High-Performance Concrete: Influence of Coarse Aggregates on Mechanical Properties

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 .

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

Science and Engineering of Composite Materials ◽

10.1515/secm-2020-0018 ◽

2020 ◽

Vol 27 (1) ◽

pp. 186-195 ◽

Cited By ~ 1

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.

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Mechanical properties and durability of high - performance concrete for bridge decks

PCI Journal ◽

10.15554/pcij.07012008.108.130 ◽

2008 ◽

Vol 53 (4) ◽

pp. 108-130

Author(s):

Mohsen A. Issa ◽

Atef A. Khalil ◽

Shahidul Islam ◽

Paul D. Krauss

Keyword(s):

Mechanical Properties ◽

High Performance ◽

High Performance Concrete ◽

Bridge Decks

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Investigation of mechanical properties and shrinkage of ultra-high performance concrete: Influence of steel fiber content and shape

Composites Part B Engineering ◽

10.1016/j.compositesb.2019.107021 ◽

2019 ◽

Vol 174 ◽

pp. 107021 ◽

Cited By ~ 18

Author(s):

Zemei Wu ◽

Caijun Shi ◽

Kamal Henri Khayat

Keyword(s):

Mechanical Properties ◽

High Performance ◽

Steel Fiber ◽

High Performance Concrete ◽

Fiber Content ◽

Ultra High Performance Concrete

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

Materials ◽

10.3390/ma14092455 ◽

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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Comparative Study of High-Performance Concrete Characteristics and Loading Test of Pretensioned Experimental Beams

Crystals ◽

10.3390/cryst11040427 ◽

2021 ◽

Vol 11 (4) ◽

pp. 427

Author(s):

Pavlina Mateckova ◽

Vlastimil Bilek ◽

Oldrich Sucharda

Keyword(s):

Mechanical Properties ◽

High Performance ◽

High Performance Concrete ◽

Raw Materials ◽

Load Capacity ◽

Materials Testing ◽

Loading Test ◽

Conventional Concrete ◽

Concrete Mechanical Properties ◽

Normal Strength

High-performance concrete (HPC) is subjected to wide attention in current research. Many research tasks are focused on laboratory testing of concrete mechanical properties with specific raw materials, where a mixture is prepared in a relatively small amount in ideal conditions. The wider utilization of HPC is connected, among other things, with its utilization in the construction industry. The paper presents two variants of HPC which were developed by modification of ordinary concrete used by a precast company for pretensioned bridge beams. The presented variants were produced in industrial conditions using common raw materials. Testing and comparison of basic mechanical properties are complemented with specialized tests of the resistance to chloride penetration. Tentative expenses for normal strength concrete (NSC) and HPC are compared. The research program was accomplished with a loading test of model experimental pretensioned beams with a length of 7 m made of ordinarily used concrete and one variant of HPC. The aim of the loading test was to determine the load–deformation diagrams and verify the design code load capacity calculation method. Overall, the article summarizes the possible benefits of using HPC compared to conventional concrete.

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