Behavior of ultra-high-performance concrete columns subjected to axial compressive load

2021 ◽  
pp. 136943322110384
Author(s):  
Kaize Ma ◽  
Yudong Ma ◽  
Guohua Xing ◽  
Boquan Liu
Keyword(s):  
Constitutive Model ◽  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Compressive Load ◽  
Ultra High Performance Concrete ◽  
Fiber Volume ◽  
Element Analysis ◽  
Plastic Damage ◽  
Load Displacement

A constitutive model of confined ultra-high-performance concrete (UHPC) was developed based on the theoretical and regression analyses. This constitutive model could be applied to finite element analysis (FEA) according to the comparison of plastic damage analysis and load–displacement curves. A total of 25 stirrup-confined UHPC columns were created through FEA modeling. The variables included stirrup spacing, stirrup configuration, steel fiber volume, and longitudinal reinforcement ratio. The load–displacement curves and the plastic damage region of the UHPC columns were illustrated and analyzed. Moreover, parametric analysis was conducted to evaluate the effects of the aforementioned parameters. The improvement in the bearing capacity and ductility of the UHPC columns resulting from the reduction in stirrup spacing and increase in steel fiber volume indicated that the columns were significantly influenced by the stirrup spacing, stirrup configuration, and steel fiber volume.

scholarly journals Ultra high performance concrete shear walls

2021 ◽  
Vol 294 ◽  
pp. 04004
Author(s):  
YiChen Fang
Keyword(s):  
Finite Element ◽  
High Performance ◽  
High Performance Concrete ◽  
Shear Walls ◽  
Element Model ◽  
Current Status ◽  
Ultra High Performance Concrete ◽  
Element Analysis ◽  
Shear Bearing Capacity ◽  
Load Displacement

The history of the development of Ultra-High Performance Concrete (UHPC) shear walls and the current status of today’s research as well as the future development prospects are comprehensively collated. The analysis process and conclusive results of the present-day domestic and international research on UHPC shear walls are highlighted. The load displacement curves, hysteresis curves and skeleton lines of ultra-high performance concrete shear walls under different experimental loads are collated and compared. Integrate the corresponding equations for shear bearing capacity and equations for the overall specimen load displacement curves. A finite element model of the ultra-high performance concrete shear wall is established to simulate and perform non-linear finite element analysis of its force process under unidirectional horizontal loading.

scholarly journals Experimental Study on Shear Performance of Cast-In-Place Ultra-High Performance Concrete Structures

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3254 ◽  
Author(s):  
Li ◽  
Feng ◽  
Ke ◽  
Pan ◽  
Nie
Keyword(s):  
Shear Strength ◽  
High Performance ◽  
Fiber Volume Fraction ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Steel Fibers ◽  
Direct Shear ◽  
Ultra High Performance Concrete ◽  
Fiber Volume

In order to study the direct shear properties of ultra-high performance concrete (UHPC) structures, 15 Z-shaped monolithic placement specimens (MPSs) and 12 Z-shaped waterjet treated specimens (WJTSs) were tested to study the shear behavior and failure modes. The effects of steel fiber shape, steel fiber volume fraction and interface treatment on the direct shear properties of UHPC were investigated. The test results demonstrate that the MPSs were reinforced with steel fibers and underwent ductile failure. The ultimate load of the MPS is about 166.9% of the initial cracking load. However, the WJTSs failed in a typical brittle mode. Increasing the fiber volume fraction significantly improves the shear strength, which can reach 24.72 MPa. The steel fiber type has little effect on the shear strength and ductility, while increasing the length of steel fibers improves its ductility and slightly reduces the shear strength. The direct shear strength of the WJTSs made from 16 mm hooked-type steel fibers can reach 9.15 MPa, which is 2.47 times the direct shear strength of the specimens without fibers. Finally, an interaction formula for the shear and compressive strength was proposed on the basis of the experimental results, to predict the shear load-carrying capacity of the cast-in-place UHPC structures.

scholarly journals Influence of Fiber Volume Fraction and Fiber Orientation on the Uniaxial Tensile Behavior of Rebar-Reinforced Ultra-High Performance Concrete

Fibers ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 67 ◽  
Author(s):  
Manish Roy ◽  
Corey Hollmann ◽  
Kay Wille
Keyword(s):  
Fiber Orientation ◽  
High Performance ◽  
Fiber Volume Fraction ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Tensile Behavior ◽  
Uniaxial Tensile ◽  
Ultra High Performance Concrete ◽  
Load Direction ◽  
Fiber Volume

This paper studied the influence of fiber volume fraction ( V f ), fiber orientation, and type of reinforcement bar (rebar) on the uniaxial tensile behavior of rebar-reinforced strain-hardening ultra-high performance concrete (UHPC). It was observed that the tensile strength increased with the increase in V f . When V f was kept constant at 1%, rebar-reinforced UHPC with fibers aligned with the load direction registered the highest strength and that with fibers oriented perpendicular to the load direction recorded the lowest strength. The strength of the composite with random fibers laid in between. Moreover, the strength, as well as the ductility, increased when the normal strength grade 60 rebars embedded in UHPC were replaced with high strength grade 100 rebars with all other conditions remaining unchanged. In addition, this paper discusses the potential of sudden failure of rebar-reinforced strain hardening UHPC and it is suggested that the composite attains a minimum strain of 1% at the peak stress to enable the members to have sufficient ductility.

scholarly journals Flexural Strength Evaluation of Reinforced Concrete Members with Ultra High Performance Concrete

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Baek-Il Bae ◽  
Hyun-Ki Choi ◽  
Chang-Sik Choi
Keyword(s):  
Flexural Strength ◽  
High Performance ◽  
Strain Softening ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
High Strength ◽  
Tension Stress ◽  
Compression Stress ◽  
Ultra High Performance Concrete ◽  
Stress Block

Flexural strength evaluation models for steel fiber reinforced ultra high strength concrete were suggested and evaluated with test results. Suggested flexural strength models were composed of compression stress blocks and tension stress blocks. Rectangular stress block, triangular stress block, and real distribution shape of stress were used on compression side. Under tension, rectangular stress block distributed to whole area of tension side and partial area of tension side was used. The last model for tension side is realistic stress distribution. All these models were verified with test result which was carried out in this study. Test was conducted by four-point loading with 2,000 kN actuator for slender beam specimen. Additional verifications were carried out with previous researches on flexural strength of steel fiber reinforced concrete or ultra high strength concrete. Total of 21 test specimens were evaluated. As a result of comparison for flexural strength of section, neutral axis depth at ultimate state, models with triangular compression stress block, and strain-softening type tension stress block can be used as exact solution for ultra high performance concrete. For the conservative and convenient design of section, modified rectangular stress block model can be used with strain softening type tension stress block.

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