scholarly journals Numerical Simulation of the Effect of Loading Angle on Initial Cracks Position Point: Application to the Brazilian Test

2021 ◽  
Vol 11 (8) ◽  
pp. 3573
Author(s):  
Meriem Fakhreddine Bouali ◽  
Mounir Bouassida
Keyword(s):  
Numerical Simulation ◽  
Tensile Strength ◽  
Brazilian Test ◽  
Indirect Tensile Strength ◽  
Brazilian Disk ◽  
Initiation Point ◽  
Indirect Tensile ◽  
The Impact ◽  
Initial Cracks ◽  
Distribution Of Stresses

The Brazilian Test is the most used test to determine the indirect tensile strength for brittle materials like concrete. It has been observed that the success of the test depends on the cracks initiation point position and therefore the arch loading angle; a crack appears in the center of the disk when the test is valid. To this effect, using Fast Lagrangian of Continua code FLAC2D; numerical analyses were performed to study the impact of the arch loading angle on the initial crack’s position in a 70 mm diameter Brazilian disk of concrete and mortar under loading arch 2α which varies from 5–45°. The distribution of stresses and the tensile strength at the center of the Brazilian disk obtained numerically was closely similar to analytical and experimental existing solutions. The results showed that to obtain a meaningful and validated test with the most accurate indirect tensile strength, it is recommended to take a loading arch 2α ≥ 20° for the concrete and 2α ≥ 10° for the mortar.

Research on Performance of Emulsion Asphalt Cold Reclaimed Mixture with Various RAP Contents

2011 ◽  
Vol 255-260 ◽  
pp. 3432-3436
Author(s):  
Xian Yuan Tang ◽  
Jie Xiao
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Compression Test ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Beam Test ◽  
Reclaimed Asphalt ◽  
Indirect Tensile ◽  
The Impact

This paper systematically elaborates the impact upon performance of emulsion asphalt cold reclaimed asphalt mixture by different RAP contents, through a series of testing on six cold reclaimed asphalt mixtures with various RAP contents, such as single axle compression test, 15°C indirect tensile strength (ITS) test, 40°C rutting test and -10°C low-temperature bending beam test. Testing results indicate that 15°C ITS decreases from around 0.75 MPa to 0.58 MPa with the RAP content of mixture increasing from 0% to 100%. 40°C dynamic stabilities reduce considerably from around 19,000 time/mm of 0% RAP mixture to 3,600 time/mm of 100% RAP mixture. -10°C failure strains only change from 1500με to 2000με.

scholarly journals Pengaruh Air Mengunakan Reclaimed Asphalt Pavement Pada Campuran Beton Aspal Berdasarkan Uji Cantabro Dan Indirect Tensile Strength

2021 ◽  
Vol 10 (1) ◽  
pp. 30-40
Author(s):  
Tommy Iduwin ◽  
Devita Mayasari ◽  
Tri Yuhanah
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Indirect Tensile Strength ◽  
Reclaimed Asphalt Pavement ◽  
Test Results ◽  
Reclaimed Asphalt ◽  
Marshall Test ◽  
Indirect Tensile ◽  
Asphalt Content ◽  
The Impact

The impact of RAP on water was identified to be analyzed for the material's resistance to water because there are still a lot of waterlogged pavements in Indonesia. This research uses RAP variation 0%, 25% and 35%. The test is the Marshall test to get the optimum asphalt content value, the Cantabro test to determine the weight loss for 300 rounds and the durability by varying the immersion 0.1, 2, 4 and 7 days which will be tested for ITS. The KAO value obtained for each variation is 5.4% for 0% Rap, 5.6 for 25% Rap and 6% for 35% RAP. The results of the Cantabro test show that the largest percentage of weight loss is a mixture of 35% RAP which is 12.54%, where for 0% RAP there is a weight loss of 10.85% and at 25% RAP there is a weight loss of 11.66%. ITS test results have the highest value with variations of RAP 0%, RAP 25% and RAP 35%. variations of 0%, 25% and 35% showed a decreasing trend until the 7th day of immersion, it can be said that in the three variations the ITS value was influenced by the duration of continuous immersion. Keywords: RAP, AC-WC, Marshall, Cantabro, Indirect Tensile Strength

scholarly journals A Novel Analytical Solution for the Brazilian Test with Loading Arcs

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
R. Gutiérrez-Moizant ◽  
M. Ramírez-Berasategui ◽  
S. Santos-Cuadros ◽  
C. C. García-Fernández
Keyword(s):  
Finite Element ◽  
Tensile Strength ◽  
Indirect Tensile Strength ◽  
Finite Element Models ◽  
The Finite Element Method ◽  
Contact Pressure Distribution ◽  
Brazilian Disk ◽  
New Model ◽  
Proposed Model ◽  
Indirect Tensile

This research study presents a new theoretical model to calculate the indirect tensile strength for the Brazilian disk with loading arcs, based on numerical simulations, two-dimensional elasticity theory, and Griffith failure criterion. The new expression incorporates a no uniform contact pressure distribution determined by the results of the simulations with the finite element method. A computational experiment design has been developed to test the accuracy of the predictions made with the proposed model. This study demonstrates that the stresses predicted with the new model are closer to those determined by the finite element models than other theoretical solutions available in the literature. Additionally, a comparative analysis with experimental results obtained by other authors also indicates that the new model provides a more accurate magnitude of the indirect tensile strength.

Performance Comparison of Asphalt Emulsion Stabilized Granular Base Modified with Cement or Asphaltenes

2021 ◽  
Author(s):  
Muhammad Misbah Uddin ◽  
Farshad Kamran ◽  
Leila Hashemian
Keyword(s):  
Tensile Strength ◽  
Oil Sands ◽  
Performance Comparison ◽  
Indirect Tensile Strength ◽  
Asphalt Emulsion ◽  
Performance Properties ◽  
Low Temperature Cracking ◽  
Indirect Tensile ◽  
Base Course ◽  
The Impact

Asphalt emulsion is a common material used for pavement base course stabilization, and cement is usually added as an active filler to improve the stability of asphalt emulsion mixtures further. However, using cement in these mixes has several drawbacks, including high material costs and environmental issues. On the other hand, asphaltenes is a waste by product derived from the processing of Alberta oil-sands bitumen that could be used for the same purpose. This investigation compares the impact of cement and asphaltenes as additives to asphalt emulsion-stabilized layers. To compare the performance properties, cement- and asphaltenes-modified mixtures are prepared at different concentrations. The performance properties of the modified mixtures are investigated by conducting a series of tests including Marshall stability, indirect tensile strength, IDEAL-CT, and tensile strength ratio. In addition, to evaluate low-temperature cracking resistance of the mixtures, indirect tensile strength test is conducted at 0 °C and −10 °C.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

scholarly journals Rejuvenation Mechanism of Asphalt Mixtures Modified with Crumb Rubber

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 370-384
Author(s):  
Hossein Noorvand ◽  
Kamil Kaloush ◽  
Jose Medina ◽  
Shane Underwood
Keyword(s):  
Tensile Strength ◽  
Dynamic Loading ◽  
Creep Compliance ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Indirect Tensile Strength ◽  
Laboratory Evaluation ◽  
Strength Testing ◽  
Noise Mitigation ◽  
Indirect Tensile

Asphalt aging is one of the main factors causing asphalt pavements deterioration. Previous studies reported on some aging benefits of asphalt rubber mixtures through laboratory evaluation. A field observation of various pavement sections of crumb rubber modified asphalt friction courses (ARFC) in the Phoenix, Arizona area indicated an interesting pattern of transverse/reflective cracking. These ARFC courses were placed several years ago on existing jointed plain concrete pavements for highway noise mitigation. Over the years, the shoulders had very noticeable and extensive cracking over the joints; however, the driving lanes of the pavement showed less cracking formation in severity and extent. The issue with this phenomenon is that widely adopted theories that stem from continuum mechanics of materials and layered mechanics of pavement systems cannot directly explain this phenomenon. One hypothesis could be that traffic loads continually manipulate the pavement over time, which causes some maltenes (oils and resins) compounds absorbed in the crumb rubber particles to migrate out leading to rejuvenation of the mastic in the asphalt mixture. To investigate the validity of such a hypothesis, an experimental laboratory testing was undertaken to condition samples with and without dynamic loads at high temperatures. This was followed by creep compliance and indirect tensile strength testing. The results showed the higher creep for samples aged with dynamic loading compared to those aged without loading. Higher creep compliance was attributed to higher flexibility of samples due to the rejuvenation of the maltenes. This was also supported by the higher fracture energy results obtained for samples conditioned with dynamic loading from indirect tensile strength testing.

scholarly journals Evaluations of Nano-Sized Hydrated Lime on the Moisture Susceptibility of Hot Mix Asphalt Mixtures

2012 ◽  
Vol 174-177 ◽  
pp. 82-90 ◽  
Author(s):  
Ju Nan Shen ◽  
Zhao Xing Xie ◽  
Fei Peng Xiao ◽  
Wen Zhong Fan
Keyword(s):  
Tensile Strength ◽  
Experimental Design ◽  
Hot Mix Asphalt ◽  
Hydrated Lime ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Moisture Resistance ◽  
Strength Ratio ◽  
Moisture Susceptibility ◽  
Indirect Tensile

The objective of this study was to evaluate the effect of nano-sized hydrated lime on the moisture susceptibility of the hot mix asphalt (HMA) mixtures in terms of three methodologies to introduce into the mixtures. The experimental design for this study included the utilizations of one binder source (PG 64-22), three aggregate sources and three different methods introducing the lime. A total of 12 types of HMA mixtures and 72 specimens were fabricated and tested in this study. The performed properties include indirect tensile strength (ITS), tensile strength ratio (TSR), flow, and toughness. The results indicated that the nano-sized lime exhibits better moisture resistance. Introducing process of the nano-sized lime will produce difference in moisture susceptibility.

Numerical Simulation and Analysis on the Impact Effect of Cylindrical Projectile Impacting Shelled Explosive

2013 ◽  
Vol 710 ◽  
pp. 320-324
Author(s):  
Ying Zi Jiang ◽  
Wei Li Wang ◽  
Xue Feng Huang ◽  
Lei Fu ◽  
Zhuang Qing Fan
Keyword(s):  
Numerical Simulation ◽  
Energy Criterion ◽  
Critical Energy ◽  
Simplified Model ◽  
Initiation Point ◽  
4340 Steel ◽  
Simulation Results ◽  
The Impact ◽  
Explosive Detonation ◽  
Critical Initiation

The numerical simulation of shelled Comp.B explosive was studied following the Lee-Tarver ignition and growth model when it was impacted respectively by 4340 Steel, OFHC and 93#W projectile with the same mass; the influences on explosive detonation of the initiation process, the material of projectile and the L/D ratio of projectile were analyzed; the critical initiation speeds of the projectiles of three different materials with different L/D ratio were gained. In order to verify the simulation results, the questions were calculated by the theoretical simplified model, the results of the theoretical calculation and the numerical simulation accorded well based on critical energy criterion. The results show that the capability of igniting explosive, the first is 93#W, the second is OFHC, the last is 4340 Steel; The initiation point were not on the interface of shell and explosive, and the faster of the impacting velocity, the initiation point closer the interface; the bigger of the L/D ratio of projectile, the higher of the critical initiation speed.

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