Resilient Modulus of Freeze - Thaw Affected Granular Soils for Pavement Design and Evaluation, Part 1: Laboratory Tests on Soils from Winchendon, Massachusetts, Test Sections

Resilient Modulus of Freeze - Thaw Affected Granular Soils for Pavement Design and Evaluation, Part 1: Laboratory Tests on Soils from Winchendon, Massachusetts, Test Sections
Author: Cold Regions Research and Engineering Laboratory (U.S.)
Publisher:
Total Pages: 70
Release: 1986
Genre:
ISBN:

This work is the first of a series of four reports about laboratory and field testing of various granular road and airfield subgrades. This report details the acquisition, testing and analysis of six soils from a test site in Winchendon, Massachusetts. Repeated load triaxial tests were done on frozen and thawed soils to characterize the variations in their resilient properties through out the seasons. Linear regression yielded empirical equations relating the resilient modulus to applied stress, unfrozen water content (for frozen soils), moisture tension (for thawed soils) and density. Equipment and test procedures (given in detail) were developed that allowed simulation in the laboratory of the gradual recovery of stiffness that occurs in the field after thawing. The resilient moduli were strongly dependent on soil state, dropping at least two orders of magnitude upon thawing. For all soils the moduli increased with increasing confining stress, generally decreased with increasing principal stress ratio, and increased with increasing moisture tension levels. The resilient moduli increased by a factor of approximately two as the materials recovered from the effects of a freeze-thaw cycle. This recovery process is well modeled as a function of soil moisture tension level. The stress sensitivity did not appear to be a function of the soil moisture tension level. The report also includes tabulations of all the repeated load triaxial test data.

Determination of Resilient Modulus Values for Typical Plastic Soils in Wisconsin

Determination of Resilient Modulus Values for Typical Plastic Soils in Wisconsin
Author: Hani Hasan Titi
Publisher:
Total Pages: 316
Release: 2011
Genre: Pavements
ISBN:

The objectives of this research are to establish a resilient modulus test results database and to develop correlations for estimating the resilient modulus of Wisconsin fine-grained soils from basic soil properties. A laboratory testing program was conducted on representative Wisconsin fine-grained soils to evaluate their physical and compaction properties. The resilient modulus of the investigated soils was determined from the repeated load triaxial (RLT) test following the AASHTO T307 procedure. The laboratory testing program produced a high-quality and consistent test results database.

Resilient and Permanent Characteristics of Reinforced Granular Materials by Repeated Load Triaxial Tests

Resilient and Permanent Characteristics of Reinforced Granular Materials by Repeated Load Triaxial Tests
Author: F. Moghaddas-Nejad
Publisher:
Total Pages: 15
Release: 2003
Genre: Geogrid
ISBN:

Drained repeated load triaxial compression tests were conducted to investigate the resilient and permanent stress-strain behavior of two granular materials reinforced by a geogrid. In order to obtain more accurate measurement of recoverable deformation, an on-sample measuring method was utilized. Because devices for measuring the axial and lateral deformation are attached to the specimen, the confining pressure is provided by applying a vacuum within the specimen. The effect of a geogrid in reducing the permanent deformation of soils at various combinations of deviator and confining stress is investigated and discussed. The test results indicate that a geogrid can play a significant role in reduction of deformation of the triaxial specimen, and could, therefore, be expected to reduce deformations in the field. However, the results obtained for resilient deformations show that the geogrid does not have a considerable influence on the resilient modulus of the two types of soil (sand and fine gravel) that were tested.

Resilient Modulus of Freeze-Thaw Affected Granular Soils for Pavement Design and Evaluation. Part 3. Laboratory Tests on Soils from Albany County Airport

Resilient Modulus of Freeze-Thaw Affected Granular Soils for Pavement Design and Evaluation. Part 3. Laboratory Tests on Soils from Albany County Airport
Author: David M. Cole
Publisher:
Total Pages: 40
Release: 1987
Genre:
ISBN:

This is the third in a series of four reports on the laboratory and field testing of a number of road and airfield subgrades, covering the laboratory repeated-load triaxial testing of five soils in the frozen and thawed states and analysis of the resulting resilient modulus measurements. The laboratory testing procedures allow simulation of the gradual increase in stiffness found in frost-susceptible soils after thawing. The resilient modulus is expressed in a nonlinear model in terms of the applied stresses, the soil moisture tension level (for unfrozen soil), the unfrozen water content (for frozen soil) and the dry density. The resilient modulus is about 10 GPa for the frozen material at temperatures in the range of -5 to -8 C. The decrease in modulus with increasing temperatures was well-modeled in terms of the unfrozen water content. Upon thaw, the modulus dropped to about 100 MPa and generally increased with increasing confining stress and decreased with increasing principal stress ratio. The modulus also increased with the soil moisture tension level. The resilient Poisson's ratio did not appear to be a systematic function of any of the test variables. Keywords: Soil dynamics; Soil stabilization.