scholarly journals INFLUENCE OF CORUNDUM AS COARSE AGGREGATE IN HIGH-PERFORMANCE CONCRETE ON PROJECTILE IMPACT RESISTANCE

2019 ◽  
Vol 22 ◽  
pp. 62-66
Author(s):  
Michal Mára ◽  
Zdeňka Říhová ◽  
Markéta Kočová
Keyword(s):  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Impact Resistance ◽  
3D Scanner ◽  
Depth Of Penetration ◽  
Projectile Impact ◽  
Steel Fibre Reinforced Concrete ◽  
Coarse Aggregates ◽  
Different Types

The aim of this paper is focused on the influence of corundum as coarse aggregate in high-performance concrete on projectile impact resistance in terms of depth of penetration and size of the crater. Based on the experimental programme, samples of high-performance steel-fibre-reinforced concrete with different types and quantities of coarse aggregates were designed and produced, to be subjected to impact loading in the form of projectile impact. Damaged samples were scanned using a 3D scanner and their surface was evaluated. The goal of the paper was to find the optimum content of coarse aggregate in the mixture in order to improve its resistance against projectile impact.

scholarly journals Resistance of an Optimized Ultra-High Performance Fiber Reinforced Concrete to Projectile Impact

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 63
Author(s):  
Anna L. Mina ◽  
Michael F. Petrou ◽  
Konstantinos G. Trezos
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Depth Of Penetration ◽  
Projectile Impact ◽  
High Performance Fiber

The scope of this paper is to investigate the performance of ultra-high performance fiber reinforced concrete (UHPFRC) concrete slabs, under projectile impact. Mixture performance under impact loading was examined using bullets with 7.62 mm diameter and initial velocity 800 m/s. The UHPFRC, used in this study, consists of a combination of steel fibers of two lengths: 6 mm and 13 mm with the same diameter of 0.16 mm. Six composition mixtures were tested, four UHPFRC, one ultra-high performance concrete (UHPC), without steel fibers, and high strength concrete (HSC). Slabs with thicknesses of 15, 30, 50, and 70 mm were produced and subjected to real shotgun fire in the field. Penetration depth, material volume loss, and crater diameter were measured and analyzed. The test results show that the mixture with a combination of 3% 6 mm and 3% of 13 mm length of steel fibers exhibited the best resistance to projectile impact and only the slabs with 15 mm thickness had perforation. Empirical models that predict the depth of penetration were compared with the experimental results. This material can be used as an overlay to buildings or to construct small precast structures.

scholarly journals Effect of Corundum and Basalt Aggregates on the Ballistic Resistance of UHP-SFRC

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1529
Author(s):  
Michal Mára ◽  
Přemysl Kheml ◽  
Kristýna Carrera ◽  
Jindřich Fornůsek ◽  
Radoslav Sovják
Keyword(s):  
High Performance ◽  
Mechanical Energy ◽  
3D Scanner ◽  
Depth Of Penetration ◽  
Steel Fibre Reinforced Concrete ◽  
Ballistic Resistance ◽  
Advanced Composite ◽  
Steel Core ◽  
Full Metal Jacket ◽  
Positive Effect

Ultra-high-performance steel-fibre-reinforced concrete (UHP-SFRC) is a technologically advanced composite with a high ability to absorb and dissipate mechanical energy. This work investigates the possibility of increasing ballistic resistance by adding different percentages of corundum and basalt aggregate into this type of concrete. The most common type of ammunition, a 7.62 mm × 39 mm calibre with a full-metal jacket and a mild-steel core (FMJ-MSC), was used to test all samples. The size of the damage and the mode of failure were determined using a 3D scanner operating on the principle of photogrammetry. The experimental campaign showed that the addition of basalt and, especially, corundum aggregate has a positive effect on ballistic resistance. In particular, the increase in compressive strength and the slight decrease in depth of penetration (DOP) was observed in the case of the usage of the corundum aggregate.

Experimental Investigation of Projectile Impact Local Damage on Cementitious Composite Slabs

2013 ◽  
Vol 486 ◽  
pp. 301-306 ◽  
Author(s):  
Tomáš Vavřiník ◽  
Jan Zatloukal
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Experimental Program ◽  
Local Damage ◽  
Fiber Reinforced ◽  
Projectile Impact ◽  
Composite Slabs

This paper describes the projectile impact resistance of cement based composite slabs. The resistance is evaluated on the basis of the presented experimental program. In the experiment, local damage was inflicted by impact of defined projectiles on specimens made from normal strength concrete (NSC), steel fiber-reinforced concrete (FRC), ultra-high performance concrete (UHPC) and ultra-high performance fiber-reinforced concrete (UHPFRC) with different fiber content. Deformable ogive-nose projectiles with diameter of 7.92 mm and mass of 8.04 g with impact velocity about 700 m/s were in the experiment hitting center of the specimens. Data from the measured and visual evaluation of specimen damage were used for comparison of specimen projectile impact resistance in relation to the used material.

Preparation and Properties of High-Performance Concrete with Ceramic Coarse Aggregate

2016 ◽  
Vol 852 ◽  
pp. 1413-1420
Author(s):  
Ben Ying Wu ◽  
Xi Wu Zhou ◽  
Jin Zhong Lu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Silica Fume ◽  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Splitting Tensile Strength ◽  
Water Penetration ◽  
Concrete Material ◽  
Coarse Aggregates

High-performance concrete was prepared by using ceramic waste as coarse aggregate. The influences of several factors, such as the contents of ceramic coarse aggregates, fly ashes and silica fumes, on the properties of concrete material were investigated. The results show that the compressive strength of semi-porcelain coarse aggregate concrete are slightly lower than that of natural concrete, and the splitting tensile strength and the ratio of compressive strength and splitting tensile strength is similar to the ones of natural concrete. After fly ash and silica fume mixed, the compressive strength, the splitting tensile strength and the resistance to water penetration of concrete with semi-porcelain coarse aggregate increase significantly with the increase of silica fume content which meet the requirements of high-performance concrete. Concrete with orcelain coarse aggregate is only suitable for low strength concrete.

scholarly journals Strength properties of high-performance concretes with carbonate coarse aggregate

2011 ◽  
Vol 9 (2) ◽  
pp. 069-076
Author(s):  
Jacek Góra
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
Strength Properties ◽  
Splitting Tensile Strength ◽  
Coarse Aggregates

High performance concretes were tested to find an effect of the three different coarse aggregates (basalt, granite and dolomite) on concrete strength properties. All the results were analyzed statistically. Splitting tensile strength of high performance concrete with dolomite aggregate was significantly higher than that of concretes with basalt and granite aggregate. The effect of dolomite aggregate on compressive strength of HPC was much more advantageous than that of granite aggregate.

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.

scholarly journals The impact of coarse aggregate shape on the behavior of self-compacting high-performance concrete

2018 ◽  
Vol 49 ◽  
pp. 00079
Author(s):  
Krzysztof Ostrowski
Keyword(s):  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Significant Proportion ◽  
Rheological Parameters ◽  
Concrete Technology ◽  
Binder Ratio ◽  
Strength And Stiffness ◽  
Aggregate Shape ◽  
The Impact

Self-Compacting High Performance Concrete (SCHPC) presents a crucial step in the development of concrete technology. The most important features of self-consolidating concrete are flowability, segregation resistance and passing ability. Generally, the rheological properties are modified by effective superplasticisers and water to binder ratio. The aim of this study is to focus on the important aspect of the impact of shape of the coarse aggregate on fresh concrete mixture properties, strength and deformability of SCHPC. Coarse aggregate is a significant proportion of the concrete volume and therefore has a meaningful influence on its quality. By appropriate selection of the shape of the grain aggregate, it is possible to affect the rheological parameters of concrete. The results presented in this study indicated that the shape of the grains of coarse aggregate has an impact on the strength and stiffness of SCHPC. Moreover, the occurrence of irregular grains of coarse aggregate causes lower slump flow and higher plastic viscosity in comparison to concrete mixtures with regular grains only. The research presented in this article is part of the author's wider research devoted to this issue.

scholarly journals Sulfate Resistance of Recycled Aggregate Concrete with GGBS and Fly Ash-Based Geopolymer

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1247 ◽  
Author(s):  
Jianhe Xie ◽  
Jianbai Zhao ◽  
Junjie Wang ◽  
Chonghao Wang ◽  
Peiyan Huang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Construction Projects ◽  
High Performance ◽  
High Performance Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Aggregate Concrete ◽  
Sulfate Resistance ◽  
Coarse Aggregates

There is a constant drive for the development of ultra-high-performance concrete using modern green engineering technologies. These concretes have to exhibit enhanced durability and incorporate energy-saving and environment-friendly functions. The object of this work was to develop a green concrete with an improved sulfate resistance. In this new type of concrete, recycled aggregates from construction and demolition (C&D) waste were used as coarse aggregates, and granulated blast furnace slag (GGBS) and fly ash-based geopolymer were used to totally replace the cement in concrete. This study focused on the sulfate resistance of this geopolymer recycled aggregate concrete (GRAC). A series of measurements including compression, X-ray diffraction (XRD), and scanning electron microscopy (SEM) tests were conducted to investigate the physical properties and hydration mechanisms of the GRAC after different exposure cycles in a sulfate environment. The results indicate that the GRAC with a higher content of GGBS had a lower mass loss and a higher residual compressive strength after the sulfate exposure. The proposed GRACs, showing an excellent sulfate resistance, can be used in construction projects in sulfate environments and hence can reduce the need for cement as well as the disposal of C&D wastes.

Sign in / Sign up

Export Citation Format

Share Document