Beam Height Research Articles

Experimental Investigation on Shear Behavior of Non-Stirrup UHPC Beams under Larger Shear Span–Depth Ratios

Due to the extraordinary mechanical properties of ultra-high-performance concrete (UHPC), the shear stirrups in UHPC beams could potentially be eliminated. This study aimed to determine the effect of beam height and steel fiber volume content on the shear behavior of non-stirrup UHPC beams under a larger shear span–depth ratio (up to 2.8). Eight beams were designed and fabricated including six non-stirrup UHPC beams and two comparing stirrup-reinforced normal concrete (NC) beams. The experimental results demonstrated that the steel fiber volume content could be a crucial factor affecting the ductility, cracking strength, and shear capacity of non-stirrup UHPC beams and altering their failure modes. Additionally, the height of the beam had a considerable effect on its shear resistance. French standard formulae were more accurate for the UHPC beams with larger shear span–depth ratios, PCI-2021 formulae greatly overestimated the shear capacity of UHPC beams with larger shear span–depth ratios, and Xu’s formulae were more accurate for the steel fiber-reinforced UHPC beams with larger shear span–depth ratios. In summary, French standard formulae were the most suitable formulae for predicting the shear capacity of UHPC beams in this paper.

Reanalysis of multi-year high-resolution X-band weather radar observations in Hamburg

Abstract. This paper presents an open-access data set of reanalysed radar reflectivities and rainfall rates at sub-kilometre spatial and minute temporal scales. Variability at these scales is a blind spot for both operational rain gauge networks and operational radar networks. In the urban area of Hamburg, precipitation measurements of a single-polarized X-band weather radar operating at high temporal (30 s), range (60 m), and azimuthal sampling (1°) resolutions are made available for a period of more than 8 years. We describe in detail the reanalysis of the raw radar data, outline the radar performance for the years 2013 to 2021, and discuss open issues and limitations of the data set. Several sources of radar-based errors were adjusted gradually, affecting the radar reflectivity and rainfall measurements, e.g. noise, alignment, non-meteorological echoes, radar calibration, and attenuation. The deployment of additional vertically pointing micro rain radars yields drop size distributions at the radar beam height, which effectively reduces errors concerning the radar calibration and attenuation correction and monitors the radar data quality. A statistical evaluation revealed that X-band radar reflectivities and rainfall rates are in very good agreement with the micro rain radar measurements. Moreover, the analyses of rainfall patterns shown for an event and accumulated rainfall of several months prove the quality of the data set. The provided radar reflectivities facilitate studies on attenuation correction and the derivation of further weather radar products, like an improved rainfall rate. The rainfall rates themselves can be used for studies on the spatial and temporal scales of precipitation and hydrological research, e.g. input data for high-resolution modelling, in an urban area. The radar reflectivities and rainfall rates are available at https://doi.org/10.26050/WDCC/LAWR_UHH_HHG_v2 (Burgemeister et al., 2024).

Seismic performance of the WCFTC-beams joint with high-strength double-side plates

This research presents a novel joint design for wall-type concrete filled steel tube (WCFTC) beams, integrated with high-strength double-side plates, resolving the problem of traditional side plate extending from the wall and interfering with wall panel installation. The study synthesizes a reliable finite element (FE) model corroborated by previous experimental analyses, enabling a detailed parametric study on the dimensions of the side plates. Comprehensive analysis assessed the impact of steel plate thickness and material strength on the joint's seismic properties, uncovering that the innovative joint design reduces steel usage while maintaining load capacity. Subsequent full-scale testing of prototypes under cyclic loading revealed the failure modes and hysteresis responses, which exhibited notable energy dissipation reflected in ductility coefficients exceeding 3.0. The study also identifies the plastic hinge location to be at a distance ranging from 1.0 to 1.5 times the beam's height from the column's edge, validating the efficacy of the joint design categorized as full-strength or rigid. Furthermore, comparative assessments of Q690D and Q460C steel plates indicated similar performance, suggesting a flexibility in high-strength material choice without loss of joint integrity. The culmination of the study is the proposal of a clear and actionable design method, predicated on the synthesized findings, offering a pragmatic reference for designers and engineers in the field. This method aims to streamline the adoption of this advanced joint construction for enhanced seismic resilience in structural applications.

Experimental research on shear resistance performance of fabricated reinforced concrete layered beams

The construction of prefabricated beams includes two steps: prefabrication and cast in-situ. However, for the bearing beam, the shear stress on the joint surface of these two parts may be large. This is detrimental to the shear resistances of layered beams. To evaluate the shear resistance performances of such layered beams, three different influencing factors—the ratio of the precast layer height to the beam height, shear-span to depth ratio, and the treatment method of new and old concrete interface—were considered, and shear resistance tests of 9 groups of beams were carried out. The failure mode, carrying capacity, deflection, and strain value of each test beam were analyzed. The results show that the shear bearing capacity of layered beams decreases by 34.12% with the increase of shear-span to depth ratio, and with the increase of the ratio of precast layer height to beam height, the shear bearing capacity of layered beams decreases by 14.17%. The shear bearing capacity of the layered beam with steel bars inserted in the vertical direction of the new and old concrete interface is about 8.43% higher than that of the layered beam without steel bars. According to the test results, the formula for calculating the shear bearing capacity of layered beams considering the layered height ratio and shear-span to depth ratio was proposed. At the same time, the interface resistant shear design method concerning reinforced concrete layered beams is proposed.

Elastic lateral-torsional buckling of cellular beams

Cellular beams are I-shaped steel sections with advantages provided by their circular web openings. This type of beam can have greater spans, be more slender and higher than the solid beams, being more prone to failure by lateral-torsional buckling. Given there is still no specific standard for cellular beams and owing to the importance of safety verification, this paper numerically investigated the lateral-torsional buckling of these beams. Considering the torsional constant as the most important parameter in the design of web-opening beams, this study proposes a new torsional constant and approaches four different calculation methods of weighted average torsional constants. The elastic critical moment of cellular beams was numerically modelled using ANSYS software and compared with analytical results according to European standards, varying the torsional constants. The weighted average torsional constant based on an equivalent area and using the proposed torsional constant was the most efficient, showing the best analytical results when compared with the numerical ones considering the load condition of constant bending moment. Furthermore, from all the geometric parameters evaluated, the height of the cellular beam was what most influenced the elastic critical moment of the cellular beams.

Mechanical behavior of ECC-reinforced coupled shear wall

PurposeBased on the weak seismic performance and low ductility of coupled shear walls, engineered cementitious composites (ECC) is utilized to strengthen it to solve the deformation problem in tall buildings more effectively and study its mechanical properties more deeply.Design/methodology/approachThe properties of reinforced concrete coupled shear wall (RCCSW) and reinforced ECC coupled shear wall (RECSW) have been studied by numerical simulation, which is in good agreement with the experimental results. The reliability of the finite element model is verified. On this basis, a detailed parameter study is carried out, including the strength and reinforcement ratio of longitudinal rebar, the placement height of ECC in the wall limb and the position of ECC connecting beams. The study indexes include failure mode and the skeleton curve.FindingsThe results suggest that the bearing capacity of RECSW is significantly affected by the ratio of longitudinal rebar. When the ratio of longitudinal rebar increases from 0.47% to 3.35%, the bearing capacity of RECSW increases from 250 kN to 303 kN, an increase of 21%. The strength of longitudinal rebar has little influence on the bearing capacity of RECSW. When the strength of the longitudinal rebar increases, the bearing capacity of RECSW increases little. The failure mode of RECSW can be improved by lowering the casting height of the ECC beam in a certain range.Originality/valueIn this paper, ECC is used to strengthen the coupled shear wall, and the accuracy of the finite element model is verified from the failure mode and skeleton curve. On this basis, the casting height of the ECC casting wall limb, the strength and reinforcement ratio of longitudinal rebar and the position of the ECC beam are studied in detail.

Experimental and numerical research on shear performance of GFRP bar reinforced seawater sea-sand concrete deep beams without stirrups

Using glass fibre-reinforced polymer (GFRP) bars to reinforce seawater sea-sand concrete (SWSSC) is a feasible way to replace traditional concrete structures. Thus, this paper aims to understand the shear response of GFRP bar-reinforced SWSSC (GFRP-SWSSC) deep beams. Experimental and numerical programs were carried out on four-point shear tests of GFRP-SWSSC deep beams without stirrups. Seventy specimens were tested to investigate the effects of key parameters on shear responses, including concrete categories, seashell content, section heights, and GFRP bar diameter. The test results indicated that the cracking strength of GFRP-SWSSC deep beams was slightly higher than ordinary concrete deep beams. The increased section height of GFRP-SWSSC deep beams and the decreased shell content remarkably enhanced the stiffness and shear ultimate strength. The corresponding finite element model (FEM) of GFRP-SWSSC specimens was established and validated by comparison with test results. Further, three guidelines predictions for the shear strength of GFRP-SWSSC beams were too conservative. The new design formulae derived from modified tension-compression theory were put forward to evaluate the shear strength of GFRP-SWSSC deep beams, and the comparisons demonstrated that the proposed design formulae achieved sufficient accurate predictions for practical engineering. Based on research on shear performance, the hybrid GFRP-SWSSC structure is a feasible solution to resource shortages, which provides a promising application prospect in marine engineering.

Application of Modified Couple-Stress Theory to Nonlinear Vibration Analysis of Nanobeam with Different Boundary Conditions

PurposeIn the present study, the nonlinear vibration analysis of a nanoscale beam with different boundary conditions named as simply supported, clamped-clamped, clamped-simple and clamped-free are investigated numerically.MethodsNanoscale beam is considered as Euler-Bernoulli beam model having size-dependent. This non-classical nanobeam model has a size dependent incorporated with the material length scale parameter. The equation of motion of the system and the related boundary conditions are derived using the modified couple stress theory and employing Hamilton’s principle. Multiple scale method is used to obtain the approximate analytical solution.ResultNumerical results by considering the effect of the ratio of beam height to the internal material length scale parameter, h/l and with and without the Poisson effect, υ are graphically presented and tabulated.ConclusionWe remark that small size effect and poisson effect have a considerable effect on the linear fundamental frequency and the vibration amplitude. In order to show the accuracy of the results obtained, comparison study is also performed with existing studies in the literature.

Experimental and theoretical investigation into flexural performance of thin-walled steel-laminated bamboo lumber truss beam

This study presents a novel truss beam called thin-walled steel-laminated bamboo lumber truss beam (SBTB). The SBTB is composed of cold-formed thin-walled steel chords and laminated bamboo lumber web members. A total of 24 SBTBs were divided into eight groups, each group containing 3 specimens, to investigate various parameters, including bamboo web member thickness and laminated direction, number of self-drilling screws, shear span ratio, and truss beam height and width. The flexural performance of SBTBs was evaluated through a four-point bending test, analyzing the failure mode, deflection, bearing capacity, and bending stiffness. The impact of different parameters on the flexural performance was thoroughly examined and discussed. In addition, a theoretical model and simplified prediction approach for the bending stiffness of SBTBs were developed. The results identified five failure modes during the flexural tests and demonstrated the linear elastic and nonlinear stages of the SBTB working process. Increasing the width and height of the beam, the number of self-drilling screws, and adopting plain pressed laminated bamboo lumber web members significantly improved the bending resistance of the composite truss beam. Notably, the theoretical model accurately predicted the stiffness of SBTBs, with a maximum discrepancy of less than 12.3 % between experimental and theoretical results.

Experimental study and optimal design of UHPC T‐shaped beam

AbstractIn this paper, the ordinary reinforced UHPC T‐shaped beam, steel plate reinforced UHPC T‐shaped beam and prestressed UHPC T‐shaped beam were compared by conducting the flexure test. The vertical displacement, crack development, strain change, and crack resistance were discussed. The steel plate reinforced UHPC T‐shaped beam shown better cracking resistance and mechanical properties. Based on the research, the multi‐scale finite element model of the steel plate reinforced UHPC T‐shaped beam was established, and the influence parameters were analyzed. The beam height, steel plate thickness and web thickness shown great influence on the ultimate bearing capacity of the beam. The bearing capacity calculation formulas of the steel plate reinforced UHPC T‐shaped beam based on the plastic strengthening model of the steel were proposed. The calculation results shown good agreement with the test value.

Experimental study on flexural behavior of steel-laminated concrete (NC and UHPC) composite beams with corrugated steel webs

The challenges of the substantial self-weight in prefabricated bridge deck slabs, the presence of numerous scattered steel beam components, and the low durability of bridge deck slabs have long been difficult issues to address in the context of traditional prefabricated steel-normal concrete (NC) composite girder bridges with flat steel webs. This paper proposes a solution through the optimization of structural forms and material properties by introducing a novel structural configuration as prefabricated steel-laminated concrete (LC) composite girder bridges with corrugated steel webs. The flat steel webs were substituted with corrugated steel webs, and the LC bridge deck slab was composed of a NC layer and an ultra-high performance concrete (UHPC) layer. This paper conducted three groups of experimental tests to comparatively analyze the effects of web forms and bridge deck materials on the flexural performance of composite beams. The results indicate that, under the conditions of consistent beam height and steel usage, composite beams with corrugated steel webs have fewer steel components, better stability, and smaller difference in bearing capacity compared to composite beams with flat steel webs. Compared with NC bridge deck slab, laminated bridge deck slab can increase the stiffness and bearing capacity of composite beam by about 13%, and the thickness of the bridge deck slab can be reduced by 20%. Furthermore, this paper presents a shear connection degree calculation method suitable for composite beams with corrugated steel webs, which effectively reduces the number of connectors.

Experimental investigation of the effect of horizontal construction joints on the behavior of deep beams

Abstract Construction joints serve as interruption points in the concrete placement process, which is necessary because it is often not feasible to pour concrete continuously in many structures. The quantity of concrete that can be poured at a single instance depends on the batching and mixing capacity, as well as the strength of the formwork. An effective construction joint must ensure sufficient flexural and shear continuity across the junction. Many studies investigated the construction joints in the reinforced concrete (RC) normal beams, but there are no studies investigating the effect of construction joints on the behavior of the RC deep beams. This study was prepared to show the behavior of deep beams having horizontal construction joints (HCJs) extended through their entire length. The parameter studied in this research was the location of the HCJ within the beam height. Four simply supported RC deep beams were tested under a two-point static load up to failure. One of these beams was without a construction joint and was considered a reference beam. Each one of the other beams has only one horizontal construction. The location of these joints was below, at, or above the beam mid-height. The crack patterns, the strain distributions, the mode of failure, deflection, and failure load are discussed. It was found that the existence of construction joints below, at, or above the beam mid-height results in a decrease in load failure load by 9, 11, and 1% compared with the reference beam. It can be concluded that the best location of the HCJ in the RC deep beam is in the upper part of the beam.

Experimental investigation on strengthening lap joints subjected to bending in glulam timber beams using CFRP sheets

Abstract Strengthening the carpentry joints is considered a big challenge for designers to maintain the joined timber elements’ load transfer and integrity. This research work investigates different techniques to strengthen the lap joints in glulam timber beams using carbon fiber-reinforced polymer (CFRP) sheets. For this purpose, 12 specimens of glulam timber beams were tested using the four-point loading method. One of the glulam timber specimens was an intact nonlapped specimen, and the others were lapped at mid-span using half-height lap joints. The lap joints were strengthened using different configurations of the CFRP sheets. The test variables were the clamping scheme, bond length, and reinforcement ratio of the CFRP sheets. The analysis of the test results indicates that the CFRP strengthening configuration could be more effective in strengthening the lapped glulam timber beams when the reinforcement ratio of the longitudinal CFRP sheets was equal to 0.303%, and the wrapping CFRP sheets continued beyond the lapped joint by a distance equal to the beam height. Such a strengthening configuration could succeed in increasing the effective stiffness and ultimate load of the lapped timber specimen to 109 and 110%, respectively, relative to those of the intact nonlapped specimen. Moreover, the results reveal that increasing the length or the reinforcement ratio of the longitudinal CFRP sheets without increasing the width of the wrapping CFRP sheets could not succeed in achieving the required improvements in the structural behavior of the lapped timber beams.

Design method of irregular-shaped concrete-filled steel tube column joints with inner semi-diaphragm

This paper studies the mechanical behavior and design method of the irregular-shaped concrete-filled steel tube column to H-shaped steel beam joints with inner semi-diaphragm (ICFSTC-Joint) by numerical and theoretical investigation. ICFSTC-Joint was proposed and tested in the authors’ previous paper, which can be adopted in steel-concrete composite structures. Firstly, the tensile and compressive bearing capacity of ICFSTC-Joint under the tension or compression of a single beam flange is investigated. Secondly, based on the tensile and compressive bearing capacity, the bending capacity of the ICFSTC-Joint under the bending exerted by a complete H-shaped beam is investigated. Finally, the interaction between multiple ICFSTC-Joints is considered. The FE model verified by the hysteretic experiment of ICFSTC-Joint is adopted in the parameter analysis. The parameter analysis involves the height of beam, width and thickness of beam flange, height and thickness of diaphragm, thickness of column wall, length of column limb and axial compressive ratio. Based on the parameter analysis results, the mechanical models of ICFSTC-Joint under various conditions are established. The complete set of design method as well as some constructional requirements are finally established through the theoretical derivation of mechanical models and fitting the FE investigation results and exhibit good precision.

ЭЛЕМЕНТЫ ОЦЕНКИ РЕСУРСА СТАЛЬНЫХ БАЛОК, ПРЕДВАРИТЕЛЬНО НАПРЯЖЕННЫХ ВЫТЯЖКОЙ СТЕНКИ

The article presents possible ways to determine service life of steel single-span beams with prestressed web. The authors implement the method for searching coefficients of optimal distribution of material over the cross section of a symmetrical, monometallic steel I-beam. Basing on structures theory the study determines the maximum permissible moments of external loads for ordinary and prestressed beams. It formulates analytical expressions characterizing the first and second limit states of prestressed beams and establishes the resource of their bearing capacity. As a result of performed analysis, analytical dependences of prestressed beams stiffness are determined and structures resource is established according to this criterion. The study determines height of beams and its change with span variations and actual uniformly distributed load. Resource height of prestressed beams is established in comparison with height of conventional bending structures. Load-bearing capacity of beams with prestressed web is 1,8 times higher than the corresponding capacity of conventional beam and their resource is 180 %. Deflections of prestressed beams are 77,3 % less than deflections of traditional beams and stiffness resource is 1,29. Height of conventional beam is 1,847 times higher than height of prestressed structure. Service life of prestressed beam is 187%. Key words: prestressing, optimal design, load-bearing capacity, rigidity, service life.

Experimental Study on Fatigue Performance of Composite Box Girder With Steel Bottom Plate and Corrugated Steel Webs

In order to study the fatigue performance and fatigue failure mode of the composite box girder with steel bottom plate and corrugated webs (SBCSWs), the model beam was made and the constant and variable amplitude fatigue experiment were performed. Combined with ABAQUS finite element software, the strain, deflection, and fatigue failure mode of the composite box girder with SBCSWs were analyzed. The results showed that the slope of the load–deflection curve, the slope of the load–strain curve, and the neutral axis height of the model beam did not change during the constant amplitude fatigue test. In the variable amplitude fatigue test, as the fatigue loading time and fatigue load amplitude increased, the slope of the load–deflection curve and the slope of the load–strain curve of the model beam decreased significantly, while the neutral axis height increased significantly. The section strain of the composite box girder with SBCSWs was consistent with the quasi‐plane section assumption. The fatigue failure of the composite box girder with SBCSWs began at the stress concentration at the junction of the steel bottom plate and the corrugated webs. The fatigue fracture section has typical fatigue fracture characteristics.

Investigating Reinforced Concrete Beams with Web Opening under Static and Cyclic Loads

This study aims to investigate experimentally and theoretically the behavior of reinforced concrete beams with openings subjected to static and cyclic loads. The experimental program consists of testing eight specimens with a rectangular opening at the shear zone, two of the beams serve as a control beam (without openings) subjected to static and cyclic loads, three beams with rectangular openings of variable height and subjected to static loads, and three beams with rectangular openings of variable height and subjected to cyclic loads. All openings were rectangular of constant length and varied at heights of 20%, 30%, and 40% of the beam height. The beams were loaded at two points using a steel plate until the failure stage was reached. Numerical studies were performed on ANSYS software, and the finite element results were verified through experiments. The response has been discussed in terms of the deformation occurring in all beams, the crack pattern, and failure modes, resulting from static and repeated loading. Results indicated that the load failure of the beams subjected to cyclic loads decreased by a rate ranging from 86% to 90% of those static loads. The results also showed that the load failure rate decreases as the opening height increases. The percentages of decrease were (58%, 62%, and 90%) compared to the load failure rate of the control beam (without opening), which corresponds to opening heights of 20%, 30%, and 40% of the beam’s height.

Flexural capacity and serviceability evaluation on seawater sea-sand concrete beams reinforced by BFRP bars and TRE composite in the dry-wet environment

To promote the durability and serviceability of offshore structures, the bearing capacity and serviceability of BFRP-reinforced seawater sea-sand concrete (SWSSC) beams with textile reinforced ECC (TRE) to retard deformation and cracking under chloride dry-wet cycles were investigated. A total of a BFRP-reinforced SWSSC beam and nine TRE composite beams were designed. The dry-wet cycles, thickness, fabrication method and shape of TRE composite layer as factors the on the bearing capacity, deflection and crack behavior, curvature and ductility of beams with TRE composite were analyzed. TRE composite layer still can visibly increase the cracking moment of BFRP-reinforced SWSSC beams even in the dry-wet conditions, but the improvement effect on the ultimate moment was noteless. The bearing moments of composite beams increased with the TRE thickness and the dry-wet cycles. The failure modes for composite beams with the same reinforced radio of FRP bars under dry-wet environment changed from failure in shear cross zone to failure in pure bending zone with the increase of the thickness of TRE composite layer. The development of deformation and cracks for beams with TRE composite was significantly distinct from that for BFRP-reinforced SWSSC beams, attributed to the bonding properties of the composite layer to concrete, which with the TRE composite subjected to service moments can be judged by the curvature of 0.00375/d, below the curvature of 0.005/d. The fine cracks in TRE composite beams developed sequentially throughout the pure bending of beams. The dry-wet environment can reduce the deflection by increasing the stiffness of beams. Under service moment, the neutral axis height of TRE composite beam was clearly superior to that of BFRP-reinforced SWSSC beam. The variation trend of ductility index on energy and deformation was different. And the ductility of TRE composite beams declined as the increasing dry-wet cycles, regardless of the energy or deformation.

An Adaptive Crack Width Prediction for Flexural Steel Reinforced UHPC Beams

The crack pattern of steel reinforced ultrahigh performance concrete (UHPC) beam is usually characterized by many densely distributed fine cracks (i.e., multiple microcracks) along with localized macrocrack, and the crack width development rate along the beam height is smaller than that of normal concrete since steel fibers and steel reinforcement bars are supposed to be effective in controlling crack width propagation of the UHPC beam. However, an effective crack width prediction formula is still underdeveloped for steel reinforced UHPC beam. The present study aims to formulate a crack width prediction equation based on the equations in Chinese code GB50010 where the parameters can be regressed and calibrated. Ten UHPC beams with different steel fiber volumes and reinforcing ratios are experimentally tested to collect crack width and spacing data for comparison and validation purposes. Nonuniformity distribution coefficient of rebar strain and average crack spacing are calibrated by the test data. Also, rebar stress is calculated with considering residual tensile strength of UHPC based on a sectional analysis. The modified crack width equation is validated with the test results, showing the best prediction accuracy of 0.97 and standard deviation of 0.11 for the test beams in this study compared to those predicted by JTG 3362, CECS 38, MC and AFGC. This study is emphasizing crack width prediction and control in designing UHPC structures.

Flexural properties of low-height prestressed T-beams: tests and numerical simulations

PurposeThis paper presents the experimental and numerical results of the bending properties of low-height prestressed T-beams. The purpose is to study the bearing capacity, failure state and strain distribution of low-height prestressed T-beams.Design/methodology/approachFirst, two 13 m-long full-size test beams were fabricated with different positions of prestressed steel bundles in the span. The load–deflection curves and failure patterns of each test beam were obtained through static load tests. Secondly, the test data were used to validate the finite element model developed to simulate the flexural behavior of low-height prestressed T-beams. Finally, the influence of different parameters (the number of prestressed steel bundles, initial prestress and concrete strength grade) on the flexural performance of the test beams is studied by using a finite element model.FindingsThe test results show that when the distance of the prestressed steel beam from the bottom height of the test beam increases from 40 to 120 mm, the cracking load of the test beam decreases from 550.00 to 450.00 kN, reducing by 18.18%, and the ultimate load decreases from 1338.15 to 1227.66 kN, reducing by 8.26%, therefore, the increase of the height of the prestressed steel beam reduces the bearing capacity of the test beam. The numerical simulation results show that when the number of steel bundles increases from 2 to 9, the cracking load increases by 183.60%, the yield load increases by 117.71% and the ultimate load increases by 132.95%. Therefore, the increase in the number of prestressed steel bundles can increase the cracking load, yield load and ultimate load of the test beam. When the initial prestress is from 695 to 1,395 MPa, the cracking load increases by 69.20%, the yield load of the bottom reinforcement increases by 31.61% and the ultimate load increases by 3.97%. Therefore, increasing the initial prestress can increase the cracking load and yield load of the test beam, but it has little effect on the ultimate load. The strength grade of concrete increases from C30 to C80, the cracking load is about 455.00 kN, the yield load is about 850.00 kN and the ultimate load is increased by 4.90%. Therefore, the improvement in concrete strength grade has little influence on the bearing capacity of the test beam.Originality/valueBased on the experimental study, the bearing capacity of low-height prestressed T-beams with different prestressed steel beam heights is calculated by finite element simulation, and the influence of different parameters on the bearing capacity is discussed. This method not only ensures the accuracy of bearing capacity assessment, but also does not require a large number of samples and has a certain economy. The study of prestressed low-height T-beams is of great significance for understanding the principle and application of prestressed technology. Research on the mechanical behavior and performance of low-height prestressed T beams can provide a scientific basis and technical support for the design and construction of prestressed concrete structures. In addition, the study of prestressed low-height T-beams can also provide a reference for the optimization design and construction of other structural types.