Dynamic Modulus and Fatigue Testing of Lightly Cementitiously Stabilized Granular Pavement Materials

2008 ◽  
Author(s):  
Piratheepan Jegatheesan ◽  
C. T. Gnanendran
Keyword(s):  
Dynamic Modulus ◽  
Fatigue Testing ◽  
Pavement Materials

Optimization of the Laboratory Fabrication of Small Specimens for Asphalt Mixture Performance Testing

2018 ◽  
Vol 2672 (28) ◽  
pp. 438-450 ◽  
Author(s):  
Sonja Pape ◽  
Kangjin Lee ◽  
Cassie Castorena ◽  
Y. Richard Kim
Keyword(s):  
Dynamic Modulus ◽  
Fatigue Testing ◽  
Extraction Procedure ◽  
Asphalt Mixture ◽  
Performance Testing ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Void Content ◽  
Multiple Test ◽  
Air Void

The use of 38-mm-diameter small specimens for uniaxial dynamic modulus and cyclic fatigue asphalt mixture performance testing offers a significant opportunity to improve the efficiency of laboratory-fabricated specimen testing because multiple test specimens can be extracted per Superpave gyratory-compacted (SGC) sample. This study seeks to optimize the procedure used for the extraction of small specimens from SGC samples for dynamic modulus and cyclic fatigue tests. To this end, small cylindrical specimens were cored horizontally and vertically from SGC samples and subjected to performance testing. The dynamic modulus and fatigue test results indicate that the effects of anisotropy are minimal. However, all of the horizontally extracted small specimens exhibited fatigue failure at the specimen ends, outside the range of the gauges; the failure was likely due to the peripheral air void gradients in the SGC samples. Therefore, the authors concluded that small specimens should be vertically cored from SGC samples for the laboratory fabrication of small specimens. Specifically, four small specimens were cored vertically from the inner 100 mm of SGC samples where the air void content is relatively uniform. Four mixtures with different nominal maximum aggregate sizes (NMASs) were used to prepare small specimens using the proposed extraction procedure. These specimens were subjected to dynamic modulus and cyclic fatigue testing. The results demonstrate an increase in specimen-to-specimen variability with an increase in NMAS, which also is expected in large specimen testing.

Effect of Asphalt Mixture Components on the Uncertainty in Dynamic Modulus Mastercurves

2020 ◽  
Vol 2674 (5) ◽  
pp. 135-148
Author(s):  
Hussein Kassem ◽  
Ghassan Chehab ◽  
Shadi Najjar
Keyword(s):  
Dynamic Modulus ◽  
Asphalt Mixture ◽  
Fundamental Property ◽  
Aggregate Size ◽  
Pavement Design ◽  
Experimental Program ◽  
Maximum Aggregate Size ◽  
Pavement Materials ◽  
Material Sources ◽  
Key Factor

Practitioners and researchers in the paving industry have highlighted the importance of the adoption of reliability-based pavement design. The goal of developing reliable pavements with optimum performance over their design life has become a key factor to be considered during both pavement design and construction processes. This requires the adoption of statistical and probabilistic-based analyses for the formulation of the properties and behavior of pavement materials. Thus, many researchers worked on the quantification and modeling of the uncertainty caused by the inherent variability in pavement materials in general and that of asphalt concrete (AC) in particular. The dynamic modulus (| E*|), a fundamental property for mechanistic-empirical and purely mechanistic pavement designs, has been proven to have a significant level of uncertainty that is dependent on climatic and traffic loading conditions. The main objective of this study is to investigate the effect of the AC mixture properties and components on the uncertainty in the | E*| mastercurve. This objective is achieved by conducting an experimental program incorporating four different mixtures having the same material sources but different binder types and gradations. Monte Carlo simulations are used to model the uncertainty of | E*| for each of these mixtures. The paper shows that the uncertainty is dependent on mixture type, as the presence of larger nominal maximum aggregate size, modified binder, or additive can increase the uncertainty in the | E*| mastercurve, especially at high temperatures or slow loading rates. The uncertainty is proven to be material related and not imposed by the testing instrumentation.

Fatigue of Unidirectional Cord-Rubber Composites

1999 ◽  
Vol 27 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Y. Liu ◽  
Z. Wan ◽  
Z. Tian ◽  
X. Du ◽  
J. Jiang ◽  
...  
Keyword(s):  
Damage Accumulation ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Constant Load ◽  
Testing System ◽  
Rubber Composites ◽  
Cycle Frequency ◽  
Periodic Loading ◽  
Fatigue Damage Accumulation ◽  
Rubber Composite

Abstract A fatigue testing system is established with which the real-time recording of stress, strain, temperature, and hysteresis loss of rubbers or cord-rubber composite specimens subjected to periodic loading or extension can be successfully carried out. Several problems are connected with the experimental study of the fatigue of rubber composites. In constant extension cycling, the specimen becomes relaxed because of the viscoelasticity of rubber composites, and the imposed tension-tension deformation becomes complex. In this method, the specimen is unlikely to fail unless the imposed extensions are very large. Constant load cycling can avoid the shortcomings of constant extension cycling. The specially designed clamps ensure that the specimen does not slip when the load retains a constant value. The Deformation and fatigue damage accumulation processes of rubber composites under periodic loading are also examined. Obviously, the effect of cycle frequency on the fatigue life of rubber composites can not be ignored because of the viscoelasticity of constituent materials. The increase of specimen surface temperature is relatively small in the case of 1 Hz, but the temperature can easily reach 100°C at the 8 Hz frequency. A method for evaluating the fatigue behavior of tires is proposed.

On a New Rotating Bending Fatigue Testing Machine

1966 ◽  
Vol 15 (148) ◽  
pp. 49-54
Author(s):  
Minoru KAWAMOTO ◽  
Katsumi SUMIHIRO ◽  
Koji KIDA
Keyword(s):  
Fatigue Testing ◽  
Testing Machine ◽  
Bending Fatigue ◽  
Rotating Bending Fatigue ◽  
Rotating Bending
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