C30 Concrete Research Articles

Prediction of the effective diffusion coefficient on sulfate ions in heterogeneous concrete based on Mori-Tanaka scheme

The interfacial transition zone (ITZ) between the aggregates and the matrix in concrete is the main reason for the low prediction accuracy of the effective diffusion coefficient of sulfate ions in concrete. To solve this problem, a new multi-scale prediction model of the effective diffusion coefficient for the transport of sulfate in concrete was established based on the Mori-Tanaka scheme, which fully reflects the characteristics of the imperfect ITZ, the morphological characteristics of the aggregates, the aggregate grading, and the time-varying characteristics of the content of the ITZ, the porosity and the tortuosity of the pore structure. The results showed that the prediction results of the model were basically consistent with the experimental and literature results, and the maximum error was only 20.43 %. In addition, taking the commonly used strength grades C30 and C50 concrete in engineering as examples, the changes in effective diffusion coefficient under different concentrations of sulfate erosion were predicted, showing a trend of first decreasing, plateauing, then increasing, and objectively reflecting the objective law of sulfate transport-reaction-filling-expansion damage in concrete. The predicted results confirmed that at the concentration of 3 % Na2SO4 solution, the starting time of expansion for C50 concrete is approximately 3 years later than that for C30 concrete, verifying that enhancing the concrete's strength grade significantly improves its sulfate corrosion resistance.

Study on chloride attack resistance of concrete with lithium slag content

The demand for lithium batteries in electronic products is constantly increasing, and a large amount of solid waste is generated during the production of lithium batteries. These wastes are not only harmful to the environment, but more importantly, the cost of processing the wastes is very high. To reduce the harm caused by lithium slag waste and increase the chloride ion penetration resistance of concrete, this paper designs C20, C30, C40, and C60 concrete with lithium slag contents of 0 %, 10 %, 20 %, and 30 %. The effects of different lithium slag contents on the compressive strength, electric flux, and porosity of concrete specimens were studied. The study found that for C20, C40, and C60 concrete, the compressive strength decreases with the increase of lithium slag content. For C30 concrete, the compressive strength shows a trend of increasing first and then decreasing with the increase of lithium slag content. For the electric flux of C20, C30, and C40 concrete, it shows a trend of decreasing with the increase of lithium slag content. For the porosity of C20, C30, and C40 concrete, it shows a trend of first decreasing and then increasing with the increase of lithium slag content. Combining Fick's second law and the law of conservation of mass, a chloride ion penetration model of lithium slag concrete under the action of different lithium slag contents was established. The results show that the penetration performance of chloride ions in the immersion environment conforms to the experimental law; the maximum error between the simulation results and the test results is at 360 min of C30-30LS, and the error value is 14.49 %.

Deflection characteristics and influencing factors of projectile oblique impact on concrete targets

The projectile deflects and even ricochets after an oblique impact on the concrete. However, research on the oblique impact of projectiles on concrete targets mainly focuses on oblique penetration and the critical ricochet angle, and there are few experimental studies on ricochets. Deflection and its influencing factors remain undefined. This study conducted experiments and LS-DYNA numerical simulations on projectiles obliquely impacting C60 concrete targets. The experimental research visually revealed deflection and ricochet phenomena after the oblique impact. The ricochet caused by large-angle impacts can effectively reduce the damaged area of concrete targets. Subsequently, the main governing parameters affecting the deflection angle of the projectile were identified through dimensional analysis, and a sensitivity analysis was performed on these parameters using an orthogonal experimental design. On this basis, the influence of the incident angle, impact velocity, and projectile length-to-diameter ratio on the projectile deflection was further clarified. The results showed that the maximum deflection angle was achieved when a 30 mm caliber projectile obliquely impacted a C60 concrete at an incident angle of ∼45°. In the case of ricochets, the deflection angle increased with an increase in the impact velocity and decreased with an increase in the length-to-diameter ratio. This study aids in predicting and controlling projectile deflection and provides a reference for the innovative design of concrete protective structures.

Study on the Hydration Heat Effect and Pipe Cooling System of a Mass Concrete Pile Cap

Under the action of cement hydration heat, the construction environment, thermal insulation measures, and pipe cooling systems, a mass concrete pile cap is subject to a complex internal temperature field, which makes it difficult to control its internal surface temperature difference (TISTD), the internal adiabatic temperature rise (TIATR), and the surface temperature (TST). In this study, a mass concrete pile cap of a very large bridge (the length, width, and height were 26.40 m, 20.90 m, and 5.00 m, respectively, and the central-pier pile cap was constructed with C40 concrete) was taken as the research object. The control factors affecting the temperature field of the pile cap were determined by comparing the field temperature measurements with the values calculated with finite element software simulation analysis. By using Midas Civil (2022 v1.2) and Midas FEA (NX 2022) finite element software, these factors (the concrete mold temperature, the concrete surface convection coefficient, the ambient temperature, the pipe cooling system parameters, etc.) were numerically analyzed, and their influence laws and degrees were determined.

Combined preparation and application of geopolymer pavement materials from coal slurry-slag powder-fly ash mining solid waste: A case study

The solid waste treatment problem generated in the process of coal mining has always been an important factor restricting safe and environmentally friendly production, and the coal slurry from the coal mine road surface is a new type of mine solid waste, so it is of great significance to treat and efficiently utilize the coal slurry. Currently, a common method of solid waste utilization is to add modifying reagents to prepare functional materials. Select coal slurry, slag powder and fly ash as raw materials, and sodium sulfate and sodium hydroxide were used as alkali exciters to prepare coal slurry based geopolymer pavement material (CSGPM). Response surface methodology was used to establish regression equations between the design optimization objectives (coagulation time, compressive strength) and the variables (mass fraction, mass ratio of slag powder to fly ash, mass ratio of sodium sulfate to sodium hydroxide). The effects of two-by-two interactions of the factors on the optimization objective were explored, and the use of different raw materials was obtained. Under the optimal proportioning parameters, the coagulation time of CSGPM was 33 min and the compressive strength of 24 h of curing was 11.20 MPa. In addition, the generation mechanism of AFt and C-S-H gel substances inside the specimen was explained with the help of microscopic scanning. CSGPM showed good mechanical properties in both load-bearing numerical simulations and acoustic emission tests. Numerical simulation was used to establish the relationship between the design objective of the roadbed (maximum subsidence of the roadbed after bearing) and the design variable (thickness of CSGPM paving). Comparative analyses yielded an optimal subgrade surface layer design thickness of 5 cm, with a maximum subsidence of 0.0033 m after bearing vehicles. Synchronization of roadbed material and concrete damage in combined specimen acoustic emission tests with uniform load transfer. The final coal mine pavement was successfully paved and the total cost of CSGPMD is 63.2 per cent of C30 concrete. Those results are important for the preparation of new pavement functional materials.

Numerical Analysis of the Single-Directionally Misaligned Segment Behavior of Hydraulic TBM Tunnel

The misalignment of segments in installation is a common issue in the construction of TBM tunnels. This raises a question of whether misalignment affects the operation safety of a hydraulic TBM tunnel. Using a water transfer engineering project as an example, this paper built a three-dimensional finite element model composited with segment, grout layer and surrounding rock for the numerical analysis of the behavior of single-directionally misaligned segments. The crown or invert segment was separately misaligned towards to the center of segment ring in a value of 5 mm, 10 mm, 20 mm, 30 mm or 40 mm. The strength grade of the segment concrete was C50. A weaker surrounding rock composed of V-class rock was considered for the tunnel. The results indicate that the misalignment of the crown or invert segment, respectively, creates the tensile stress in the inner surface of the corresponding segment, the tensile stress will be over the limit of C50 concrete when the misalignment is over 30 mm, indicating a risk of concrete cracking. The contact surfaces of the segment ring basically remain in compression, and the locating pins between the segment rings exhibit an evident increase in tensile stress at misaligned positions. The key points that can be obtained from this study are that a special supervision is needed to ensure the accuracy of segment installation, and strengthening measures are needed for existing misaligned segments.

Performance improvement of glass-based lightweight aggregates through thermodynamic modelling design and lightweight mortar validation

To reduce environmental impact of sintered lightweight aggregates (LWAs), in this study, novel glass-based LWAs were produced from municipal solid wastes at 900 °C. The mix was designed by thermodynamic modelling to optimize the phase composition, liquid phase properties, and microstructure of the LWAs. Results demonstrated that the inclusion of incinerated sewage sludge ash (ISSA) increased the viscosity of the liquid phase, resulting in a refined pore structure characterized by smaller, more isolated pores, and thicker pore walls. Additionally, ISSA facilitated the formation of various crystalline phases (e.g. wollastonite) to stabilize the pore structure, thereby enhancing densification and matrix strength. Leaching behaviour tests confirmed the suitability of glass-based LWAs for environmentally safe lightweight products. Lightweight mortars incorporating developed LWAs exhibited a high 28-day compressive strength (up to 57.9 MPa) with a low density of 1688 kg/m3 and a low thermal conductivity of 1.0 W/(m·K). The energy simulation revealed substantial reductions in energy consumption when the lightweight mortars were utilized in the building compared with the reference building using normal-weight C30 concrete, underscoring its promising role in conserving energy and reducing carbon emissions.

Assessment of the engineering properties of concrete prepared with aggregates developed from waste basalt mud

The development of high-performance aggregate is a key direction of sustainable concrete. One effective synthetic technology for producing artificial aggregates is hydrothermal synthesis. Using waste basalt mud from the construction of a low-carbon industrial park as a raw material further facilitates the utilization of solid waste resources. Therefore, this paper adopted the hydrothermal synthesis method to produce artificial aggregates developed from basalt mud (AABM). Subsequently, it was used to partially replace mechanical aggregate in the preparation of concrete with strength grad C30. The engineering properties of concrete prepared with AABM (C-AABM), including workability, densities, mechanical properties, and frost resistance, were investigated to assess the feasibility of using AABM as concrete aggregates. The results showed that the fluidity of C-AABM can be significantly improved by using AABM. The hardened C-AABM, prepared with 10 ∼ 30 vol% AABM instead of mechanized aggregate, exhibited a dry density decrease of less than 5 %, indicating the feasibility of using AABM for ordinary concrete. However, excessive AABM negatively affected the mechanical properties of the concrete. When the AABM substitution was no more than 15 vol%, the impact of AABM on the compressive strength and modulus of elasticity of C-AABM was less than 15 %. Nevertheless, the performance of the concrete deteriorated dramatically with the addition of AABM under freezing conditions. As described, the primary engineering advantage of preparing C30 concrete with AABM is to improve the workability of the fresh matrix without significantly reducing the mechanical properties of the hardened concrete. It proves the viability of AABM as an alternative aggregate for ordinary concrete production.

Research on the optimal design of roadway support for fully mechanized coal seam working face

Abstract For the optimal design of surrounding rock deformation and support in the shallow buried coal seam of large-scale fully mechanized mining face, this paper took the surrounding rock of the roadway as the research object, used theoretical calculation and numerical simulation to establish the mechanical model of the deformation of the surrounding rock structure, and proposed and analyzed the reasonable roadway support scheme of the shallow buried coal seam. The numerical simulation results showed that the top anchor rod with Φ18×2200 mm and the inter-row distance of 1100×1000 mm, the anchor cable with Φ15.24×6300 mm and the inter-row spacing of 2200×2000 mm, the upper part anchor of Φ16×2200 mm, and the C30 concrete with a thickness of 200 mm for laying the bottom plate are selected, which was certified as the optimal support scheme. In practical engineering applications, the deformation of surrounding rock has been effectively controlled, and the supporting effect of surrounding rock was obvious, which was of great significance to ensure the safe production of coal mines.

Investigation on the mechanical properties of Bacillus subtilis self-healing concrete

In the process of research and development of self-healing concrete, it is observed that there are three main factors controlling the self-healing effect of concrete: first, the bacteria with repair ability and strong vitality; Second, the carrying capacity of the carrier and the matching degree with concrete; The third is the concentration of bacteria. This paper focuses on the mechanical properties of Bacillus subtilis self-healing concrete with sisal fiber, PVA, and expanded perlite as the carrier. To better study the mechanical properties of self-healing concrete caused by the carrier, the experiment adopts the design parameters of C30 concrete and conducts experiments on compressive resistance, flexural resistance, freeze-thaw cycle, and sulfate corrosion resistance to analyze the influence of different carriers on the mechanical properties of self-healing concrete, and obtains the best carrier. The concentration gradients of three groups of bacterial solution were set as 2od, 2.5od, and 3od, respectively, for comparison to avoid the influence of bacterial concentration. It compared the impact of bacterial solution concentrations on the specimen's mechanical properties, and the effect of carriers was also analyzed. The experimental results show that the mechanical properties of the specimen using 2.5od bacterial liquid concentration with PVA as the carrier have peaked. With the increase in bacterial solution concentration, the specimens' comprehensive mechanical properties increased first and then decreased. The compression resistance of the specimen with PVA is higher than that of the specimen with sisal fiber and expanded perlite. At the same time, the frost resistance and corrosion resistance of the PVA carrier specimen is also higher than that of the specimen with sisal fiber and expanded perlite carrier.

Using BIM and LCA to Calculate the Life Cycle Carbon Emissions of Inpatient Building: A Case Study in China

Hospital buildings provide healthcare services at the costs of significant amounts of energy consumption and carbon emissions, further exacerbating the environmental load. Because of the limited research on the life cycle carbon emissions of Chinese hospitals, this study conducted a detailed carbon-accounting and comparative study. Firstly, BIM and LCA were used to quantify the carbon emissions of the inpatient building in each stage of the life cycle. Secondly, the differences in carbon emissions by stage were compared on the basis of 20 cases of public buildings. The results show that the whole-life carbon emissions of the inpatient building was 10,459.94 kgCO2/m2. The proportion of operational carbon emissions was 94.68%, with HVAC (52.57%), equipment (27.85%), and lighting (10.11%) being the main sources. Embodied carbon emissions accounted for 4.54%, and HRB400 steel and C30 concrete were the main sources of carbon emissions. Hospitals are second only to emporiums in terms of operational carbon intensity, being 1.71 and 1.41 times that of schools and office buildings, with inpatient buildings being 3 and 1.7 times that of medical complexes and outpatient buildings, respectively. The future sustainable development of hospital buildings should promote efficient building performance and good environmental quality, both in terms of energy efficiency and carbon reduction.

The influence of slag content on the mechanical properties of high-strength concrete

In light of the current situation where excessive amounts of excavated earth from subway tunnel construction are being stacked with low utilization and value, this study used residue as a mineral admixture to investigate the effects of different proportions of residue content (0%, 2.5%, 5.0%, 7.5%, and 10.0%) on the workability and mechanical properties of C50 concrete. The results indicate that: (1) The initial slump and slump loss of C50 concrete decrease gradually as the residue content increases. (2) The compressive strength of C50 concrete with varying residue contents is lower than the control group at early stages (3d, 7d), while it is higher than the control group at 28d. There exists an optimal content of residue for improving C50 concrete compressive strength, and it is found that the highest compressive strength at 28d is achieved when the residue content is 7.5% of the cement content. (3) The microscopic structure of C50 concrete with different residue contents at 28d shows that as the residue content increases, the microscopic structure of C50 concrete gradually becomes more compact and the porosity decreases.

Frost-Resistance Assessment of C60 Concrete Based on a Fiber Bragg Grating Sensor

Frost-Resistance Assessment of C60 Concrete Based on a Fiber Bragg Grating Sensor

Reduction in the Constrained Shrinkage and Crack Risk of Different-Strength-Level Concretes with Saturated Ceramsite

To reduce the shrinkage and cracking risk of concrete, internal curing technology was applied to modify concretes with different strength levels (C30 and C60) by incorporating saturated ceramsite. Three kinds of tests were carried out to study the effects of the incorporation of saturated ceramsite on the compressive strength, hydration temperature rise, and shrinkage behavior of the concretes, respectively. It was found that the internal hydration temperature rise of the concrete could be delayed and reduced due to the internal curing effect of ceramsite. Moreover, both the early-stage and long-term constrained shrinkage behavior of the internal cured concretes were monitored with embedded strain sensors and compared with free shrinkage behavior. For the C30 concrete system, with the incorporation of saturated ceramsite, its constrained shrinkage at 96 h was reduced greatly from 181 µε to 36 µε. Furthermore, the surface-attached-sensor method was also used to study the shrinkage behavior of the concrete beams and it was found that the sensor location affected the measured shrinkage values greatly. The model beams of both the C30 and C60 concrete systems shrunk significantly in the first month, and the highest cracking risk occurred in this period as well. The internal curing effect of saturated ceramite could significantly reduce the constrained shrinkage of the concrete beam, evidently diminishing the cracking risk. More importantly, compared to the ordinary concrete C30 system, it was revealed that such an internal curing effect was more effective in promoting the performance of the higher-strength concrete (C60). With this effect, the cracking risk of C60 concrete was reduced from 0.69 to 0.37 at 300 days and changed little from then on.

Steel corrosion process in ultra-high performance concrete monitored by fiber bragg grating sensor

The steel corrosion in Ultra-High Performance Concrete (UHPC) would cause degradation of structural performance or even structural failure. It is an urgent need to monitor and predict the steel corrosion in UHPC, however it is still a tough task. In this paper, Fiber Bragg Grating (FBG) sensors are applied for monitoring the steel corrosion process in UHPC, by combining with steel bar, which is equidistant winding with the sensors, and connected with power supply for accelerating corrosion. The UHPC specimens embedded with steel bars are surrounded by sodium chloride (NaCl) solution, and the steels are artificially corroded with different current densities for investigation. The steel corrosion in Original C60 and Marine Concrete 60 (Marine C60) are applied for comparison. The volume expansion coefficient for monitoring the steel corrosion process, is carried out by FBG sensors, and further comprehensively monitored by three grating sensors. The results suggest that the steel corrosion process in UHPC is slowly with current density lower than 100 μA/cm2, and largely increases with current density higher than 500 μA/cm2, the volume expansion coefficient of corroded steel in UHPC is in range of 2.02–2.62 in this test, which is much different from Original C60 and Marine C60.

Experimental study on the preparation of wood aggregate recycled concrete using waste wood and recycled fine aggregate from construction and demolition wastes

As a renewable resource, wood has the advantages of a high strength-weight ratio, high yield and excellent thermal insulation. Meanwhile, the resource utilization of large quantities of waste wood, waste furniture and mixed wood generated by the demolition of old houses and the removal of building formwork are basically in a blank state. Therefore, in this study, construction solid waste—waste wood and recycled fine aggregate were used as coarse and fine aggregates to replace natural sand and gravel, respectively, and synergized with three cementitious materials (sulfoaluminate cement, portland cement and geopolymer cement) to prepare wood aggregate recycled concrete (WARC). Focus on the evolution law of basic property, thermal insulation property, mechanical property, shrinkage property, environmental and economic benefits of WARC. The results showed that the mechanical and shrinkage properties of WARC were deteriorated by using WA and recycled fine aggregate (RFA) instead of natural aggregates. The dry density of WARC was as low as 1770 kg/m3. The 28 d maximum compressive and flexural strength were 34.8 and 5.69 MPa, which were better than traditional C30 concrete. Compared with conventional concrete, WARC has excellent thermal insulation properties. The thermal conductivity was reduced by up to 81.9 % compared to traditional concrete, which would make WARC very promising for non-structural components (green insulated wall materials and precast wall panels, etc.). By calculating CO2 emissions and compressive strength-cost efficiency values, it was found that the WARC prepared with geopolymer cement could reduce CO2 emissions by 31.3 % while possessing good mechanical properties and economic benefits, making it the optimal cement-based material for preparing WARC.

A Sustainable Steel-GFRP Composite Bars Reinforced Concrete Structure: Investigation of the Bonding Performance

Steel-fiber reinforced polymer (FRP) composite bars (SFCBs) can enhance the controllability of damage in concrete structures; thus, studying the interfacial bonding between them is fundamental and a prerequisite for achieving deformation coordination and collaboration. However, research on the interfacial bonding performance between SFCBs and concrete remains inadequate. This study conducted central pullout tests on SFCB-concrete specimens with different concrete strengths (C30, C50, and C70), bar diameters (12, 16 and 20 mm), and hoop reinforcement constraints, analyzing variations in failure modes, bond-slip curves, bond strength, etc. Additionally, finite element simulations were performed using ABAQUS software to further validate the bonding mechanism of SFCB-concrete. The results showed that the failure mode of the specimens was related to the confinement effect on the bars. Insufficient concrete cover and lack of hoop restraint led to splitting failure, whereas pullout failure occurred otherwise. For the specimens with pullout failure, the interfacial damage between the SFCB and concrete was mainly caused by the surface fibers wear of the bar and the shear of the concrete lugs, which indicated that the bond of the SFCB-concrete interface consisted mainly of mechanical interlocking forces. In addition, the variation of concrete strength as well as bar diameter did not affect the bond-slip relationship of SFCB-concrete. However, the bond strength of SFCB-concrete increased with the increase of concrete strength. For example, compared with C30 concrete, when the concrete strength was increased to C70, the bond strength of the specimens under the same conditions was increased to 50–101.6%. In contrast, the bond strength of the specimens decreased by 13.29–28.71% when the bar diameter was increased from 12 to 14 mm. These discoveries serve as valuable references for the implementation of sustainable SFCB-reinforced concrete structures.

EXPERIMENTAL STUDY OF THE CHLORIDE-ION PERMEABILITY OF BAMBOO-FIBER-REINFORCED CONCRETE

This study investigated the chloride-ion permeability of C30 concrete by adding bamboo fibers with different treatments (untreated, treated with calcium hydroxide solution and treated with sodium hydroxide solution) and different dosages. Three testing methods, namely the electric-flux method, AC test method and the RCM method, were used to characterize the concrete. Parameters such as electric-flux value, AC resistivity and chloride-ion diffusion coefficient were obtained. Results showed that the surface impurities of the bamboo fibers treated with calcium hydroxide solution were removed and the thermal stability of the bamboo fibers was improved, which can effectively enhance the chloride-ion permeability of concrete. Compared to untreated bamboo fibers, the improvement rate was between 14 % and 17 %. Sodium hydroxide is a strong alkaline solution, which can easily disrupt the structure of bamboo fibers and reduce the resistance of concrete to chloride-ion penetration. The best chloride-ion permeability was achieved when the bamboo fiber content reached 2 %. The electric-flux method, AC test method, and the RCM method were mutually validated with good correlation. It is recommended to choose a suitable and simple method for testing. Bamboo-fiber concrete lays a solid foundation for the future transformation of the civil-engineering industry.

Mechanism of interface debonding in steel-concrete components caused by thermal expansion and contraction

The steel tube concrete structure constrains the core concrete through the inner wall of the steel tube, forming a hoop effect, significantly improving the compressive performance of the core concrete and effectively exerting the tensile performance of the steel tube. Although this structure has been optimized in terms of mechanical properties, its ultra-high bonding performance makes it extremely difficult to disassemble and recycle. To explore ways to solve this challenge, this article selects C40 concrete as the matrix concrete, and designs and produces circular steel tube concrete specimens and square steel tube concrete specimens with a height of 250mm and a steel tube wall thickness of 4mm. The specific research content covers the hoop effect of steel pipes on core concrete, the degradation law of thermal expansion and contraction interface bonding performance of steel pipe concrete components, the coupling effect of cutting joints and thermal expansion and contraction on interface bonding performance of steel pipe concrete components, and the mechanism of interface debonding of steel pipe concrete components. Through systematic experiments and analysis, the influence of different variation parameters on the debonding performance of steel tube concrete was deeply studied, and its debonding mechanism was revealed. This series of studies provides an important scientific basis for the theoretical understanding and application of steel-concrete structures, helping to overcome the problem of dismantling and recycling, and promoting the transformation and development of related equipment.

Axial-compression performance and numerical-simulation analysis of steel tube coal gangue concrete column

Coal gangue is a solid waste produced in the process of coal mining, excessive accumulation will occupy land and pollute the environment. It is one of the most effective means to realize comprehensive utilization of coal gangue by replacing some aggregates in concrete and applying it to engineering structures. In this paper, based on C30 concrete, by changing the replacement rate of coal gangue, slenderness ratio, and steel pipe wall thickness, 17 Coal gangue concrete-filled steel tubular (CGC-FST) columns were designed and made, and the axial compression tests were carried out. The results show that the failure mode of the CGC-FST column is similar to that of CFST, and the annular band shear buckling occurs on the wall of the steel pipe, and the higher the slenderness ratio, the more the number of buckling in the middle. With the increase of coal gangue substitution rate, the ultimate bearing capacity of the CGC-FST column decreases gradually, and the ductility of the specimen decreases slightly. The increase in slenderness ratio reduces the ultimate bearing capacity of the member, the failure form changes from material failure to stable failure, and the material properties are not fully utilized. The most obvious way to improve the bearing capacity and ductility of gangue steel tube members is to increase the steel content. Through the finite element simulation analysis of more working conditions of the CGC-FST column, the calculation formula of the bearing capacity of the CGC-FST column is fitted, which can effectively predict the bearing capacity of the CGC-FST column in a certain range.