The dynamic properties behavior of high strength concrete under different strain rate

2005 ◽  
Author(s):  
Hasballah Abdullah ◽  
Saiful Husin ◽  
Hamdani Umar ◽  
Samsul Rizal
Keyword(s):  
Strain Rate ◽  
High Strength Concrete ◽  
Dynamic Properties ◽  
High Strength ◽  
Strength Concrete

Compressive Behavior of Plain and Fiber-Reinforced High-Strength Concrete Subjected to High Strain Rate Loading

2011 ◽  
Vol 82 ◽  
pp. 57-62 ◽  
Author(s):  
Sha Sha Wang ◽  
Min Hong Zhang ◽  
Ser Tong Quek
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strength Concrete ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
High Strength ◽  
Strain Rates ◽  
Compressive Behavior ◽  
High Strain Rates ◽  
Strength Concrete

This paper presents a laboratory experimental study on the effect of high strain rate on compressive behavior of plain and fiber-reinforce high-strength concrete (FRHSC) with similar strength of 80-90 MPa. Steel fibers, polyethylene fibers, and a combination of these were used in the FRHSC. A split Hopkinson pressure bar equipment was used to determine the concrete behavior at strain rates from about 30 to 300 s-1. The ratio of the strength at high strain rates to that at static loading condition, namely dynamic increase factor (DIF), of the concretes was determined and compared with that recommended by CEB-FIP code. Fracture patterns of the specimens at high strain rates are described and discussed as well. Results indicate that the CEB-FIP equation is applicable to the plain high strength concrete, but overestimates the DIF of the FRHSC at strain rates beyond a transition strain rate of 30 s-1. Based on the experimental results, a modified equation on DIF is proposed for the FRHSC.

scholarly journals An Experimental Study on the Dynamic Behavior of an Ultra High-Strength Concrete

2020 ◽  
Vol 10 (12) ◽  
pp. 4170
Author(s):  
Ahmet Reha Gunay ◽  
Sami Karadeniz ◽  
Mustafa Kaya
Keyword(s):  
Compressive Strength ◽  
High Strain Rate ◽  
Strain Rate ◽  
Dynamic Behavior ◽  
High Strength Concrete ◽  
High Strain ◽  
High Strength ◽  
High Energy ◽  
Static Compression ◽  
Strength Concrete

Ultra-high-strength concrete is a newly developed construction material that has a minimum 120 MPa or higher compressive strength. Recently, the usage of high-strength and ultra-high-strength concretes has become widespread due to the enhancement of the concrete technology. Many civil engineering structures constructed by using concrete materials are usually subjected to, in addition to static loads, dynamic loads due to earthquakes, wind and storm, impact and blast, which take place under high energy and high strain rate values. The effects of such loadings on the structure must be understood thoroughly. In recent years, the withstanding of a structure on these loading conditions has become a crucial issue for its impact on the economy and human safety. One of the approaches to fulfill these requirements is to develop high-strength or ultra high-strength concretes (UHSCs). In this study, an ultra-high-strength concrete with a compressive strength of 135 MPa was designed and developed. In order to determine the dynamic behavior of this UHSC, the specimens at three height/diameter ratios (approximately, 0.6, 1.0 and 1.2) were extracted from the prepared concrete mixtures. These concrete specimens were tested to determine both the quasi-static and dynamic compressive behaviors of the developed concrete. In the quasi-static compression tests, cylindrical specimens and a conventional compressive testing machine were used. In order to study the dynamic compressive behavior, a Split Hopkinson Pressure Bar (SHPB) test setup was used. In this test system, the time variations of compressive strength, the strain and strain rates under uniaxial pressure loading were experimentally evaluated and the deformation and fracturing processes of the specimens were recorded using a high-speed camera. The test results, based on the testing of 21 different specimens, have shown that the dynamic compressive strength values of the developed concrete varied in the range of 143 to 253 MPa, while the strain rate values varied in the range of 353 s−1 to 1288 s−1. Using the data generated in the SHPB tests, the parameters present in a Johnson–Holmquist–Cook concrete material model, which is used in numerical studies on the high strain rate behavior of concretes, were evaluated.

scholarly journals Nonlinear Mechanical Effect of Free Water on the Dynamic Compressive Strength and Fracture of High-Strength Concrete

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4011
Author(s):  
Evgeny V. Shilko ◽  
Igor S. Konovalenko ◽  
Ivan S. Konovalenko
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
High Strength Concrete ◽  
Large Scale ◽  
Pore Space ◽  
Free Water ◽  
High Strength ◽  
Darcy Number ◽  
Sigmoid Function ◽  
Strength Concrete

It is well-known that the effect of interstitial fluid on the fracture pattern and strength of saturated high-strength concrete is determined by qualitatively different mechanisms at quasi-static and high strain rate loading. This paper shows that the intermediate range of strain rates (10−4 s−1 < ε˙ < 100 s−1) is also characterized by the presence of a peculiar mechanism of interstitial water effect on the concrete fracture and compressive strength. Using computer simulations, we have shown that such a mechanism is the competition of two oppositely directed processes: deformation of the pore space, which leads to an increase in pore pressure; and pore fluid flow. The balance of these processes can be effectively characterized by the Darcy number, which generalizes the notion of strain rate to fluid-saturated material. We have found that the dependence of the compressive strength of high-strength concrete on the Darcy number is a decreasing sigmoid function. The parameters of this function are determined by both low-scale (capillary) and large-scale (microscopic) pore subsystems in a concrete matrix. The capillary pore network determines the phenomenon of strain-rate sensitivity of fluid-saturated concrete and logistic form of the dependence of compressive strength on strain rate. Microporosity controls the actual boundary of the quasi-static loading regime for fluid-saturated samples and determines localized fracture patterns. The results of the study are relevant to the design of special-purpose concretes, as well as the assessment of the limits of safe impacts on concrete structural elements.

scholarly journals Dynamic Tensile Properties and Energy Dissipation of High-Strength Concrete after Exposure to Elevated Temperatures

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5313 ◽  
Author(s):  
Nao Lv ◽  
Hai-bo Wang ◽  
Qi Zong ◽  
Meng-xiang Wang ◽  
Bing Cheng
Keyword(s):  
Tensile Strength ◽  
Strain Rate ◽  
High Temperatures ◽  
High Strength Concrete ◽  
Elevated Temperatures ◽  
Coarse Aggregate ◽  
High Strength ◽  
Dynamic Tensile Strength ◽  
Strength Concrete ◽  
Propagation Law

In view of the devastating outcomes of fires and explosions, it is imperative to research the dynamic responses of concrete structures at high temperatures. For this purpose, the effects of the strain rate and high temperatures on the dynamic tension behavior and energy characteristics of high-strength concrete were investigated in this paper. Dynamic tests were conducted on high-strength concrete after exposure to the temperatures of 200, 400, and 600 °C by utilizing a 74 mm diameter split Hopkinson pressure bar (SHPB) apparatus. We found that the quasi-static and dynamic tensile strength of high-strength concrete gradually decreased and that the damage degree rose sharply with the rise of temperature. The dynamic tensile strength and specific energy absorption of high-strength concrete had a significant strain rate effect. The crack propagation law gradually changed from directly passing through the coarse aggregate to extending along the bonding surface between the coarse aggregate and the mortar matrix with the elevation of temperature. When designing the material ratio, materials with high-temperature resistance and high tensile strength should be added to strengthen the bond between the mortar and the aggregate and to change the failure mode of the structure to resist the softening effect of temperature.

scholarly journals Effect of Cylinder Size on the Modulus of Elasticity and Compressive Strength of Concrete from Static and Dynamic Tests

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Byung Jae Lee ◽  
Seong-Hoon Kee ◽  
Taekeun Oh ◽  
Yun-Yong Kim
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Elastic Moduli ◽  
Dynamic Properties ◽  
High Strength ◽  
Primary Objective ◽  
Dynamic Tests ◽  
Strength Concrete ◽  
Dynamic Elastic Moduli ◽  
Static And Dynamic Tests

The primary objective of this study is to investigate the effects of cylinder size (150 by 300 mm and 100 by 200 mm) on empirical equations that relate static elastic moduli and compressive strength and static and dynamic elastic moduli of concrete. For the purposes, two sets of one hundred and twenty concrete cylinders, 150 by 300 mm and 100 by 200 mm, were prepared from three different mixtures with target compressive strengths of 30, 35, and 40 MPa. Static and dynamic tests were performed at 4, 7, 14, and 28 days to evaluate compressive strength and static and dynamic moduli of cylinders. The effects of the two different cylinder sizes were investigated through experiments in this study and database collected from the literature. For normal strength concrete (≤40 MPa), the two different cylinder sizes do not result in significant differences in test results including experimental variability, compressive strength, and static and dynamic elastic moduli. However, it was observed that the size effect became substantial in high strength concrete greater than 40 MPa. Therefore, special care is still needed to compare the static and dynamic properties of high strength concrete from the two different cylinder sizes.

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