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.

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.

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.

scholarly journals Laboratory Evaluation of the Use of Florida Washed Shell in Open-Graded Asphalt Mixtures

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7060
Author(s):  
Mohammad Alharthai ◽  
Qing Lu ◽  
Ahmed Elnihum ◽  
Asad Elmagarhe
Keyword(s):  
Tensile Strength ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Laboratory Evaluation ◽  
Void Content ◽  
Coarse Aggregates ◽  
Significant Difference ◽  
Indirect Tensile ◽  
Marshall Stability

This study investigates the substitution of conventional aggregate with a Florida washed shell in open-graded asphalt mixtures and evaluates the optimal substitution percentage in aggregate gradations of various nominal maximum aggregate sizes (NMASs) (i.e., 4.75, 9.5, and 12.5 mm). Laboratory experiments were performed on open-graded asphalt mixture specimens with the coarse aggregate of sizes between 2.36 and 12.5 mm being replaced by the Florida washed shell at various percentages (0, 15, 30, 45, and 100%). Specimen properties relevant to the performance of open-graded asphalt mixtures in the field were tested, evaluated, and compared. Specifically, a Marshall stability test, Cantabro test, indirect tensile strength test, air void content test, and permeability test were conducted to evaluate the strength, resistance to raveling, cracking resistance, void content, and permeability of open-graded asphalt mixtures. The results show that there is no significant difference in the Marshall stability and indirect tensile strength when the coarse aggregates are replaced with Florida washed shell. This study also found that the optimum percentages of Florida washed shell in open-graded asphalt mixture were 15, 30, and 45% for 12.5, 9.5, and 4.75 mm NMAS gradations, respectively.

scholarly journals Finite Element Analysis of the Multilayered Honeycomb Composite Material Subjected to Impact Loading

2017 ◽  
Vol 54 (1) ◽  
pp. 180-179 ◽  
Author(s):  
Raul Cormos ◽  
Horia Petrescu ◽  
Anton Hadar ◽  
Gorge Mihail Adir ◽  
Horia Gheorghiu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Material ◽  
Experimental Testing ◽  
Finite Element Models ◽  
The Finite Element Method ◽  
Low Velocity ◽  
Element Analysis ◽  
Element Simulation ◽  
Different Levels

The main purpose of this paper is the study the behavior of four multilayered composite material configurations subjected to different levels of low velocity impacts, in the linear elastc domain of the materials, using experimental testing and finite element simulation. The experimental results obtained after testing, are used to validate the finite element models of the four composite multilayered honeycomb structures, which makes possible the study, using only the finite element method, of these composite materials for a give application.

scholarly journals Integrating the Finite Element Method with a Data-Driven Approach for Dam Displacement Prediction

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Chenfei Shao ◽  
Chongshi Gu ◽  
Zhenzhu Meng ◽  
Yating Hu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Modulus ◽  
Random Coefficient ◽  
Arch Dam ◽  
Data Driven ◽  
The Finite Element Method ◽  
Random Coefficient Model ◽  
Proposed Model ◽  
Element Method

Both numerical simulations and data-driven methods have been applied in dam’s displacement modeling. For monitored displacement data-driven methods, the physical mechanism and structural correlations were rarely discussed. In order to take the spatial and temporal correlations among all monitoring points into account, we took the first step toward integrating the finite element method into a data-driven model. As the data-driven method, we selected the random coefficient model, which can make each explanatory variable coefficient of all monitoring points following one or several normal distributions. In this way, explanatory variables are constrained. Another contribution of the proposed model is that the actual elastic modulus at each monitoring point can be back-calculated. Moreover, with a Lagrange polynomial interpolation, we can obtain the distribution field of elastic modulus, rather than gaining one value for the whole dam in previous studies. The proposed model was validated by a case study of the concrete arch dam in Jinping-I hydropower station. It has a better prediction precision than the random coefficient model without the finite element method.

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