UHPC: a Durable Concrete Overlay Solution for Bridge Decks

Author(s):  
Gregory Nault ◽  
Eric Samson

<p>The key to designing and constructing longer-lasting bridges is through the use of more durable materials. Ultra-high performance concrete (UHPC) is an emerging technology used in bridge infrastructure projects across North America, Europe, and Asia. UHPC is an engineered cementitious fiber-reinforced composite with exceptional strength and durability due to its densely packed matrix, discontinuous pore structure, and micro- crack control. These characteristics significantly delay typical concrete deterioration mechanisms in UHPC. For this reason, bridge specifiers are more frequently including UHPC into their designs. One application of particular interest is the use of UHPC as a thin-bonded, structurally-composite overlay at the surface of the bridge deck. This topping layer provides a riding surface that is both abrasion resistant and virtually impermeable and will protect the conventional materials and elements underneath. Additionally, this layer can be used as a strengthening technique to increase the live load carrying capacity of the existing structure. This solution is being deployed on both new and existing bridges as a rehabilitation strategy and to provide long-term protection to the deck.</p>

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sarmad Shafeeq Abdulqader ◽  
Asmaa Ali Ahmed ◽  
Nawfal Shihab Ahmed

Abstract Concrete Technology has been developing for more than a century. One of the most exceptional achievements in concrete technology is the evolving of Ultra-High Performance Concrete (UHPC) which has been a research focus in a wide applications diversity. In this paper, an experimental work has been carried out for investigating the transverse and longitudinal reinforcements’ variation influence on the axial capacity of UHPC columns. Eight columns (five UHPC columns and three Normal Strength Concrete (NSC) columns) have been poured and tested under a concentric axial compression load till a failure is reached. Then, the results are reported herein. The experimental results show that UHPC columns failed in a controlled manner and no concrete chips or a concrete cover spalling are observed. Also, the longitudinal reinforcements have not buckled away beyond the peak load because of the presence of the reinforcing steel fibers in UHPC. Correspondingly, the steel ties spacing proportionally affects the load carrying capacity of columns as presented hereinafter.


2016 ◽  
Vol 827 ◽  
pp. 215-218 ◽  
Author(s):  
David Čítek ◽  
Milan Rydval ◽  
Jiří Kolísko

Research in the Ultra-High Performance Concrete applications field is very important. Current experiences shows that the structure design should be optimize due to relatively new fine-grained cement-based Hi-Tech material with excellent mechanical and durability properties. It is not sure if some of the volumetric changes like creep or shrinkage has or has not an impact on an advantage for the construction and for the structure design. The effect of the shrinkage and creep of common used concretes are well known and well described at publications but the effect of volumetric changes of the UHPC is mostly unknown because of the fact that some of experimental tests are long term and the development of UHPC is still in its basics. A lot of works are focused on a basic mechanical properties and durability tests.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6944
Author(s):  
Julio A. Paredes ◽  
Jaime C. Gálvez ◽  
Alejandro Enfedaque ◽  
Marcos G. Alberti

This paper seeks to optimize the mechanical and durability properties of ultra-high performance concrete (UHPC). To meet this objective, concrete specimens were manufactured by using 1100 kg/m3 of binder, water/binder ratio 0.20, silica sand and last generation of superplasticizer. Silica fume, metakaolin and two types of nano silica were used for improving the performances of the concrete. Additional mixtures included 13 mm long OL steel fibers. Compressive strength, electrical resistivity, mercury intrusion porosimetry tests, and differential and thermogravimetric thermal analysis were carried out. The binary combination of nano silica and metakaolin, and the ternary combination of nano silica with metakaolin and silica fume, led to the best performances of the UHPC, both mechanical and durable performances.


Author(s):  
Wee Teo ◽  
Kazutaka Shirai ◽  
Yin Hor

<p>Two test series with various UHPC strengthening interventions were conducted in this study to investigate the behaviour of composite reinforced concrete (RC) slabs strengthened with UHPC. The first, RE series is a retrofit interventions, tested UHPC as patch material for repairing deteriorated concrete structures. As for the second, OV series is a UHPC overlay interventions, was used to strengthen soffit of RC slab members. The results showed that, in RE series, UHPC safeguard against diagonal cracking compare to conventional RC slab. The UHPC exhibited excellent energy absorption with extensive deflection hardening and ductility during the post cracking range. In OV series, all slabs showed formation of diagonal shear cracks and sign of debonding modes. The UHPC overlay delayed the development of shear cracking. The ultimate load carrying capacity and tendency of flexural failure increase with the overlay thickness.</p>


Author(s):  
Julio Paredes ◽  
Jaime C. Gálvez ◽  
Alejandro Enfedaque ◽  
Marcos G. Alberti

This paper seeks to optimize the mechanical and durability properties of ultra-high performance concrete (UHPC). To meet this objective, concrete specimens were manufactured by using 1,100 kg/m3 of binder, water/binder ratio 0.20, silica sand and last generation of superplasticizer. Silica fume, metakaolin and two types of nano silica were used for improving the performances of the concrete. Additional mixtures included 13mm long OL steel fibers. Compressive strength, electrical resistivity, mercury intrusion porosimetry tests and differential and thermogravimetric thermal analysis were carried out. The binary combination of nano silica and metakaolin, and the ternary combination of nano silica with metakaolin and silica fume, led to the best performances of the UHPC, both mechanical and durable performances.


2021 ◽  
Vol 1036 ◽  
pp. 358-370
Author(s):  
Zhen Wen Guo ◽  
Xin Zhi Duan ◽  
Qiang Wang ◽  
Si Jia Wang ◽  
Xiao Lu Guo

Chloride ions, water, and oxygen could cause the corrosion of steel fiber in the aggressive environment. The corrosion of steel fiber in UHPC is a long-term process and the rate is very slow. As one of the important components of ultra-high performance concrete (UHPC), the corrosion of steel fiber is the result of multiple factors. The characteristics of steel fiber corrosion in UHPC, the factors influencing the corrosion of steel fiber in UHPC (including nanomaterials, curing condition and crack width), and effects of steel fiber corrosion on the UHPC performance (including mechanical properties, matrix rehydration and corrosion of steel bar), are emphatically elaborated. And the control methods of steel fiber corrosion in UHPC are briefly introduced, i.e. hybrid fibers and stainless steel fibers.


2008 ◽  
Vol 400-402 ◽  
pp. 385-390 ◽  
Author(s):  
Jian Yang ◽  
Zhi Fang

An experimental program was formulated to investigate the characteristics of complete stress-strain curve of UHPC in uniaxial compression and flexural behaviors of prestressed UHPC beams. The particular focus was the influence of the partial prestress ratio and jacking stress on the flexural response of UHPC beams. The tests of beams demonstrated that the UHPC beams have an excellent behavior in load carrying capacity, crack distribution and deformability; their ultimate deflection can reach 1/34~1/42 of the span. Based on this investigation, theoretical correlations for the prediction structure response of UHPC beams are proposed.


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