scholarly journals EXPERIMENTAL STUDY ON THE DYNAMIC BEHAVIOR OF RUBBER CONCRETE UNDER COMPRESSION CONSIDERING EARTHQUAKE MAGNITUDE STRAIN RATE

2020 ◽  
Vol 26 (8) ◽  
pp. 733-748
Author(s):  
Furong Li ◽  
Yongyi Wu ◽  
Xinghua Xie ◽  
Kai Zhao ◽  
Zhenpeng Yu
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Strain Rate ◽  
Substitution Rate ◽  
Earthquake Magnitude ◽  
Engineering Practice ◽  
Compressive Failure ◽  
Substitution Rates ◽  
Rubber Concrete

To examine the compressive dynamic performance of rubber concrete, a uniaxial compression experimental study on rubber concrete was carried out using a hydraulic servo based on five different rubber substitution rates under eight different earthquake magnitude loading strain rates. The compressive failure modes and stress-strain curves of rubber concrete were obtained. By comparatively analyzing the mechanical characteristics of rubber concrete under different loading conditions, the following conclusions are drawn: with the increase in rubber substitution rate, the integrity of concrete upon compressive failure is gradually improved, and rubber particles exhibit an evident modification effect on cement mortar at the concrete interface. Under the influence of loading strain rate, the patterns of compressive failure mode of rubber concrete with different substitution rates are similar to that of ordinary concrete. Under the same loading strain rate, with the increase in rubber substitution rate, the compressive strength of rubber concrete gradually decreases while the plastic deformation capacity gradually increases. For the same rubber substitution rate, the compressive strength and elastic modulus of rubber concrete gradually increases with the increase in loading strain rate. The increase in rubber substitution rate gradually reduces the increasing amplitude of compressive strength and elastic modulus of rubber concrete under the influence of loading strain rate. Meanwhile, an equation was proposed to describe the coupling effect of rubber substitution rate and strain rate on the compressive strength dynamic increase factor of rubber concrete, and the underlying stress mechanism was further discussed. These results have significance in promoting the application of rubber concrete in engineering practice.

scholarly journals An Experimental Study on the Basic Mechanical Properties and Compression Size Effect of Rubber Concrete with Different Substitution Rates

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yanli Hu ◽  
Xuewei Sun ◽  
Aiqun Ma ◽  
Peiwei Gao
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Shear Strength ◽  
Size Effect ◽  
Substitution Rate ◽  
Failure Modes ◽  
Pure Shear ◽  
Specimen Size ◽  
Substitution Rates ◽  
Rubber Concrete

An experimental study was carried out on the uniaxial compression, uniaxial splitting, pure shear, and compression size effect of rubber concrete with 5 different substitution rates by applying hydraulic servo and direct shear apparatus. Then, by comparing the failure modes and ultimate strength eigenvalues of rubber concrete under different loading conditions, the following conclusions were drawn: with the increase of rubber substitution rate, the concrete specimens maintain a relatively good integrity under uniaxial compressive failure; on the contrary, the failure sections under uniaxial slitting and pure shear gradually become uneven with an increasing amount of fallen rubber particles. With the increase of specimen size, the integrity of rubber concrete after failure is gradually improved. Affected by an increased rubber substitution rate, the uniaxial compressive strength, splitting tensile strength, and shear strength of the concrete gradually decrease, while the plastic deformation capacity gradually increases. Specifically, the compressive strength is reduced by a maximum of 60.67%; the shear strength is reduced by a maximum of 49.85%; and the uniaxial splitting strength is reduced by a maximum of 58.38%. Then, we analyzed the strength relationship and the underlying mechanism among the three types of loading modes. It is found that, at the same rubber substitution rate, the compressive strength of rubber concrete gradually increases as the specimen size decreases, and the size effect on the compressive strength gradually decreases as the rubber substitution rate increases. Meanwhile, we performed qualitative and quantitative analysis on the equation describing the coupling effect of specimen size and rubber substitution rate on the compressive strength; the results suggest that the proposed equation is of a high level of applicability. Our research has a reference value for the application and promotion of rubber concrete in actual engineering projects.

scholarly journals An Experimental Study on the Compressive Dynamic Performance of Rubber Concrete under Freeze-Thaw Cycles

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Juntao Zhang ◽  
Guangli Zhang ◽  
Xinjian Sun ◽  
Wenguo Pan ◽  
Peijie Huang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Elastic Modulus ◽  
Strain Rate ◽  
Compressive Stress ◽  
Dynamic Performance ◽  
Peak Stress ◽  
Engineering Practice ◽  
Stress Strain ◽  
Freeze Thaw ◽  
Rubber Concrete

An experimental study was conducted using a hydraulic servo machine to examine the compressive dynamic performance of rubber concrete under freeze-thaw cycles by considering 4 different numbers of freeze-thaw cycles and 8 different strain rates. The compressive stress-strain curves of rubber concrete under different loading conditions were obtained. By comparatively analyzing the mechanical characteristic parameters of the compressive stress-strain curves (i.e., peak stress, elastic modulus, and peak strain), the following conclusions were drawn: at the same loading strain rate, the compressive peak stress of rubber concrete is gradually decreased while the mass loss rate is gradually increased, as the number of freeze-thaw cycles increases. Compared to ordinary concrete, rubber concrete has a better frost resistance property. At the same number of freeze-thaw cycles, the compressive peak stress and elastic modulus of rubber concrete are gradually increased as the loading strain rate increases. The increase in the number of freeze-thaw cycles enlarges the increasing amplitude of the peak stress and elastic modulus under the action of loading strain rate. The compressive peak stress and elastic modulus dynamic increase factors of rubber concrete exhibit a linear relationship with the dimensionless logarithm of the loading strain rate. Meanwhile, a calculation model was proposed for the compressive peak stress dynamic increase factor of rubber concrete under the coupling effect of freeze-thaw cycles and loading strain rate, and the corresponding stress mechanism was discussed in detail. The research findings are of great significance to the application and development of antifreeze concrete in engineering practice.

Experimental Study on Ratio of Bending-Compressive Strength of the Crumb Rubber Concrete Modified by Latex

2014 ◽  
Vol 941-944 ◽  
pp. 761-764
Author(s):  
Wei Li ◽  
Zhen Huang ◽  
Xiao Chu Wang ◽  
Zi Sheng Zang
Keyword(s):  
Mechanical Property ◽  
Experimental Study ◽  
Compressive Strength ◽  
Surface Modification ◽  
Flexural Strength ◽  
Crumb Rubber ◽  
Interface Effect ◽  
Rubber Particles ◽  
Crumb Rubber Concrete ◽  
Rubber Concrete

The cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete and improve the interface effect of rubber particles.We had researched the change regulation about the ratio of bending-compressive strength of the crumb rubber concrete modified by latex,the concrete with various quantity of rubber,under the condition dosage of latex is 0.5% of cement quality.The result of experimental prove that,compressive strength, splitting tensile and flexural strength could be enhanced because of latex injecting,and the ratio of bending-compressive strength could be enhanced at the same time.

Experimental Study on Proportion of Tensile Strength and Compressive Strength of the Crumb Rubber Concrete Modified by Latex

2014 ◽  
Vol 919-921 ◽  
pp. 1916-1919
Author(s):  
Wei Li ◽  
Zhen Huang ◽  
Xiao Chu Wang ◽  
Zi Sheng Zang
Keyword(s):  
Mechanical Property ◽  
Experimental Study ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Surface Modification ◽  
Flexural Strength ◽  
Crumb Rubber ◽  
Rubber Particles ◽  
Crumb Rubber Concrete ◽  
Rubber Concrete

The cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete and improve the interface effect of rubber particles.We had researched the change regulation of the ratio between tensile strength and compressive strength of the Crumb Rubber Concrete Modified by latex,the concrete with various quantity of rubber,under the condition Dosage of latex is 0.5% of cement quality.The result of Experimental prove that,compressive strength, splitting tensile and flexural strength could be enhanced because of latex injecting,and the ratio between tensile strength and compressive strength could be enhanced at the same time.

Experimental and Numerical Analysis of Qinling Mountain Engineered Rocks during Pulse-Shaped SHPB Test

2015 ◽  
Vol 16 (3-4) ◽  
pp. 165-171
Author(s):  
Shi Liu ◽  
Jinyu Xu
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Strain Rate ◽  
Energy Absorption ◽  
Absorption Rate ◽  
Failure Modes ◽  
Dynamic Compression ◽  
Peak Strain ◽  
Compression Stress ◽  
Dynamic Compressive Strength

AbstractIn order to study the dynamic compression mechanical properties of engineering rock under high strain rate （100~102 S−1）loads, dynamic compression tests of three common engineering rocks (marble, sandstone and granite) taken from the Qinling Mountain are studied subjected to five different kinds of shock air pressure using Φ 100 mm split Hopkinson pressure bar test system improved with purple copper waveform shaper. The dynamic compression stress-strain curves, dynamic compressive strength, peak strain, energy absorption rate and elastic modulus of three rocks variation with strain rate are researched. The dynamic compression failure modes under different strain rates are analyzed. Then the three-dimensional numerical simulations of waveform shaper shaping effects and stress wave propagation in the SHPB tests are carried out to reproduce the test results. The research results show that the dynamic compression stress-strain curves show certain discreteness, and there is an obvious rebound phenomenon after the peak. With the increase in strain rate, the dynamic compressive strength, peak strain and energy absorption rate are all in a certain degree of increase, but the elastic modulus have no obvious change trend. Under the same strain rate, the dynamic compressive strength of granite is greatest while of sandstone is least. With the increase in strain rate, the margin of increase in peak strain and energy absorption rate of granite is greatest while of sandstone is least. The failure modes of the sample experience a developing process from outside to inside with the increase of strain rate.

scholarly journals Experimental Study on Freeze-Thaw Effects on Creep Characteristics of Rubber Concrete

2022 ◽  
Vol 2022 ◽  
pp. 1-14
Author(s):  
Qi Li ◽  
Fei Xu ◽  
Hemin Zheng ◽  
Junhao Shi ◽  
Jianyu Zhang
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Stress Level ◽  
Creep Behavior ◽  
Mass Loss Rate ◽  
Crumb Rubber ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw ◽  
Stress Levels ◽  
Rubber Concrete

Crumb Rubber Concrete (CRC) can exhibit high freeze-thaw resistance, but its long-term creep behavior under various freeze-thaw conditions remains unclear, which is essential for the safety of pavement engineering in the severe cold zone. In this study, the freeze-thaw effects on the creep behavior of CRC under different stress levels were systematically analyzed by testing the compressive strength, the uniaxial creep under different stress levels, and the dynamic elastic modulus. To simulate real conditions of the road environment in the cold area, the lowest temperature of −20°C, six freeze-thaw cycles of 0, 30, 60, 90, 120, and 150, and seven different stress levels of 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9 of the compressive strength were employed in this study. The test results showed that the mass loss rate was 6%–11.2% and the compressive strength decreased by 6.51%–47% after 30–150 freeze-thaw cycles. When the stress level reached its critical value, the relative dynamic elastic modulus decreased with the number of freeze-thaw cycles. After 150 freeze-thaw cycles, failure did not appear when the stress level was lower than 50%, above which the creep failure was determined by the stress level and the number of the freeze-thaw cycles. Meanwhile, it was found that the cracking and interfacial debonding between the matrix and the crumb rubber particle were the main reasons for the degradation of CRC creep performance. Finally, a Weibull distribution-based empirical creep damage model was established to predict the failure of CRC, which can enhance its application to related engineering.

scholarly journals Analysis and Prediction of Compressive Properties for Steel Fiber-and-Nanosilica-Reinforced Crumb Rubber Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Danying Gao ◽  
Tao Zhang ◽  
Yihong Wang ◽  
Yiming Kong ◽  
Dawei Li ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Volume Content ◽  
Steel Fiber ◽  
Crumb Rubber ◽  
Steel Fibers ◽  
Peak Strain ◽  
Compressive Properties ◽  
Crumb Rubber Concrete ◽  
Rubber Concrete

The disposal of waste tire rubber has gained more attention from the viewpoint of green, environmental protection, and sustainability. Numerous attempts have been stated on the properties of crumb rubber concrete (CRC) and observed that there is a large reduction of compressive strength and elastic modulus of CRC with the increase of the rubber substitution rate. Based on the CRC with the crumb rubber volume content of 5%, the steel fibers and nanosilica were added to CRC to make steel fiber-and-nanosilica-reinforced crumb rubber concrete (SFNS-CRC) in this paper. The effects of the steel fiber volume content and nanosilica content on the compressive properties of SFNS-CRC were studied, including compressive strength, elastic modulus, peak strain, compression toughness, and failure pattern. The test results indicated that the modulus of elasticity and compressive strength of SFNS-CRC have the increasing tendency with the addition of steel fibers and nanosilica. Moreover, the peak strains have a significant increase with the increase of the steel fiber content and nanosilica replacement ratio. The compressive stress-strain curves of SFNS-CRC gradually plump with the increase of the steel fibers and nanosilica. Finally, the prediction formulas for the compressive strength, elastic modulus, and peak strain of SFNS-CRC were set up. A simple predicted model of the stress-strain curve for SFNS-CRC was proposed, which considers the effect of steel fibers and nanosilica.

Experimental Study on the Compressive Strength and Frost Resistance of Rubber Concrete

2013 ◽  
Vol 433-435 ◽  
pp. 2016-2019
Author(s):  
Qun Yu ◽  
Wen Chao Ye
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Frost Resistance ◽  
Experimental Studies ◽  
Maintenance Period ◽  
Concrete Compressive Strength ◽  
Compression Performance ◽  
Rubber Particles ◽  
Rubber Concrete

Experimental studies on the compressive strength and frost resistance of rubber concrete during different maintenance period have been carried through in this paper. The results show that: the concrete compressive strength reduces with the incorporation of rubber particles, but its frost resistance increases, and with the growth of the maintenance period, its compression performance increases; however, its frost resistance remained unchanged.

The Compressive Strength of Ice Cubes of Different Sizes

1993 ◽  
Vol 115 (2) ◽  
pp. 142-148 ◽  
Author(s):  
G. A. Kuehn ◽  
E. M. Schulson ◽  
D. E. Jones ◽  
J. Zhang
Keyword(s):  
Grain Size ◽  
Compressive Strength ◽  
Boundary Conditions ◽  
Strain Rate ◽  
Side Length ◽  
Failure Strength ◽  
Loading Conditions ◽  
Compressive Failure ◽  
Loading Surface

Cubes of side length from 10 to 150 mm were prepared from freshwater granular ice of about 1 mm grain size and then compressed uniaxially to failure at −10° C. In addition to size, the variables were strain rate (10−5s−1 and 10−2s−1) and boundary conditions (ground brass plates, ground and polished brass plates, and brass brushes). The results showed that over the range investigated, size is not an important factor when considering the ductile compressive strength of ice. It also appears that size is not a factor when considering the brittle compressive failure strength under more ideal loading conditions. However, under less ideal conditions where perturbations on the loading surface may be significant, the brittle compressive strength decreases as the size of cube increases. In this case, the effect is attributed to nonsimultaneous failure.

scholarly journals Experimental Study on Damage and Failure of Coal-Pillar Dams in Coal Mine Underground Reservoir under Dynamic Load

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Qiangling Yao ◽  
Liqiang Yu ◽  
Ning Chen ◽  
Weinan Wang ◽  
Qiang Xu
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Strain Rate ◽  
Water Content ◽  
Dynamic Loading ◽  
Coal Pillar ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Underground Reservoir

The stability of coal-pillar dams in underground hydraulic engineering works is affected not only by long-term water erosion but also by dynamic loading induced, for example, by roof breaking or fault slipping. In this paper, the water absorption characteristics of coal samples from western China were studied by nondestructive immersion tests, and a high-speed camera was used to monitor SHPB tests on samples of varying water content and subjected to various strain rates. Besides, the coal-pillar dam is numerically simulated based on the experimental data and the actual engineering conditions. The results show that, given low strain rate and high water content, the compaction stage accounts for most of the stress-strain curve, whereas the elastic stage accounts for only a relatively small fraction of the stress-strain curve. The dynamic compressive strength and elastic modulus follow exponential and logarithmic functions of strain rate, respectively, exhibiting a significant positive correlation. As the water content increases, the dynamic elastic modulus increases almost linearly, and the compressive strength decreases gradually. Under the same impact load, samples with greater water content fail more rapidly, and the failure is exacerbated by the propagation of parallel cracks to staggered cracks. The average size of coal fragments decreases linearly with increasing strain rate and water content. Simulations indicate that dynamic loading increases the stress concentration on both sides of the dam and expands the high-stress area and plastic zone. The results provide guidance for designing waterproof coal pillars and underground reservoir dams.

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