Effects of state of test sample, specimen geometry and sample preparation on dynamic properties of rubber–sand mixtures. Issue 4 (April 2015)

• Record Type: Journal Article
• Authors: Senetakis, K.; Anastasiadis, A.
• Is Part Of: Geosynthetics international. Volume 22:Issue 4(2015)
• Page Start: 301
• Page End: 310
• Publication Date: 2015-04
• Subjects: Geosynthetics -- Granulated rubber -- Sand–rubber mixtures -- Shear modulus -- Damping ratio -- Resonant column; Geosynthetics -- Periodicals; Geosynthetics; Periodicals; 624.1892
• DOI: 10.1680/gein.15.00013
• Languages: English
• ISSNs: 1072-6349

Abstract

Abstract : ABSTRACT: The study presents resonant column test results on sand mixed with granulated rubber. The experiments were carried out on samples within a range of rubber content from 0 to 15% by dry weight of sand–rubber mixtures, at variable isotropic effective stresses, p ′, state of test sample and sample preparation method. Both small-diameter specimens of 36 mm × 82 mm in size and large-diameter samples of about 70 mm × 140 mm in size were tested in torsional mode of vibration at very small shear strain amplitudes, in general less than 10 −5 . Specimens were tested in a dry state, a moist state with a very small water content inclusion and a fully saturated state. The data indicated that for a given p ′, the increase of rubber content shifted the obtained resonant frequencies to lower values, the small-strain shear modulus, G 0, decreased, whereas small-strain material damping, D s0, increased. The state of test sample, namely dry, moist or fully saturated, did not affect the obtained small-strain shear modulus values but did affect the obtained D s0 . G 0 could efficiently be described through typical formulas of G 0 against p ′ used for sands, by treating the volume of rubber particles as part of the total volume of voids into the void ratio function of the G 0 – p ′ relationship. By preparing the samples at variable initial void ratios, comparisons could be obtained between samples of variable rubber contents and state of test sample but at a given resonant frequency. This is very important in capturing the behaviour of the mixtures in resonant column test which is a non-frequency-controlled method and thus the effect of rubber content and loading frequency could be de-coupled in the experiments.