Rehydration of ultra-high performance concrete matrix incorporating metakaolin under long-term water curing

2021 ◽  
Vol 306 ◽  
pp. 124875
Author(s):  
Zongyun Mo ◽  
Hua Zhao ◽  
Li Jiang ◽  
Xintong Jiang ◽  
Xiaojian Gao
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Ultra High Performance Concrete ◽  
Water Curing ◽  
Concrete Matrix

Volumetric Changes of the UHPC Matrix and its Determination

2016 ◽  
Vol 827 ◽  
pp. 215-218 ◽  
Author(s):  
David Čítek ◽  
Milan Rydval ◽  
Jiří Kolísko
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
Experimental Tests ◽  
Structure Design ◽  
Ultra High Performance Concrete ◽  
Fine Grained ◽  
Durability Properties ◽  
Shrinkage And Creep

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.

Development on the Corrosion of Steel Fiber and Prevention in the Ultra-High Performance Concrete (UHPC)

2021 ◽  
Vol 1036 ◽  
pp. 358-370
Author(s):  
Zhen Wen Guo ◽  
Xin Zhi Duan ◽  
Qiang Wang ◽  
Si Jia Wang ◽  
Xiao Lu Guo
Keyword(s):  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Chloride Ions ◽  
Control Methods ◽  
Ultra High Performance Concrete ◽  
Hybrid Fibers ◽  
Steel Bar ◽  
Corrosion Of Steel

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.

scholarly journals Utilizing Iron Ore Tailing as Cementitious Material for Eco-Friendly Design of Ultra-High Performance Concrete (UHPC)

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1829
Author(s):  
Gang Ling ◽  
Zhonghe Shui ◽  
Xu Gao ◽  
Tao Sun ◽  
Rui Yu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Carbon Emission ◽  
Iron Ore ◽  
High Performance Concrete ◽  
Cementitious Material ◽  
Early Age ◽  
Ultra High Performance Concrete ◽  
Iron Ore Tailing

In this research, iron ore tailing (IOT) is utilized as the cementitious material to develop an eco-friendly ultra-high performance concrete (UHPC). The UHPC mix is obtained according to the modified Andreasen and Andersen (MAA) packing model, and the applied dosage of IOT is 10%, 20%, and 30% (by weight), respectively. The calculated packing density of different mixtures is consistent with each other. Afterwards, the fresh and hardened performance of UHPC mixtures with IOT are evaluated. The results demonstrate that the workability of designed UHPC mixtures is increased with the incorporation of IOT. The heat flow at an early age of designed UHPC with IOT is attenuated, the compressive strength and auto shrinkage at an early age are consequently reduced. The addition of IOT promotes the development of long-term compressive strength and optimization of the pore structure, thus the durability of designed UHPC is still guaranteed. In addition, the ecological estimate results show that the utilization of IOT for the UHPC design can reduce the carbon emission significantly.

Experimental Verification of Pre-Stressed Beams

2014 ◽  
Vol 1054 ◽  
pp. 116-121
Author(s):  
Jan Tichý ◽  
Renata Cvancigerová
Keyword(s):  
Czech Republic ◽  
High Performance ◽  
Applied Research ◽  
High Performance Concrete ◽  
Specific Production ◽  
Ultra High Performance Concrete ◽  
The Czech Republic ◽  
Manufacturing Facility

The paper is a follow-up to previous presentations regarding the experience with ultra-high-performance (UHPC) concrete in the Czech Republic. It will present specific production and testing of pre-stressed beams in the company Skanska a.s. In 2013, the manufacturing facility of the company Skanska a.s. in Štětí, the Prefa plant, produced several series of pre-stressed beams made of ultra-high-performance concrete. The last series of pre-stressed beams was kept in a storage facility in Štětí over winter. In February 2014, destructive tests were carried out on two of the beams in the Štětí facility directly. Another two beams are used for monitoring the long-term changes under continuous load. A description of the tests and their results will be published in the paper. At the same time, a number of accompanying tests were carried out in the Klokner Institute of ČVUT in Prague. The results of these tests will also be mentioned in this paper. The experience and results have been achieved thanks to the grant project no. TA01010269 “Applied research of ultra-high-performance concrete (UHPC) for precast units of structures” subsidized by the Technology Agency of the Czech Republic.

Design of an Experimental Arch Pedestrian Bridge Made of UHPC

2016 ◽  
Author(s):  
Petr Tej ◽  
Petr Kněž ◽  
Jan Mourek
Keyword(s):  
Shell Structure ◽  
High Performance ◽  
High Performance Concrete ◽  
Total Width ◽  
Bridge Structure ◽  
Ultra High Performance Concrete ◽  
Pedestrian Bridge ◽  
Computer Analyses ◽  
Term Monitoring

This paper presents the design of an experimental arch pedestrian bridge made of ultra-high performance concrete (UHPC). The structure is designed as a permanent single-span bridge. The span of the bridge structure is 10.00 m, the total width of shell structure is 0.03 m, and the clearance width of the bridge is 1.50 m. The main structure of the bridge is one prefabricated arch shell structure made of UHPC with dispersed steel fibers without conventional reinforcement. Simultaneously with the designing of the bridge, computer analyses were created in which optimization of the material and geometric parameters of the structure were carried out. The presentation on the conference will contain also production and assembly of the pedestrian bridge. The presentation will include also long-term monitoring of the specimen of the shell structure in 1:1 scale and finally experimentally obtained load bearing capacity of the specimen. Production and testing of the bridge is scheduled for July 2016.

UHPC: a Durable Concrete Overlay Solution for Bridge Decks

2019 ◽  
Author(s):  
Gregory Nault ◽  
Eric Samson
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Ultra High Performance Concrete ◽  
Crack Control ◽  
Concrete Deterioration ◽  
Load Carrying ◽  
Strengthening Technique ◽  
Existing Bridges ◽  
Strength And Durability

<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>

Summary of the test results of short-term and long-term loading of prestressed I-beams made of ultra-high performance concrete

2015 ◽  
Vol 105 (15) ◽  
pp. 1-7
Author(s):  
Petr Tej ◽  
Jiří Kolísko ◽  
Petr Bouška ◽  
Miroslav Vokáč ◽  
Jindřich Čech
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Test Results ◽  
Ultra High Performance Concrete ◽  
Short Term
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