REINFORCEMENT OF SAND WITH SHREDDED WASTE TIRES BY SUMAN ROY
Oct 22, 2014
REINFORCEMENT OF SAND WITH
SHREDDED WASTE TIRES
BY SUMAN ROY
A LARGE AMOUNT OF TIRES ARE DISPOSED
OF EVERY YEAR.
IN ORDER TO AVOID STOCKPILES, TIRES ARE
USED AS A RECYCLING MATERIAL.
WASTE TIRES ARE USED TO ENHANCE SHEAR
STRENGTH OF SOIL.
SHREDDED WASTE TIRES ARE NOW USED AS
CONSTRUCTION MATERIAL.
SUB GRADE REINFORCEMENT
AS SOUND BARRIERS
TRUCK BED LINERS, DOORMATS, AND CUSHIONING
FOAMS
OBJECTIVE OF TEST:
FEASIBILITY OF USING SHREDDED WASTE
TIRES TO REINFORCE SAND.
OBJECTIVE OF TEST:
FEASIBILITY OF USING SHREDDED WASTE
TIRES TO REINFORCE SAND.
SAND USED:
DRY PORTAGE SAND
PROPERTIES OF PORTAGE SAND USED COEFFICIENT OF UNIFORMITY OF 1.0
A COEFFICIENT OF CURVATURE OF
1.0
SPECIFIC GRAVITY OF 2.68.
THE MINIMUM UNIT WEIGHT
OF THE SAND IS 15.5 kN/M3 AND THE
MAXIMUM UNIT WEIGHT IS
17.7 kN/M3
PEAK FRICTION ANGLE OF 25°WHEN
ITS UNIT WEIGHT IS 15.5 kN/M3
AND 34° WHEN ITS UNIT WEIGHT IS
17.7 kN/M3
PROPERTIES OF SHREDDED TIRES USED
DIVIDED IN THREE GROUPS:
5 CM
10 CM
15 CM
DIRECT SHEAR MACHINE
STAINLESS STEEL SHEAR RINGS
INSIDE DIAMETER =27.9 CM
TOP AND BOTTOM HALVES OF THE SHEAR RING
HEIGHT =15.7 CM .
RATE OF DISPLACEMENT =0.13 CM/MIN.
A COMPUTERIZED DATA ACQUISITION SYSTEM
WAS USED TO RECORD THE DATA.
PREPARATION OF SPECIMEN
ONE-FOURTH OF THE TIRE SHREDS NEEDED TO
ATTAIN THE DESIRED TIRE SHRED CONTENT WERE
INITIALLY HAND PLACED IN THE BOTTOM OF THE
RING.
PREPARATION OF SPECIMEN
ONE-FOURTH OF THE TIRE SHREDS NEEDED TO
ATTAIN THE DESIRED TIRE SHRED CONTENT WERE
INITIALLY HAND PLACED IN THE BOTTOM OF THE
RING.
SAND WAS RAINED INTO THE SHEAR RING ON TOP
OF THE SHREDS IN A CIRCULAR MOTION
PREPARATION OF SPECIMEN
ONE-FOURTH OF THE TIRE SHREDS NEEDED TO
ATTAIN THE DESIRED TIRE SHRED CONTENT WERE
INITIALLY HAND PLACED IN THE BOTTOM OF THE
RING.
SAND WAS RAINED INTO THE SHEAR RING ON TOP
OF THE SHREDS IN A CIRCULAR MOTION
THE SPECIMENS WERE THEN VIBRATED ON A
VIBRATING TABLE UNTIL THE DESIRED SAND MATRIX
UNIT WEIGHT WAS OBTAINED.
FACTORS TAKEN UNDER CONSIDERATION
NORMAL STRESS
SAND MATRIX UNIT WEIGHT
SHRED CONTENT
SHRED LENGTH
SHRED ORIENTATION
NON LINEARITY OF STRENGTH ENVELOPE
VOLUME CHANGE
WHICH FACTORS AFFECTED MOST?
NORMAL STRESS
SHRED CONTENT
SAND MATRIX UNIT WEIGHT
This was found out by YATE’S ALGORITHM
which is a common method for predicting
the factors affecting a test
In this case efficiency of 95% was targeted.
It utilizes t statistics and an aim for t value
greater than 2.262 was targeted.
t distribution
SHRED CONTENT
SAND MATRIX UNIT WEIGHT
A TEST ON TIRE SHREDS ONLY
HIGHER FRICTION ANGLES WERE ALSO
OBSERVED.
ANGLE OF REPOSE OF 45O AND 850 WAS
OBSERVED IN SOME CASES.
WHY THERE IS AN INCREASE IN SHEAR STRENGTH ?
∆S = increase in shear strength of soil
Ar = area of reinforcements
A = area of shear zone
θ = angle of shear distortion = tan-1 (x/z)
φ = angle of internal friction for soil
σt = tensile stress in fiber
However it can also be modified by a model where
tire shreds are assumed to behave as fibers
This is known as Maher and Gray's (1990) model
It includes several other assumptions.
Based on this model value of predicted φ1’ was found
to be closer to the actual value in experiment
SUMMARY
THE SHEAR STRENGTH OF SAND-TIRE SHRED MIXTURES WAS
INVESTIGATED IN THIS STUDY.
THREE FACTORS WERE FOUND TO SIGNIFICANTLY AFFECT
THEIR SHEAR STRENGTH: NORMAL STRESS, SHRED CONTENT,
AND SAND MATRIX UNIT WEIGHT.
FURTHERMORE, IN ALL CASES, SAND CONTAINING SHREDDED
TIRES HAD HIGHER SHEAR STRENGTH THAN SAND ALONE.
STRENGTH ENVELOPES FOR MIXTURES CONTAINING DENSE
SAND ARE NONLINEAR.
INITIAL FRICTION ANGLES AS LARGE AS 67° WERE
OBTAINED WHEN THE SAND MATRIX WAS DENSE.
THE FRICTION ANGLE FOR UNREINFORCED PORTAGE SAND
AT THE SAME UNIT WEIGHT IS 34°.
THE INITIAL FRICTION ANGLE INCREASED AS THE SHRED
CONTENT WAS INCREASED.
SAND MATRIX UNIT WEIGHT IS AN IMPORTANT PARAMETER
AFFECTING THE INITIAL FRICTION ANGLE.
REFERENCES Bosscher, P. J., Edil, T. B., and Eldin, N. (1993). "Construction and
performance of shredded waste tire test embankment." Transp. Res.Rec.•
No. 1345, Transp. Res. Board, Washington, D.C., 44-52.
Box, G., Hunter, W., and Hunter, J. (1978). Statistics for
experimenters.Wiley-Interscience, New York, N.Y.
DEFORMATION CHARACTERISTICS OF REINFORCEDSAND IN DIRECT SHEAR
By Scott E. Shewbridge and Nicholas Sitar, Associate Members, ASCE
SAND REINFORCED WITH SHREDDED WASTE TIRES By Gary J. Foose,Craig H.
Benson and Peter J. Bosscher Members, ASCE
Foose. G. (1993). "Shear strength of sand reinforced with shredded waste
tires," MSc thesis, Dept. ofCiv. and Envir. Engrg., Univ. of Wisconsin
Madison,Wis.
Gray, D., and AI-Refeai, T. (1986). "Behavior of fabric-versus fiber reinforced
sand." J. Geotech. Engrg.• ASCE, 112(8), 804-820
THANK YOU