scholarly journals Static mechanical properties and mechanism of C200 ultra-high performance concrete (UHPC) containing coarse aggregates

2020 ◽  
Vol 27 (1) ◽  
pp. 186-195 ◽  
Author(s):  
Lv Yujing ◽  
Zhang Wenhua ◽  
Wu Fan ◽  
Wu Peipei ◽  
Zeng Weizhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Maximum Size ◽  
X Ray Diffraction ◽  
Ultra High Performance Concrete ◽  
Coarse Aggregates ◽  
Static Mechanical ◽  
Static Mechanical Properties

AbstractIn this paper, C200 ultra-high performance concrete (UHPC) containing coarse aggregate was prepared. Firstly, four different maximum size and three different type of coarse aggregate having significant differences in strength, surface texture, porosity and absorption were used to prepared the mixtures. Secondly, the effect of maximum size and type of coarse aggregate on the workability of the fresh UHPC and the mechanical behaviour of harden UHPC were investigated. Finally, a series micro-tests including mercury intrusion porosimetry (MIP), scanning electron microscope (SEM), X-ray diffraction (XRD) were conducted and the mechanism of the C200 UHPC were discussed.The results show that the type and maximum size of coarse aggregate have significant effect on the workability and mechanical properties of C200 UHPC. The basalt coarse aggregate with maximum size of 10mm can be used to prepare the C200 UHPC. The compressive strength and flexural strength of the C200 UHPC is 203MPa and 46MPa at 90 day, respectively. Besides, the micro-tests data show that the C200 UHPC has a compacted matrix and strong interface transition zone (ITZ), which make the aggregate potential strength fully used.

Influence of the Type of Silica Fume on the Rheological and Mechanical Properties of Ultra-High Performance Concrete

2011 ◽  
Vol 488-489 ◽  
pp. 274-277 ◽  
Author(s):  
Kyung Taek Koh ◽  
Jung Jun Park ◽  
Su Tae Kang ◽  
Gum Sung Ryu
Keyword(s):  
Mechanical Properties ◽  
Surface Area ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Materials ◽  
Ultra High Performance Concrete ◽  
Coarse Aggregates ◽  
Surface Areas ◽  
Compressive And Flexural Strengths

Ultra-high performance concrete (UHPC) is a new generation of concrete developed through microstructure enhancement techniques for cementitious materials. UHPC exhibits extremely high compressive and flexural strengths exceeding 180 and 30 MPa, respectively, and remarkable durability compared to normal concretes. The fabrication of UHPC requires very low W/B ratio reaching merely 0.2, the use of large quantities of fine binder and superplasticizer without coarse aggregates, and the incorporation of steel micro-fibers. This study investigates the effect of the type of silica fume on the rheological and mechanical properties of UHPC. The adopted silica fume presents various contents of SiO2 and surface areas. From the experimental results, UHPC using silica fume with 94% of SiO2 3% of ZrO2, and surface area of 80,000 g/cm3 shows better flowability than UHPC using silica fume with 98% of SiO2and surface area of 200,000 g/cm3 by lowering the viscosity of the cementitious composites without decreasing the compressive strength. Therefore, the fabrication cost of UHPC can be reduced by smaller dosage of superplasticizer when using silica fume with Zr content .

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.

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.

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.

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