Numerical analyses on flexural performance of UHPC link slab- abutment backwall system in jointless bridges

2021 ◽  
Author(s):  
Bruno Briseghella ◽  
Zhen-Guo Yang ◽  
Jun-Qing Xue ◽  
Jian-hui Lin ◽  
Fu-yun Huang
Keyword(s):  
Crack Resistance ◽  
High Performance ◽  
High Performance Concrete ◽  
Element Model ◽  
Bending Stiffness ◽  
Ultra High Performance Concrete ◽  
Rubber Sheet ◽  
Flexural Performance ◽  
Jointless Bridges ◽  
The Finite Element Model

<p>The link slab could be applied to the abutment-superstructure connections to eliminate deck joints to form a link slab-abutment backwall (LS-AB) system in jointless bridges. However, due to the rotation and longitudinal deformation of girder ends, the reinforced concrete LS-AB system may crack. In order to improve the crack resistance of the LS-AB system, the ultra-high performance concrete (UHPC) could be used. The finite element model was built by ABAQUS to investigate the flexural performance of the UHPC LS-AB system. The results indicated that UHPC could improve the ultimate load, bending stiffness and crack resistance of the LS-AB system. The cracks mainly appeared on the link slab under bending. With an increase in the ratio of rubber sheet length to span, the displacement corresponding to initial concrete cracks increase. The bending stiffness of the UHPC LS-AB system is mainly influenced by the material and rubber sheet length.</p>

Evaluation of Flexural Performance in UHPC(Ultra High Performance Concrete) According to Placement Methods

2009 ◽  
Vol 417-418 ◽  
pp. 581-584 ◽  
Author(s):  
Gum Sung Ryu ◽  
Su Tae Kang ◽  
Jung Jun Park ◽  
Gyung Taek Koh
Keyword(s):  
Flexural Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Initial Crack ◽  
Ultra High Performance Concrete ◽  
Remarkable Feature ◽  
Flexural Performance ◽  
Placement Method ◽  
Compaction Properties ◽  
And Diffusion

Apart from its high compressive, tensile and flexural strengths reaching approximately 200MPa, 15MPa and 35MPa, respectively, Ultra High Performance Concrete (UHPC) is characterized by its high resistance against degrading factors that can delay their penetration and diffusion speeds down to 1/20 to maximum 1/10,000 compared to ordinary concrete. UHPC also exhibits self-compaction properties with a slump flow of about 220mm. Furthermore, the most remarkable feature of UHPC is the improvement of its flexural strength and toughness through the admixing of steel fiber. Accordingly, this study evaluates the effects of the placement method on the flexural performance of UHPC. As a result, the flexural strength of UHPC appears to be extremely dependent on the placement method with variation of the maximum flexural strength up to 2 to 3 times while poor influence is observed on the initial crack strength.

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.

Numerical analyses on flexural performance of prefabricated UHPC link slab

2021 ◽  
Author(s):  
Bruno Briseghella ◽  
Wei Xu ◽  
Jun-Qing Xue ◽  
Jian-hui Lin ◽  
Camillo Nuti
Keyword(s):  
Crack Resistance ◽  
Bearing Capacity ◽  
High Performance ◽  
High Performance Concrete ◽  
Labor Cost ◽  
Ultimate Bearing Capacity ◽  
Ultra High Performance Concrete ◽  
Steam Curing ◽  
Expansion Joints

<p><br clear="none"/></p><p>The expansion joints in the multi-span simply supported bridge can be eliminated by using the link slab. The ultra-high performance concrete (UHPC) with high tensile strength and crack resistance is an effective material for the link slab. However, the cast-in-situ UHPC link slab need to be cured with steam curing. Therefore, the construction processes are complicated and the construction quality is difficult to guarantee. In this paper, the prefabricated UHPC link slab which can be assembled on site to simply the construction process, accelerate the construction speed and reduce the labor cost was proposed. Finite element models of the prefabricated and cast-in-situ UHPC link slabs under bending were built by using ABAQUS. The ultimate bearing capacity of the prefabricated link slab was nearly the same of the cast in situ and the crack resistance slightly lower. Finally, the influence of the bolt (used to connect the prefabricated link slab) number and the distance from the bolt to the edge of the link slab on the crack resistance and ultimate bearing capacity of the prefabricated link slab were obtained.</p>

Flexural Performance of Ultra-High Performance Concrete Ballastless Track Slabs

2016 ◽  
Author(s):  
Weina Meng ◽  
Kamal Henri Khayat
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Superior Performance ◽  
Concrete Slabs ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
Cracking Behavior ◽  
Flexural Performance ◽  
Ballastless Track ◽  
Track Slab

Ballastless track slab offers excellent stability and durability and has been well accepted in high-speed railways worldwide. Rails are typically laid on precast concrete slabs that are subjected to dynamic load transferred from the rails. Cracks can be induced by shrinkage and mechanical loading in concrete, which accelerates the degradation and affects the performance of the track slab. As tens of thousands of miles of ballastless track are constructed, effective and efficient maintenance for the concrete slabs has become an issue. In this paper, ultra-high performance concrete (UHPC) is proposed to fabricate ballastless track slab. UHPC is a superior fiber-reinforced, cementitioius mortar, which has greatly-improved mechanical strengths and durability. A recently-developed UHPC is evaluated in terms of the flowability, durability, shrinkage, and mechanical properties. A functionally-graded slab design is proposed with the consideration of initial material cost. The slab is cast with two layers: a layer of conventional concrete at the bottom, and a layer of UHPC on the top. A three-dimensional finite element model is developed for ballastless track slab whose flexural performance is investigated and compared with that of slab made with conventional concrete. Concrete damage plasticity model is incorporated to consider the post-cracking behavior. The results indicate that the proposed UHPC is promising for fabricating ballastless track slab with superior performance.

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