keyed joints

The keyed joint in the precast ultra-high-performance concrete (UHPC) segmental bridge (PUSB) plays a critical part in the structural behavior of the entire bridge, which requires in-depth investigations to clarify its shear performance. To this end, experimental and analytical studies on 15 UHPC keyed joints were conducted to explore the effects of the joint type, number of teeth, size of teeth, angle of teeth, and reinforcement method on the shear behavior of UHPC keyed joints. Test results presented that the failure modes were significantly affected by the teeth number and the reinforcement method, which can be classified into three primary categories (direct shear, segmental shear, and stepwise shear). The epoxied joints exhibited better shear capacity and ductility than those of dry joints, and the large-keyed joints owned higher shear capacity than the small-keyed joints under the same shear area. Moreover, the mechanisms of the two reinforcement methods were analyzed: the teeth rebars effectively improved the brittleness of the specimen, and the internal tendons significantly enhanced the shear efficiency of the specimen. Finally, considering the bridging effect of steel fiber, a calculation model was proposed for the shear capacity of the UHPC epoxied-keyed joints. The test results were in good agreement with the analysis results, indicating that the proposed model can be used to predict the shear capacity of UHPC epoxied-keyed joints.

Static behavior of stiffened CFST KK joints of offshore wind turbines under antisymmetric loading

This study examines the static behavior of the critical joints of the new kind of offshore jacket foundations under antisymmetric loading by employing a combination of experiments, finite element analysis (FEA), and theoretical derivation. Three tests and 35 FEAs of stiffened concrete-filled steel tubular (CFST) KK joints are described. The introduction of a novel perfobond ring rib (PRB) as a stiffener, along with using a limiting fixture during loading to consider interactions among the four braces, are novelties of this research. Experiments compare the influence of stiffener rib forms (PRB and Perfobond Leister Ribs (PBL)) on the behavior of CFST KK joints, highlighting the superiority of PRB strengthening. However, the influence of the stiffener rib form on the stiffness of the CFST KK joints can be ignored. The properties of PRB-stiffened CFST KK joints are further investigated via validated FEA models, which introduce the modified Mohr-Coulomb (MMC) criterion to realize steel fracture damage. A parametric analysis is then undertaken to explore how variations in the joint's geometrical parameters, chord material strength, and thickness and quantity of the PRBs influence the punching shear capacity of PRB-stiffened CFST KK joints. Furthermore, a formula is presented for punching shear strength in PRB-stiffened CFST KK joints by employing the superposition method. Its predictions align well with both experimental and FEA results.

Shear behaviour and theoretical model of large shear key dry joints in precast concrete segmental bridges using advanced monitoring

Keyed dry joints are commonly utilised in segmental bridges for shear stress transmission. The aim of this study is to explore the shear behaviour and capacity of large shear key dry joints. The considered parameters included key base height, key number and concrete strength. The key base heights were found to have a significant impact on the failure mode and shear carrying capacity. When the key base height is increased by 100%, the shear carrying capacity of the joint is increased by 156%. Digital image correlation (DIC) and distributed fibre optic sensing (DFOS) technologies revealed the characteristics of load transfer in the large shear key, validated the principle of inclined strut column and observed the changing angle of inclined column with the increase in shear key size. Moreover, due to the shear transfer at the large key teeth, there is a trend of separation in the lower contact surfaces of the joint. Based on these findings, an improved calculation method for the shear strength of large key dry joints was established. The calculation results show more accurate predictions for large key dry joints than available calculation methods developed for smaller keyed dry joints.

Anchorage characteristics and their impacts on the seismic performance of HECC/RC composites external beam-column joint

In order to enhance the seismic performance and streamline the construction process, particularly in precast frame structures, steel-polyethylene hybrid fiber-reinforced engineered cementitious composites (HECC) is utilized to replace reinforced concrete (RC) in the external beam-column joint core area to form HECC/RC composite joints. In this study, to further alleviate rebar congestion, five no-stirrup reinforced HECC/RC composite external beam-column joints with reduced beam longitudinal rebar anchorage length (i.e., 6d-18d) in core area and one control RC specimen are designed and tested under cyclic loading. Experimental results indicate that anchorage failure occurs until the anchorage of the beam longitudinal rebar decreases to an extremely short length of 6d. In comparison with the control RC specimen, HECC/RC specimens display a reduced bond damage zone and superior bond behavior. Although relatively larger stress is transferred to the anchorage free end when anchorage length is 9d, the beam longitudinal rebar is still effectively anchored without significant slip, indicating that anchorage length of 9d in joint core area may be sufficient which needs further research. In addition, the ultimate bond strength of the rebar embedded in joint core area is lower than that observed in pullout test, underscoring the necessary of considering a safety factor in design anchorage length estimation. Lastly, the contribution of bonding condition on shear force transfer in joint core area is analyzed according to force transfer mechanism, which would promote the determination of the shear capacity of HECC joint. As the bonding damage expanded, the proportion of shear force resisted by truss mechanism decreases, emphasizing the crucial role of adequate anchoring in external joint.

Numerical simulation and design method of dowel-type timber joints connecting laminated veneer lumber

Dowel laminated timber (DLT) is a structural engineering wood product composed of laminates connected by wood dowels. It has the characteristics of green, low-carbon, and a high degree of prefabrication. Wood dowel connection is the forming method of DLT, and its joint design is the key to DLT. The properties of laminates affect the mechanical properties of both DLT and dowel-type timber joints. Laminated Veneer Lumber (LVL) is an engineering wood product made by gluing veneers along a fixed grain direction, with excellent physical and mechanical properties. Utilizing small-thickness LVL as the laminates of DLT, a design method of dowel-type timber joints connecting LVL was explored through numerical simulation and theoretical calculation. A three-dimensional finite element model of dowel-type timber joints connecting LVL was presented, and experimental calibration were carried out. The parametric study was adopted to explore the influence of main variables on the shear performance of joints. The calculation formula for the shear capacity of joints was proposed and optimized, and the design method of joints was summarized. The results indicated that the failure mode and shear capacity of joints were dramatically influenced by two variables: the ratio of side laminate thickness to dowel diameter (n) and the thickness ratio of middle-to-side laminate (m). The two variables affected the shear capacity of joints by affecting the failure mode of joints. When the ratio of side laminate thickness to dowel diameter was 1 < n ≤ 3.75, the optimized Johansen theoretical formula could effectively predict the shear capacity of dowel-type timber joints connecting LVL.

Assessment of the impact of column-to-beam strength ratio on seismic response of RC beam-column connections

Beam-column joints play an important role in the overall resistance of reinforced concrete frames during seismic events. The Earthquakes of Al Asnam on October 10, 1980, and Boumerdes on May 21, 2003 in Algeria, have highlighted the failure of beam-column joints as a cause of building collapse. 3D nonlinear finite element analysis with ANSYS software has been used in order to examine exterior RC beam-column joints under monotonic loading. The research has investigated the influence of the value of the column-to-beam strength ratio (CBSR) of these joints on shear strength and seismic performance of concrete structures by changing the height and longitudinal reinforcement of the beam while keeping column dimensions constant. It has been shown that the beam-column depth ratio and the beam longitudinal reinforcement ratio have a significant effect on the shear capacity and seismic behaviour of exterior beam-column joints. An appropriate value of the flexural strength ratio between the column and beam is crucial in order to establish a "strong column-weak beam" mechanism in reinforced concrete frames, because inadequate values can lead to premature failure or reduced shear capacity at the junction. The Algerian seismic code – RPA99/version2003 suggests a minimum value of column-to-beam strength ratio equal to 1.25 at joints for seismic design when building codes in other countries call for higher ratios. Nevertheless, this approach might not accurately represent the actual behaviour and could constrain the optimal performance of structures.

Static performance of multi-planar CFST chord-CHS brace KK joints

This paper investigates the static performance of jacket joints to promote the application of CFST jacket foundations for offshore wind power. An experimental and numerical study of the influence of loading patterns, concrete filling in the chord, geometric parameters, and material strength is examined. In total, five 1:6 scale tests and twenty-eight FEAs are described. The novelty is that a limit device is introduced to consider the interaction among the braces by connecting four braces. The experimental results indicate that, compared to symmetrical loading joints, the bearing capacity of CHS-KK joints decreased by 14% under anti-symmetric loading. Concrete filling in the chord alters the failure mode, enhancing the ultimate bearing capacity of the KK joint. However, its effect on the punching shear failure strength of the joint is limited. An FEA model incorporating the modified Mohr-Coulomb criterion (MMC) was established to explore the ultimate strength of CFST-KK joints, following validation through experiments. Through parameter analysis, it was found that the punching shear capacity of CFST-KK joints is significantly influenced by the diameter ratio of the brace to chord (β), the chord diameter to thickness ratio (2γ), the angle between the brace and chord axis (θ), and the chord steel strength. In addition, the recommended formula in GB50017–2017 for CHS-KK joint punching shear capacity conservatively predicted CFST-KK joint performance.

Experimental and finite element analysis on mechanical performance of prefabricated assembly inverted arch to lining joints of large section highway tunnel under direct shear loding

To investigate the mechanical properties of the prefabricated inverted arch to cast-in-place lining joints, 21 "Z"-shaped shear specimens for direct shear testing were designed and manufactured, with the interface planted steel bars ratio, interface size, and interface treatment method as variable parameters. The whole failure process of the joint under a direct shear stress state was observed and recorded during the test, the shear-slip curve of the specimen was obtained, failure mechanism and variation law of the joint's direct shear mechanical characteristics were carefully examined. The results reveal that the specimen's shear performance improves following the interface chiselling treatment. The specimens fail in three ways: simple concrete failure, simple planted steel bars failure, and assimilative failure of the concrete and the planted steel bars. The ultimate shear capacity, ductile failure capacity, resistance to damage evolution, and energy dissipation capacity of the specimens rise as the planted steel bars ratio increases. When the planted steel bars ratio increases from 0.7% to 1.1%, the improvement is the most significant, reaching 66.3%. When the planted steel bars ratio is the same, the shear bearing capacity improves as the interface size grows. The finite element model of the “Z”-shaped shear specimen of the prefabricated inverted arch and the cast-in-place lining joint is established, and the parameter extension analysis is performed. Based on the test results and the Extended Shear-Friction Theory, a high-accuracy calculation model of shear capacity of precast inverted arch and lining joint is presented.

Experimental and Numerical Investigation of the Shear Performance of an Innovative Keyway Joint for Prefabricated Concrete Wall Panels

To improve the shear performance and construction efficiency of horizontal joints in prefabricated concrete wall panel structures, an innovative keyway joint for prefabricated concrete wall panels is presented to maximize the contact area and joint friction, enhancing both the shear performance and the installation efficiency. Shear tests on eight prefabricated concrete wall panels were conducted to investigate the effects of the axial compression ratio, interface mortar strength, and keyway depth on the shear performance of these novel joints. Concurrently, a finite element model for prefabricated concrete wall panel keyway connections was established via ABAQUS, and a parametric analysis approach was employed to study various factors such as the axial compression ratio, the interface mortar strength, and the keyway construction type, as well as their impact on the shear performance of joints. The findings showed that, as the axial compression ratio increased, the failure mode of the keyway joint transitioned from shear brittle failure to compressive shear plastic failure, accompanied by evident crack propagation. The recommended keyway depth parameter remains between 40 and 80 mm, with the inclination angle of the keyway joint ideally ranging from 0° to 20°. Compared to the straight joint, the shear capacity of the innovative keyway joint increased by 16.5%.

Shear capacity of PVC-CFRP confined concrete column-RC beam interior joint strengthened with core steel tube

This paper presents an experimental investigation on polyvinyl chloride (PVC)-carbon fiber reinforced polymer (CFRP) confined concrete (PCCC) column-RC beam interior joint strengthened with core steel tube (CST). Thirteen interior joints are designed and tested under low cyclic loading considering the impacts of six variables, such as diameter-thickness ratio of CST, stirrup ratio of joint, axial compression ratio, CFRP strips spacing, reinforcement ratio of beam and reinforcement ratio of column. Distinct shear deformation in joint region finally dominates the failure of specimens. The load-displacement hysteretic curves are relatively full and eventually show inverse S shape, indicating the specimens have considerable seismic behavior and energy dissipation capacity. The yield and peak shear capacities increase as diameter-thickness ratio, stirrup ratio of joint, reinforcement ratio of column or reinforcement ratio of beam increases. Comparatively, the axial compression ratio and CFRP strips spacing exert less influence on shear capacity. Considering the impact of diameter-thickness ratio, stirrup ratio of joint and reinforcement ratio of column, a formula for estimating shear capacity of PCCC column-RC beam interior joints strengthened with CST is proposed and its accuracy is verified by test data.