Evaluation of Variability in Resilient Modulus Test Results (ASTM D 4123)

1991 ◽  
Vol 19 (1) ◽  
pp. 1 ◽  
Author(s):  
A Wolfenden ◽  
ER Brown ◽  
KY Foo
Keyword(s):  
Resilient Modulus ◽  
Test Results

Study on Correction Method of Subgrade Modulus Based on FWD

2013 ◽  
Vol 579-580 ◽  
pp. 862-865
Author(s):  
Xiao Hua Luo ◽  
Qing Yang ◽  
Xin Qiu
Keyword(s):  
Resilient Modulus ◽  
Implementation Process ◽  
Correction Method ◽  
Deformation Analysis ◽  
Test Results ◽  
Moisture Condition ◽  
Back Calculation ◽  
The Mean ◽  
Subgrade Modulus ◽  
New Perspective

In order to calibrate subgrade back calculation modulus, the correction method of subgrade back calculation modulus was put forward based on theoretical analysis and indoor/outdoor experiments, and the detailed implementation process was analyzed combined the latest results of subgrade dynamic modulus and subgrade moisture forecast. The results show that the equivalent resilient modulus of subgrade simultaneously consider subgrade material moisture condition and stress dependency and the forecast equation has higher correlation. The ratio of the loading plate test results to the predicted results ranges from 0.25 to 0.4 and the mean is 0.32, which conforms to the requirements of AASHTO normal value. Utilizing the scale factor 0.65 to calibrate subgrade back calculation modulus is viable and validated. The results provides a new perspective and approach for deformation analysis of subgrade structure. As well, the established method makes up the defect that can't reflect the effect of moisture and stress on equivalent resilient modulus of subgrade.

Properties of Porous Asphalt Mixture Made with Styrene Butadiene Styrene under Long Term Oven Ageing

2012 ◽  
Vol 486 ◽  
pp. 378-383 ◽  
Author(s):  
Che Wan Che Norazman ◽  
Ramadhansyah Putra Jaya ◽  
Meor Othman Hamzah
Keyword(s):  
Resilient Modulus ◽  
Asphalt Mixture ◽  
Test Results ◽  
Air Voids ◽  
Porous Asphalt ◽  
Coefficient Of Permeability ◽  
Modified Binder ◽  
Styrene Butadiene ◽  
Butadiene Styrene

Oven ageing is a set of procedure to simulate the accelerated effects of ageing on pavements structures. In this study, the effect of long-term oven ageing on porous asphalt mixture made with SBS modified binder was investigated. The resilient modulus, water permeability and air voids test results were the performance indicators used to evaluate the effects of ageing. The test results showed that, the resilient modulus of long term aged specimens was higher than those of unaged specimens. From the permeability test results, unaged SBS mixes exhibit lower coefficient permeability compared to the corresponding long-term oven age specimens. Most likely, ageing caused binder hardening, making the mix more difficult to compact and hence exhibited more continuous voids which in turn lead to higher permeability. In addition, the coefficient of permeability decreases as the binder content increased.

scholarly journals Research on Intelligent Compaction Technology of Subgrade Based on Regression Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Ziyi Hou ◽  
Xiao Dang ◽  
Yezhen Yuan ◽  
Bo Tian ◽  
Sili Li
Keyword(s):  
Resilient Modulus ◽  
Single Point ◽  
Mean Value ◽  
Test Results ◽  
Intelligent Compaction ◽  
One Dimensional ◽  
Remote Monitoring System ◽  
The Mean ◽  
The One ◽  
Compaction Degree

A remote monitoring system with the intelligent compaction index CMV as the core is designed and developed to address the shortcomings of traditional subgrade compaction quality evaluation methods. Based on the actual project, the correlation between the CMV and conventional compaction indexes of compaction degree K and dynamic resilient modulus E is investigated by applying the one-dimensional linear regression equation for three types of subgrade fillers, clayey gravel, pulverized gravel, and soil-rock mixed fill, and the scheme of fitting CMV to the mean value of conventional indexes is adopted, which is compared with the scheme of fitting CMV to the single point of conventional indexes in the existing specification. The test results show that the correlation between the CMV and conventional indexes of clayey gravel and pulverized gravel is much stronger than that of soil-rock mixed subgrades, and the correlation coefficient can be significantly improved by fitting CMV to the mean of conventional indexes compared with single-point fitting, which can be considered as a new method for intelligent rolling correlation verification.

scholarly journals Experimental Study on the Effect of Compaction Work and Defect on the Strength of Soil-Rock Mixture Subgrade

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xin Yan ◽  
Wei Zhan ◽  
Zhi Hu ◽  
Yiqiang Yu ◽  
Danqiang Xiao
Keyword(s):  
Resilient Modulus ◽  
Good Condition ◽  
Stress Transfer ◽  
Loose Body ◽  
Earth Dam ◽  
Filling Material ◽  
Test Results ◽  
Engineering Characteristics ◽  
Modulus Of Resilience ◽  
Geotechnical Tests

Soil-rock mixture is a common filling material for earth dam and subgrade. In this study, research concerned on the evolution law of engineering characteristics of soil-rock mixture under different factors and the effect of defect on subgrade strength, and geotechnical tests were carried out to analyze the influence of different factors on engineering characteristics of soil-rock mixture in the study, and the physical model was carried out to analyze the effect of different compaction works on the resilient modulus, and the influence of defect on the strength was explored by manually preset loose body. The test results showed that (1) when the soil-rock mixture was graded, P = 78, the moisture content was 14%, and the engineering characteristics were optimal; (2) there was a positive correlation between compaction times and resilient modulus, and the stress transferred from the subgrade to soil was linearly distributed under the good condition of compactness; and (3) the existence of loose body not only reduces the modulus of resilience but also affects the stress transfer; the larger the loose body, the lower the resilient modulus and the greater the stress transfer.

Evaluation of Pyrolized Carbon Black from Scrap Tires as Additive in Hot Mix Asphalt

1996 ◽  
Vol 1530 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Taesoon Park ◽  
Brian J. Coree ◽  
C. W. Lovell
Keyword(s):  
Carbon Black ◽  
Asphalt Concrete ◽  
Resilient Modulus ◽  
Testing Machine ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Reinforcing Agent ◽  
Dynamic Creep ◽  
Temperature Susceptibility

The viability of using pyrolized carbon black (CBp) derived from waste tires as a reinforcing agent in asphalt mixtures was evaluated. Commercial carbon black (CB) has been previously shown to reduce the rutting resistance, temperature susceptibility, and cracking propagation potential of asphalt concrete. It was believed that CBp could produce similar benefits; this belief has been confirmed by this study. Different ratios of CBp and CB (5, 10, 15, and 20 percent by weight of asphalt) were blended with two grades of asphalt (AC-10 and AC-20). The Marshall method, the gyratory testing machine, the dynamic creep testing (confined), the indirect tensile testing, and the resilient modulus test were performed. The test results of CBp mixtures were compared with results of CB and conventional mixtures. The analyses of test results show that the typical performance of CBp-modified asphalt mixtures is improved with respect to commercial CB and conventional mixtures. The rutting potential and the temperature susceptibility can be reduced by the inclusion of CBp in the asphalt mixture. A CBp content of 10 to 15 percent by weight of asphalt is recommended for improvement of asphalt concrete.

scholarly journals Mechanics and Pavement Properties Research of Nanomaterial Modified Asphalt

2012 ◽  
Vol 5 ◽  
pp. 259-264 ◽  
Author(s):  
Shang Jiang Chen ◽  
Xiao Ning Zhang
Keyword(s):  
Low Temperature ◽  
Resilient Modulus ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Test Results ◽  
Modified Asphalt ◽  
Cleavage Strength ◽  
Modified Asphalt Binder ◽  
Powdered Rubber ◽  
Temperature Crack

Nanomaterials (nano powdered rubber VP401, VP501 and sepiolite and CaCo3 composites) were selected to improve the high-temperature and low-temperature performance of asphalt binder. Nanomaterial modified asphalt was prepared using the high shear machine. Laboratory experiments of asphalt binder and asphalt mixture were conducted to evaluate the properties of modified asphalt binder, including the penetration, ductility, softening point, viscosity, and etc. Also, asphalt mixture tests were carried out, such as the cleavage strength test, resilient modulus test, rutting test, water stability test and etc. Based on the test results, asphalt binder modified by 1% nano powdered rubber VP401 has better performance resistance to low temperature crack and rutting, compared to other nanomaterial modified asphalt binder.

Relationship Between Backcalculated and Laboratory-Measured Resilient Moduli of Unbound Materials

2003 ◽  
Vol 1849 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Gerardo W. Flintsch ◽  
Imad L. Al-Qadi ◽  
Youngjin Park ◽  
Thomas L. Brandon ◽  
Alexander Appea
Keyword(s):  
Resilient Modulus ◽  
Shift Factor ◽  
Falling Weight Deflectometer ◽  
Test Results ◽  
Structural Capacity ◽  
Bulk Stress ◽  
Stress Dependent ◽  
Falling Weight ◽  
Virginia Smart Road

The resilient moduli of an unbound granular subbase (used at the Virginia Smart Road) obtained from laboratory testing were compared with those backcalculated from in situ falling weight deflectometer deflection measurements. Testing was performed on the surface of the finished subgrade and granular subbase layer shortly after construction. The structural capacity of the constructed subgrade and the depth to a stiff layer were computed for 12 experimental sections. The in situ resilient modulus of the granular subbase layer (21-B) was then back-calculated from the deflections measured on top of that layer. The back-calculated layer moduli were clearly stress-dependent, showing an exponential behavior with the bulk stress in the center of the layer. Resilient modulus test results of laboratory-compacted specimens confirmed the stress dependence of the subbase material modulus. Three resilient modulus models were fitted to the data. Although all three models showed good coefficients of determination ( R2 > 90%), the K-θ model was selected because of its simplicity. The correlation between field-backcalculated and laboratory-measured resilient moduli was found to be strong. However, when the stress in the middle of the layer was used in the K-θ model, a shift in the resilient modulus, θ, was observed. This finding suggests that a simple shift factor could be used for the range of stress values considered.

scholarly journals Resilient Response of Cement-Treated Coarse Post-Glacial Soil to Cyclic Load

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6495
Author(s):  
Katarzyna Zabielska-Adamska ◽  
Mariola Wasil ◽  
Patryk Dobrzycki
Keyword(s):  
Resilient Modulus ◽  
Axial Strain ◽  
Coarse Grained ◽  
Curing Time ◽  
Test Results ◽  
The Road ◽  
Compaction Energy ◽  
Load Sequence ◽  
Resilient Response ◽  
Compaction Method

Stabilisation with cement is an effective way to increase the stiffness of base and subbase layers and to improve the rutting of subgrade. The aim of the study is to investigate the effect of different percentages of cement additives (1.5%, 3.0%, 4.5% and 6.0%) on the resilient modulus of coarse-grained soil used on road foundations. The influence of the compaction method, the standard Proctor and the modified Proctor, as well as the sample curing time is analysed. The cement addition significantly increases the resilient modulus and reduces the resilient axial strain. Extending the curing time from 7 to 28 days also improves the resilient modulus. The change in the compaction energy from standard to modified does not increase the resilient modulus of the stabilised gravelly sand due to its compaction characteristics. The test results of the resilient modulus of the gravelly sand stabilised with cement indicate the possibility of using it as a material for the road base and subbase due to meeting the AASHTO requirements. However, the non-stabilised gravelly sand does not meet the above requirements. It has been sheared during cyclic tests at the first load sequence, regardless of the compaction method.

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