The Use of a Vibratory Compactor on Granular Base Courses

2009 ◽  
pp. 67-67-8
Author(s):  
C. R. White
Keyword(s):  
Granular Base

Mechanistic Comparison of Cement- and Bituminous-Stabilized Granular Base Systems

2007 ◽  
Vol 2026 (1) ◽  
pp. 70-80 ◽  
Author(s):  
Curtis Berthelot ◽  
Brent Marjerison ◽  
Gary Houston ◽  
Jody McCaig ◽  
Stu Warrener ◽  
...  
Keyword(s):  
Granular Base

Successful Application of Ground-Penetrating Radar for Quality Assurance-Quality Control of New Pavements

2003 ◽  
Vol 1861 (1) ◽  
pp. 86-97 ◽  
Author(s):  
Imad L. Al-Qadi ◽  
Samer Lahouar ◽  
Amara Loulizi
Keyword(s):  
Quality Control ◽  
Quality Assurance ◽  
Ground Penetrating Radar ◽  
Test Section ◽  
Base Layer ◽  
Quality Control Tool ◽  
Granular Base ◽  
The One ◽  
The Time Domain ◽  
Ground Penetrating

The successful application of ground-penetrating radar (GPR) as a quality assurance–quality control tool to measure the layer thicknesses of newly built pavement systems is described. A study was conducted on a newly built test section of Route 288 located near Richmond, Virginia. The test section is a three-lane, 370-m-long flexible pavement system composed of a granular base layer and three different hot-mix asphalt (HMA) lifts. GPR surveys were conducted on each lift of the HMA layers after they were constructed. To estimate the layer thicknesses, GPR data were analyzed by using simplified equations in the time domain. The accuracies of the GPR system results were checked by comparing the thicknesses predicted with the GPR to the thicknesses measured directly from a large number of cores taken from the different HMA lifts. This comparison revealed a mean thickness error of 2.9% for HMA layers ranging in thickness from 100 mm (4 in.) to 250 mm (10 in.). This error is similar to the one obtained from the direct measurement of core thickness.

Moisture Accumulation and Pore Water Pressures at Base of Pavements

1996 ◽  
Vol 1546 (1) ◽  
pp. 151-161 ◽  
Author(s):  
K. D. Eigenbrod ◽  
G. J. A. Kennepohl
Keyword(s):  
Pore Water ◽  
Base Material ◽  
The United States ◽  
Base Layer ◽  
Frozen Ground ◽  
Extensive Field ◽  
Pore Water Pressures ◽  
Excess Moisture ◽  
Pavement Base ◽  
Granular Base

A unique mechanism based on extensive field and laboratory studies is presented to account for certain premature failures of flexible pavements in cold areas like those in Scandinavia and in northern parts of Canada and the United States. Water condensing at the interface between pavement and granular base accumulates at subzero temperatures resulting in excess moisture in this zone. During the thaw period of the uppermost base layer, the excess water in the aggregate is trapped between impervious layers of frozen ground to the sides and below as well as an impervious layer of asphalt pavement above. Because of this containment, high pore water pressures can occur, leading to loss in shear strength of the base material and thus to failure of the pavement structure itself. It was found that under special conditions, excess moisture can accumulate in granular base with a silt content greater than 20 percent and very high pore water pressures can develop during initial thaw at the pavement-soil interface. With silt contents of less than 2 percent, excess pore water pressures can be avoided during thaw. It was also shown that when a clean open gravel is placed below the pavement on top of a silty base material, moisture accumulation near the pavement-base interface can be prevented, and thus also the development of high pore water pressures.

Influence of relative density of the granular base soil on filter performance

2020 ◽  
Vol 15 (12) ◽  
pp. 3621-3627
Author(s):  
Peter To ◽  
Daniel Agius ◽  
Liam Cussen
Keyword(s):  
Relative Density ◽  
Filter Performance ◽  
Granular Base ◽  
Base Soil

scholarly journals Prediction Model of Elastic Modulus for Granular Road Bases

2020 ◽  
Vol 2 (1) ◽  
pp. p35
Author(s):  
Zainab Ahmed Alkaissi ◽  
Hassan Adnan
Keyword(s):  
Elastic Modulus ◽  
Linear Regression Analysis ◽  
Base Material ◽  
Recycled Concrete ◽  
Dry Density ◽  
Concrete Aggregate ◽  
Vertical Loading ◽  
Base Materials ◽  
Granular Base ◽  
Road Bases

The estimation of elastic modulus for road bases is the primary objective of this research which is implemented a significant role in transmitting the vertical loading to the pavement foundation layers. In this study, the effect of weathering conditions on the stiffness of base course is investigated and implied the durability test by subjecting the prepared samples to a different numbers of wet-dry cycles (0,2, 4, 6, 8 and 10). A conventional base materials of local natural gravel aggregate and treated base materials with recycled concrete aggregate RCA at different percentages (0%, 25%, 50% 75% and 100%) is adopted in this research. The elastic characteristics are estimated in terms of elastic modulus. Elastic modulus are estimated by passing the ultrasonic pulse velocity through the untreated and treated base materials laboratory specimens. This test can be used to study the elastic modulus properties of base materials. A multiple linear regression analysis is used for prediction the elastic modulus using the SPSS (software ver.21). Elastic Modulus (kPa) is the dependent variable whereas the independent variable are; No. of wet- dry cycle and Percent (%) of RCA stabilizer. The obtained results for elastic modulus (Es) of granular base material layer showed increasing in elastic modulus with percentage of RCA%., results revealed that the (Es) values reached a maximum value of (6927kPa) for 100%. For the OMC’s values increases due to the percentage increment of RCA in granular base material mixture, this increment in water contents is refer to high absorption capacity of the paste clinging to the RCA. On other side the dry density decrease gradually with adding percentage of (RCA) in granular base material mixture.

scholarly journals EFFECTS OF FREEZE-THAWING ON BEARING CAPACITY OF GRANULAR BASE COURSE MATERIAL

2012 ◽  
Vol 68 (3) ◽  
pp. I_115-I_122
Author(s):  
Shinichiro KAWABATA ◽  
Tatsuya ISHIKAWA ◽  
Takumi MURAYAMA ◽  
Shuichi KAMEYAMA
Keyword(s):  
Bearing Capacity ◽  
Base Course Material ◽  
Course Material ◽  
Base Course ◽  
Granular Base

scholarly journals Modeling Stress-Dependent Anisotropic Elastoplastic Unbound Granular Base in Flexible Pavements

2018 ◽  
Vol 2672 (52) ◽  
pp. 46-56 ◽  
Author(s):  
Yuqing Zhang ◽  
Fan Gu ◽  
Xue Luo ◽  
Bjorn Birgisson ◽  
Robert L. Lytton
Keyword(s):  
Stress Responses ◽  
Compressive Strain ◽  
Flexible Pavements ◽  
Plastic Behavior ◽  
Elastic Model ◽  
Nonlinear Stress ◽  
Anisotropic Elastic ◽  
Base Course ◽  
Granular Base ◽  
Stress Dependent

Unbound granular base (UGB) has a cross-anisotropic and nonlinear (stress-dependent) modulus with a plastic behavior. Existing UGB models address nonlinear cross-anisotropy and plasticity separately. It is unknown how the two characteristics are coupled into a finite element model (FEM) and how this will affect the pavement responses. This study presents a coupled nonlinear cross-anisotropic elastoplastic (NAEP) constitutive model for the UGB and implements it in a weak form equation-based FEM. No material subroutine is needed to address the circular dependence between the stress-dependent anisotropic modulus, structural stress responses, and elastoplastic deformation. The NAEP model was calibrated by triaxial resilient modulus and strength tests and validated using laboratory measurements in a large-scale soil-tank pavement structural test. It is found that the NAEP model is valid and effective in predicting the UGB responses in flexible pavements. The model predicted less horizontal tensile stresses at the base bottom and introduced compressive stresses in the middle and top of the base course. This is caused by an increasing confinement resulting from a horizontal plastic dilation in the base course, which cannot be modeled without considering plasticity. The stress-dependent modulus for the UGB material decreases with depth and the distance from loading centerline. Compared with a nonlinear anisotropic elastic model, the NAEP model predicted the same tensile strain at asphalt layer bottom, a higher base modulus, and a higher subgrade compressive strain. Thus, the nonlinear anisotropic elastic UGB model results in the same fatigue life as the NAEP model but may riskily under-predict rutting damage.

scholarly journals Effects of Freeze-thaw History on Bearing Capacity of Granular Base Course Materials

2016 ◽  
Vol 143 ◽  
pp. 828-835 ◽  
Author(s):  
Shinichiro Kawabata ◽  
Tatsuya Ishikawa ◽  
Shuichi Kameyama
Keyword(s):  
Bearing Capacity ◽  
Freeze Thaw ◽  
Course Materials ◽  
Base Course ◽  
Granular Base
Sign in / Sign up

Export Citation Format

Share Document