Material Properties of Ultra - High Performance Concrete in Extreme Conditions

2016 ◽  
Vol 711 ◽  
pp. 157-162 ◽  
Author(s):  
David Citek ◽  
Milan Rydval ◽  
Stanislav Rehacek ◽  
Jiří Kolísko
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Material Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Accurate Information ◽  
Extreme Conditions ◽  
Ultra High Performance Concrete ◽  
Freeze Thaw

The Ultra High Performance Concrete (UHPC) is a very promising material suitable for application in special structures. However, the knowledge of performance of this relatively new material is rather limited. The exceptional mechanical properties of UHPC allow for a modification of the design rules, which are applicable in ordinary or high strength concrete. This paper deals in more detail with impact of thermal stress on bond properties between prestressing strands and UHPC and an influence of high temperature to final material properties of different UHPC mixtures. Specimens in the first experimental part were subjected to the cycling freeze-thaw testing. The relationship between bond behavior of both type of material (UHPC and ordinary concrete) and effect of cycling freeze-thaw tests was investigated. The second part of experimental work was focused on mechanical properties of UHPC exposure to the high temperature (Tmax = 200°C to Tmax = 1000°C). Tested mechanical properties were compressive and flexural strengths, the fracture properties will be presented in the next paper. The obtained experimental data serve as a basis for further systematic experimental verification and more accurate information about the significantly higher material properties of UHP(FR)C and its behavior in extreme conditions.

Factorial Design Approach of Ultra-High Performance Concrete

2013 ◽  
Vol 405-408 ◽  
pp. 2847-2850
Author(s):  
Wu Jian Long ◽  
Wei Lun Wang ◽  
Qi Ling Luo ◽  
Bi Qin Dong
Keyword(s):  
Mechanical Properties ◽  
Factorial Design ◽  
Statistical Models ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Design Approach ◽  
Ultra High Performance Concrete ◽  
Self Consolidating Concrete ◽  
Slump Flow

In order to understand the influence of mixture parameters on ultra-high strength self-consolidating concrete (UHS-SCC) behaviour, an experimental design was carried out in this investigation. In total, 19 SCC mixtures were prepared to determine several key responses that affect the slump flow and compressive strength of UHS-SCC. The statistical models derived from the factorial design approach can be used to quantify the effect of mixture parameters and their coupled effects on fresh and mechanical properties of SCC.

scholarly journals State of the Art: Mechanical Properties of Ultra-High Performance Concrete

2017 ◽  
Vol 3 (3) ◽  
pp. 190-198 ◽  
Author(s):  
Mohamadtaqi Baqersad ◽  
Ehsan Amir Sayyafi ◽  
Hamid Mortazavi Bak
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
State Of The Art ◽  
High Strength ◽  
Structural Members ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
The Past ◽  
Very High

During the past decades, there has been an extensive attention in using Ultra-High Performance Concrete (UHPC) in the buildings and infrastructures construction. Due to that, defining comprehensive mechanical properties of UHPC required to design structural members is worthwhile. The main difference of UHPC with the conventional concrete is the very high strength of UHPC, resulting designing elements with less weight and smaller sizes.  However, there have been no globally accepted UHPC properties to be implemented in the designing process. Therefore, in the current study, the UHPC mechanical properties such as compressive and tensile strength, modulus of elasticity and development length for designing purposes are provided based on the reviewed literature. According to that, the best-recommended properties of UHPC that can be used in designing of UHPC members are summarized. Finally, different topics for future works and researches on UHPC’s mechanical properties are suggested.

scholarly journals Meta-Analysis of Fiber Impact on Mechanical Properties of Ultra-High Performance Concrete

2020 ◽  
Author(s):  
Faiq M. Al-Zwainy ◽  
Hussam k. Risan ◽  
Rana I. K. Zaki
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Meta Analysis ◽  
High Strength ◽  
Ultimate Compressive Strength ◽  
Ultra High Performance Concrete

The purpose of this study was to conduct a meta-analysis that shows the influence of fiber on ultimate compressive strength and tensile strength of ultra-high performance concrete. The internet scholarly search engines and ScienceDirect article references were used to illustrate the papers concerning the experimental investigations of mechanical properties of ultra-high strength concrete with and without fiber with clearly, completely and comparative raw data. The normal concrete test results were dismissed from this search. Seven trials were identified based on the adopted inclusion and exclusion criteria above. The meta-analysis based on standardized mean difference was carried out on the basis of a fixed-effects model for the major outcomes of the ultimate compressive and tensile properties of ultra-high performance concrete. A total of 888 test specimens were enrolled in these seven trials. The combined analysis yielded a sign of a significant improvement in ultimate compressive strength and tensile strength of ultra-high strength concrete with fiber addition of 2% by concrete volume. The summary effect size of ultimate compressive strength was 2.34 while a more improvement in term of tensile strength with effect size of 2.64. By addition fiber of 2% provides a significant benefit in mechanical properties of ultra-high performance concrete.

Fire-Damage or Freeze-Thaw of Strengthening Concrete Using Ultra High Performance Concrete

2009 ◽  
Vol 79-82 ◽  
pp. 2047-2050 ◽  
Author(s):  
Min Gin Lee ◽  
Yi Shuo Huang
Keyword(s):  
High Temperature ◽  
High Performance ◽  
High Performance Concrete ◽  
Fire Damage ◽  
Ultra High Performance Concrete ◽  
Freeze Thaw ◽  
Concrete Members ◽  
Repair Materials ◽  
Environmental Durability ◽  
Temperature Exposure

There are some reinforced concrete structures exposed to severe environmental conditions might require maintenance or strengthening. Many of these severe circumstances are the result of extreme climate conditions such as low temperature, freeze–thaw action, fire attack, and exposure to deicing salts. Because of this, the environmental durability of both the repair materials and methods used in rehabilitation applications are of utmost importance. A small fire can reach 250°C, while a common blaze can easily produce temperatures of around 800°C. In major conflagrations the temperature can even reach 1100°C. At this level, the heat affects most materials, provoking the spontaneous combustion of some of them and affecting the resistance of others. However, very little research has been performed in evaluating the environmental durability of strengthening materials for concrete members. Very little work has been done on the effects of freeze–thaw cycling on bonding and repair materials. In this study, ultra high performance concrete (UHPC) was used to investigate the effect of strengthening concrete members by fire-damage test or freeze-thaw test. The results show that the mechanical properties of UHPC possess high strength, toughness, and freeze-thaw resistance. The CFRP (carbon fiber reinforced plates) wrapping specimens exposed at 300 °C showed totally failure with the deterioration of the adhesive. The UHPC with bonding 10 mm thickness specimens exposed at 400 °C and duration of 1 hour still in good shape. The UHPC with 1-cm or 2-cm thickness on strengthening concrete members could be obtained specific retrofit effects. The performance of UHPC specimens is better than those of CFRP wrapping specimens during high temperature exposure. The results of slant shear tests show that the bond strength of PC/PC, UHPC/PC and UHPC/UHPC decreased significantly after 600 freeze–thaw cycles or high temperature exposure.

Ultra-high performance concrete – properties and technology

2013 ◽  
Vol 61 (1) ◽  
pp. 183-193 ◽  
Author(s):  
T. Zdeb
Keyword(s):  
Mechanical Properties ◽  
Hydrothermal Treatment ◽  
High Performance ◽  
High Performance Concrete ◽  
Qualitative Evaluation ◽  
High Strength ◽  
Ultra High Performance Concrete ◽  
Characteristic Features ◽  
Reactive Powder ◽  
New Generation

Abstract The paper deals with information concerning properties and technology of a new generation cementitious composite i.e. Ultra-High Performance Concrete. High performance here means both high strength and high durability under the influence of environmental factors. This group of composites is mainly represented by Reactive Powder Concretes (RPC), which show both outstanding durability and mechanical properties. Characteristic features of RPC are mainly due to the very low water-cement ratio, which involves application of superplasticizer, significant reduction of aggregate grains size as well as hydrothermal treatment. In the first part of the paper selected properties of RPC are compared to ordinary concrete and to other groups of new generation concrete. Moreover, fundamental technological factors influencing properties of RPC are described as well. The second part deals with the RPC developed at Cracow University of Technology. The presented test results are mainly focused on the influence of steel fibres content on mechanical properties of reactive powder concrete and hydrothermal treatment on composites microstructure. The quantitative and qualitative evaluation of this relationship expand the knowledge of the UHPC technology. Finally, the third part presents the most significant and newest structures which have been erected with the use of RPC

scholarly journals Hugoniot Data and Equation of State Parameters for an Ultra-High Performance Concrete

2021 ◽  
Author(s):  
C. Sauer ◽  
F. Bagusat ◽  
M.-L. Ruiz-Ripoll ◽  
C. Roller ◽  
M. Sauer ◽  
...  
Keyword(s):  
Equation Of State ◽  
High Performance ◽  
High Performance Concrete ◽  
Applied Pressure ◽  
High Strength ◽  
Parameter Study ◽  
Ultra High Performance Concrete ◽  
Data Set ◽  
Shock Response ◽  
Particle Velocities

AbstractThis work aims at the characterization of a modern concrete material. For this purpose, we perform two experimental series of inverse planar plate impact (PPI) tests with the ultra-high performance concrete B4Q, using two different witness plate materials. Hugoniot data in the range of particle velocities from 180 to 840 m/s and stresses from 1.1 to 7.5 GPa is derived from both series. Within the experimental accuracy, they can be seen as one consistent data set. Moreover, we conduct corresponding numerical simulations and find a reasonably good agreement between simulated and experimentally obtained curves. From the simulated curves, we derive numerical Hugoniot results that serve as a homogenized, mean shock response of B4Q and add further consistency to the data set. Additionally, the comparison of simulated and experimentally determined results allows us to identify experimental outliers. Furthermore, we perform a parameter study which shows that a significant influence of the applied pressure dependent strength model on the derived equation of state (EOS) parameters is unlikely. In order to compare the current results to our own partially reevaluated previous work and selected recent results from literature, we use simulations to numerically extrapolate the Hugoniot results. Considering their inhomogeneous nature, a consistent picture emerges for the shock response of the discussed concrete and high-strength mortar materials. Hugoniot results from this and earlier work are presented for further comparisons. In addition, a full parameter set for B4Q, including validated EOS parameters, is provided for the application in simulations of impact and blast scenarios.

scholarly journals Abrasion Resistance of Ultra-High-Performance Concrete for Railway Sleepers

2021 ◽  
Author(s):  
Ariful Hasnat ◽  
Nader Ghafoori
Keyword(s):  
Prestressed Concrete ◽  
Abrasion Resistance ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Positive Influence ◽  
Cementitious Material ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Ultra High Performance Concrete

AbstractThis study aimed to determine the abrasion resistance of ultra-high-performance concretes (UHPCs) for railway sleepers. Test samples were made with different cementitious material combinations and varying steel fiber contents and shapes, using conventional fine aggregate. A total of 25 UHPCs and two high-strength concretes (HSCs) were selected to evaluate their depth of wear and bulk properties. The results of the coefficient of variation (CV), relative gain in abrasion, and abrasion index of the studied UHPCs were also obtained and discussed. Furthermore, a comparison was made on the resistance to wear of the selected UHPCs with those of the HSCs typically used for prestressed concrete sleepers. The outcomes of this study revealed that UHPCs displayed excellent resistance against abrasion, well above that of HSCs. Amongst the utilized cementitious material combinations, UHPCs made with silica fume as a partial replacement of cement performed best against abrasion, whereas mixtures containing fly ash showed the highest depth of wear. The addition of steel fibers had a more positive influence on the abrasion resistance than it did on compressive strength of the studied UHPCs.

scholarly journals The Mechanical Properties and Damage Evolution of UHPC Reinforced with Glass Fibers and High-Performance Polypropylene Fibers

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2455
Author(s):  
Jiayuan He ◽  
Weizhen Chen ◽  
Boshan Zhang ◽  
Jiangjiang Yu ◽  
Hang Liu
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Damage Evolution ◽  
High Performance ◽  
High Performance Concrete ◽  
Glass Fibers ◽  
Ultra High Performance Concrete ◽  
Concrete Damaged Plasticity ◽  
The Difference ◽  
Experimental Values

Due to the sharp and corrosion-prone features of steel fibers, there is a demand for ultra-high-performance concrete (UHPC) reinforced with nonmetallic fibers. In this paper, glass fiber (GF) and the high-performance polypropylene (HPP) fiber were selected to prepare UHPC, and the effects of different fibers on the compressive, tensile and bending properties of UHPC were investigated, experimentally and numerically. Then, the damage evolution of UHPC was further studied numerically, adopting the concrete damaged plasticity (CDP) model. The difference between the simulation values and experimental values was within 5.0%, verifying the reliability of the numerical model. The results indicate that 2.0% fiber content in UHPC provides better mechanical properties. In addition, the glass fiber was more significant in strengthening the effect. Compared with HPP-UHPC, the compressive, tensile and flexural strength of GF-UHPC increased by about 20%, 30% and 40%, respectively. However, the flexural toughness indexes I5, I10 and I20 of HPP-UHPC were about 1.2, 2.0 and 3.8 times those of GF-UHPC, respectively, showing that the toughening effect of the HPP fiber is better.

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