Application of ultra-high performance concrete for thermal resistance materials

2019 ◽  
Author(s):  
Sung-Gul Hong ◽  
Namhee K. Hong ◽  
In-Young Gu
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Resistance ◽  
High Performance ◽  
High Performance Concrete ◽  
Curing Temperature ◽  
Core Material ◽  
Ultra High Performance Concrete ◽  
External Temperature ◽  
Low Thermal Conductivity

<p>This paper investigates the thermal resistance of ultra-high performance concrete (UHPC) composites using different fillers of low thermal conductivity. The development of new concrete for energy saving facilities is more demanding for climate change threat to human. The use of UHPC composite with expanded polystyrene (EPS) beads as well as different fillers of low thermal conductivity has shown a viable option of architectural sandwich walls of insulation. The optimum fillers of thermal resistance for UHPC are determined by the tradeoff of compressive strength between heat conductivity. Better thermal properties of some UHPC composites make lower compressive strength of UHPC. To evaluate the varying thermal and mechanical characteristics of UHPC composites with the quantity of fillers, the method of volumetric substitution for UHPC was investigated in this paper. The UHPC composite of thermal resistance with comparable compressive strength can be possibly used for concrete blocks to transfer flexural compression force in efficient thermal breaker systems. Test results show that the strength of the concrete is greatly influenced by the curing method and the most important factors affecting the strength of concrete are curing temperature and curing time. Structural UHPC walls of thermal resistance serve as both load transfer and barrier to external temperature. To investigate the mechanical behavior of composite sandwich panels, the panels for the study are fabricated by new concrete as core and face sheets and the influence of the three components – the mechanical properties of the core material, the strength of the face sheet material, and the bond strength adhesive material – was evaluated. The flexural capacity of the specimens UHPC with EPS core showed high strength in a stable linear behavior before core cracking.</p>

scholarly journals Ultra-high-performance concrete with local high unburned carbon fly ash

DYNA ◽  
2021 ◽  
Vol 88 (216) ◽  
pp. 38-47
Author(s):  
Joaquín Abellán García ◽  
Nancy Torres Castellanos ◽  
Jaime Antonio Fernandez Gomez ◽  
Andres Mauricio Nuñez Lopez
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
Unburned Carbon ◽  
High Tech ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
The Cost

Ultra-high-performance concrete (UHPC) is a kind of high-tech cementitious material with superb mechanical and durability properties compared to other types of concrete. However, due to the high content of cement and silica fume used, the cost and environmental impact of UHPC is considerably higher than conventional concrete. For this reason, several efforts around the world have been made to develop UHPC with greener and less expensive local pozzolans. This study aimed to design and produce UHPC using local fly ash available in Colombia. A numerical optimization, based on Design of Experiments (DoE) and multi-objective criteria, was performed to obtain a mixture with the proper flow and highest compressive strength, while simultaneously having the minimum content of cement. The results showed that, despite the low quality of local fly ashes in Colombia, compressive strength values of 150 MPa without any heat treatment can be achieved.

scholarly journals Mechanical Properties and Environmental Evaluation of Ultra-High-Performance Concrete with Aeolian Sand

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3148 ◽  
Author(s):  
Hongyan Chu ◽  
Fengjuan Wang ◽  
Liguo Wang ◽  
Taotao Feng ◽  
Danqian Wang
Keyword(s):  
Compressive Strength ◽  
Environmental Impact ◽  
Young’S Modulus ◽  
High Performance ◽  
High Performance Concrete ◽  
Young's Modulus ◽  
Ultra High Performance Concrete ◽  
Aeolian Sand ◽  
Binder Ratio ◽  
Water Binder Ratio

Ultra-high-performance concrete (UHPC) has received increasing attention in recent years due to its remarkable ductility, durability, and mechanical properties. However, the manufacture of UHPC can cause serious environmental issues. This work addresses the feasibility of using aeolian sand to produce UHPC, and the mix design, environmental impact, and mechanical characterization of UHPC are investigated. We designed the mix proportions of the UHPC according to the modified Andreasen and Andersen particle packing model. We studied the workability, microstructure, porosity, mechanical performance, and environmental impact of UHPC with three different water/binder ratios. The following findings were noted: (1) the compressive strength, flexural strength, and Young’s modulus of the designed UHPC samples were in the ranges of 163.9–207.0 MPa, 18.0–32.2 MPa, and 49.3–58.9 GPa, respectively; (2) the compressive strength, flexural strength, and Young’s modulus of the UHPC increased with a decrease in water/binder ratio and an increase in the steel fibre content; (3) the compressive strength–Young’s modulus correlation of the UHPC could be described by an exponential formula; (4) the environmental impact of UHPC can be improved by decreasing its water/binder ratio. These findings suggest that it is possible to use aeolian sand to manufacture UHPC, and this study promotes the application of aeolian sand for this purpose.

Study on the Compressive Strength and Mixing of Ultra-High Performance Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 825-828
Author(s):  
Su Li Feng ◽  
Peng Zhao
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Properties ◽  
Test Method ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Ultra High Performance Concrete ◽  
Mixture Ratio

The test in order to obtain liquidity, higher intensity ultra-high performance concrete(UHPC), in the course of preparation, high intensity quartz sand to replace the ordinary sand,reasonable mixture ratio control low water-cement ratio,the incorporation of part of the test piece ofsteel fibers, produced eight specimens . In the ordinary molding and the standard conservation 28d thecase, the ultra-high-performance concrete compressive strength of more than 170MPa.Thepreparation of the test method and test results will provide the basis for further study of the law of themechanical properties of ultra high strength properties of concrete.

Mechanical Properties and Durability of Ultra-High Performance Concrete Incorporating Coarse Aggregate

2014 ◽  
Vol 629-630 ◽  
pp. 96-103 ◽  
Author(s):  
Juan Yang ◽  
Gai Fei Peng ◽  
Yu Xin Gao ◽  
Hui Zhang
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Raw Materials ◽  
Autogenous Shrinkage ◽  
Mineral Admixtures ◽  
Ultra High Performance Concrete ◽  
Spalling Failure

Ultra-high performance concrete (UHPC) incorporating coarse aggregate was prepared with common raw materials. Fresh concrete had excellent good workability with slump of 265 mm and slump spread of 673 mm. Compressive strength of UHPC at 56 d reached 150 MPa. However, UHPC exhibited high brittleness in terms of spalling failure which occurred during compression loading.The ratio of splitting tensile strength to compressive strength of about 1/18 and the ratio of flexural strength to compressive strength of about 1/14 at 56 d were also associated with the brittleness of UHPC in this research. Mineral admixtures and fluidity of fresh concrete influenced compressive strength of UHPC significantly. Moreover, UHPC had excellent permeation-related durability but considerable shrinkage. Autogenous shrinkage of UHPC was less than half of free shrinkage, for which the reason is unknown and needs further research.

Behavior of High Performance Concrete Under High Temperature (60-450°C) for Surface Long-Term Storage: Thermo-Hydro-Mechanical Residual Properties

2000 ◽  
Vol 663 ◽  
Author(s):  
C. Gallé ◽  
J. Sercombe ◽  
M. Pin ◽  
G. Arcier ◽  
P. Bouniol
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
High Performance ◽  
High Performance Concrete ◽  
Gas Permeability ◽  
Long Term Storage ◽  
Residual Properties ◽  
Term Storage

ABSTRACTAfter various thermal treatments (up to 450°C), residual thermo-hydro-mechanical (T-H-M) properties of two OPC high performance concretes (HPC) were analyzed in the context of surface long-term storage. Materials were prepared with silico-calcareous aggregates (standard HPC) and hematite aggregates (heavy HPC). The initial microstructural (porosity ≈10%) and transport (gas permeability ≈10-19 m2) properties are similar for both concretes. As far as the mechanical aspect is concerned, heavy HPC shows a higher compressive strength and elastic modulus than standard HPC (78 and 63 MPa, 81 and 49 GPa, respectively). Heavy HPC is also characterized by a higher thermal conductivity (7.3 W m-1 K-1 compared to 2.7 W m-1 K-1 for standard concrete). Results analysis show that thermo-hydro-mechanical damages are smaller for heavy HPC. Between 60 and 250°C, the elastic modulus and the compressive strength of standard HPC decrease by 40% and 16%, respectively. For heavy HPC, these parameters respectively decrease by 10% and 4%. A similar trend was observed for thermal conductivity evolution. Gas permeability and porosity data confirm the good behavior of heavy HPC. As a conclusion, hematite HPC seems to provide more interesting T-H-M residual properties than standard HPC. Limited thermal expansion and thermal gradients induced by hematite are probably responsible of this behavior.

scholarly journals Effect of Fiber on Residual Strength and High Temperature Burst Performance of Ultra High Performance Concrete

2021 ◽  
pp. 224-231
Author(s):  
Huijie Shang, Qianqian Peng
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Mass Loss ◽  
Ultrasonic Wave ◽  
Wave Velocity ◽  
Residual Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Ultra High Performance Concrete ◽  
Burst Performance

In this paper, the effects of fiber on the residual strength and high temperature burst performance of ultra-high performance concrete are studied. This paper analyzes the performance change law of concrete after high temperature from three aspects: mass loss, ultrasonic wave velocity and compressive strength. The results show that with the increase of heating temperature, the mass loss increases and the ultrasonic wave velocity decreases. The compressive strength of concrete increases gradually before 300 ℃ and decreases gradually after 400 ℃. Mixing PVA fiber and steel fiber can not only improve the burst resistance of ultra-high performance concrete at high temperature, but also have high residual strength. This paper discusses the high temperature burst mechanism of ultra-high performance concrete, which is caused by the change of steam pressure and microstructure.

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.

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