Aashto T307
Aashto T307
Aashto T307
and
Twentieth Edition
2000
PART II TESTS
by the
Adopted
StandardMethod of Test
for
1084
rial Type 2 includes all untreatedgranu- p max = P contact+ P cyclic 3.11 Cyclic Axial Stress (Resilient
lar base/subbaseand untreated subgrade
Stress,ScyclicJ-Cyclic (resilient) applied
soils not meeting the criteria for material 3.8 Contact Load (P contact)-Verti- axial stress.
Type 1 given above in 3.3. Thin-walled calload placed on the specimento main-
tube samples of untreated subgradesoils tain a positive contact betweenthe speci- Scyclic = P cyclic I A
fall in this Type 2 category. men cap and the specimen.
3.12 ContactStress (Scontac,}-Axial
3.5 Resilient Modulus of Untreated
Pcontact= O.lPmax
stressapplied to a test specimento main-
Materials-The modulus of an untreated tain a positive contact between the speci-
material is determined by repeatedload men cap and the specimen.
triaxial compressiontests on test speci- 3.9 Cyclic Axial Load (Resilient Ver-
mens of the untreated material samples. tical Load, PcyclicJ-Repetitive load ap- Scontact= P contactI A
Resilient modulus (MJ is the ratio of plied to a test specimen.
Also,
the amplitude of the repeatedaxial stress
P cyclic = P max -P cOntact SCOnlaC!
= O.lSmax
to the amplitude of the resultantrecover-
able axial strain. 3.13 S3is the total radial stress; that
3.10 Maximum Applied Axial Stress
3.6 Haversine-ShapedLoad Fonn- is, the applied confming pressure in the
(SmaJ-The total stress applied to the
The required load pulse form. The load triaxial chamber(minor principal stress).
sample,including the contact stressand
pulse is in the form (I-cos 6) / 2 as the cyclic (resilient) stress.
shown in Figure 1. 3.14 er is the resilient (recovered)
3.7 Maximum Applied Axial Load Smax = PmaxI A axial deformation due to Scyclic.
(P max)- The total load applied to the 3.15 Er is the resilient (recovered)
sample, including the contact and cyclic where: A = initial cross-sectionalarea axial strain due to Scyclic'
(resilient) loads. of the specimen
Er=e./L
where L = original specimen length.
4. Summaryof Method
5. Significanceand Use
*The rest period will be 0.9s for hydraulic loading
devicesand 0.9 to 3.0 s for pneumaticloadingdevices. 5.1 The resilient modulus test pro-
vides a basic relationship between stress
FIGURE1 Definition of ResilientModulusTerms and deformation of pavement materials
1086 METHODS OF SAMPLING AND TESTING T307
REPEATED
LOADACTUATOR
6.2.1 The haversine-shapedload
pulse shall confonn to Section 3.6. All
.DAD CELL preconditioning and testing shall be con-
-BAll SEAT(DrJDT)
ducted using a haversine-shaped load
CHAMBER PISTONROD
13mmMINDIA FOR ~STEEl BAll pulse. The system-generated
haversine
TYPE2 SOILS 51 mmMAX wavefonn and the response wavefonn
38 mmMIN.DIA.FOR
TYPE1 SOILS shall be displayed to allow the operator
-lVDT SOLID BRACKET
to adjustthe gains to ensure that they co-
LVDT~ ~
~ incide during preconditioning and
CEll PRESSURE
INLET, testing.
JHOMPSON
BALLBUSHING 6.3 Load and Specimen Response
r Measuring Equipment:
6.3.1 The axial load-measuring de-
COVER
PLATE---
vice should be an electronic load cell 10-
o. RING
SEALS cated betweenthe actuatorand the cham-
ber piston rod as shown in Figure 2. The
SAMPLE
CAP following load-cell capacities are re-
POROUS BRONZE quired:
-DISC ORPOROUS
STONE
FILTERPAPER
SpecimenDia. Max. Load Req. Accuracy
(mm) Cap. (kN) (N)
-SPECIMENMEMBRANE
71 2.2 :t4.5
-FILTERPAPER
TIE ROOS - 100 8.0 :t 10.0
POROUS BRONZE 152 22.24 :t22.24
DISC OR POROUS
STONE
BASE
BASEPLATE The aboverequirements for load ca-
, VACUUM pacity anI! accuracy are approximately
VACUUII
INLET
INLET linear when plotted versus specimen
cross-sectionarea.Requirementsfor load
cells used with other specimendiameters
SECTIONVIEW should be approximately on the samelin-
ear relationships.
Note: LVDT tips shaUresl on the Ir~x~lceU iller or on a 'NOT TOICALf ,
plall/bracket which is r~kj~ ,nached to Ih, trIax~1 tel IOU' .u -..,
If data is not available on in situ moisture 7.4 CompactionMethods and Equip- stone on the specimen,fold up the mem-
content, then refer to Section 7.3.3. The ment for Reconstituting Specimens: brane, and seal it to the top platen with
moisture content of the laboratory-com- 7.4.1 Compacting Specimens for an a-ring or some other pressure seal.
pacted specimen shall not vary by more Type 1 Materials-The general method 8.2.4 If the specimenhas been com-
than:!: 1.0 percent for Type I materials of compaction for Type I materials will pacted or stored inside a rubber mem-
or :!: 0.5 percent for Type 2 materials be that of Annex A2. brane and the porous stones and sample
from the in situ moisture content ob- 7.4.2 Compacting Specimens for are already attachedto the rubber mem-
tained. Type 2 Materials-The general method brane in place, Sections 8.2.1, 8.2.2, and
7.3.2 CompactedDensity-The den- of compaction for Type 2 materials will 8.2.3 are omitted. Instead,the .'specimen
sity of the compacted specimen shall be be that of Annex A3 or Annex A4. If it assembly" is placed on the base plate
the in-place wet density obtained in the is desiredto investigate specimendensity of the triaxial chamber.
field using T 239 or T 191. If these data gradient, the method is that of Annex 8.2.5 Connect the specimen's bot-
are not available on in situ density, then AS. tom drainage line to the vacuum source
refer to section 7.3.3. The wet density of 7.4.3 The prepared specimens shall through the medium of a bubble cham-
the laboratory-compacted specimenshall be protected from moisture change by ber. Apply a vacuumof 7 kPa. If bubbles
not vary by more than :!: 3 percent of applying the triaxial membraneand test- are present,check for leakage caused by
the in-place wet density for that layer. ing within 5 days of completion. Prior poor connections, holes in the mem-
7.3.3 If either the in situ moisture to storage, and directly after removal brane, or imperfect seals at the cap of
content or the in-place density data are from storage,weigh the specimento de- the base.The existenceof an airtight seal
not available, then use the percentageof termine if there was any moistureloss. If ensures that the membrane will remain
maximum dry density and the corre- moisture loss exceeds I percentfor Type finnly in contact with the specimen.
sponding optimum moisture content by I materials or 0.5 percent for Type 2 ma- Leakage through holes in the membrane
T 99 or T 180 as is specified by the terials, then the prepared specimen will can frequently be eliminated by coating
individual testing or transportation not be tested. However, a new specimen the surface of the membrane with liquid
will be neededto be prepared for testing. rubber latex or by using a second mem-
..
agency.The moisture contentof the labo-
ratory-compacted specimen shall not Material from the specimens not tested brane.
vary bY'"more than :!: 1.0 percent for may be reused. 8.2.6 When leakage has been elinli-
Type I materials or :!: 0.5 percent for nated,disconnectthe vacuum supply and
Type 2 materials from the targetmoisture place the chamber on the base plate and
8. Procedure- ResilientModulus the cover plate on the chamber. Insert
content. Also, the wet density of the
Test for Subgrade Soils the loading piston and obtain a fInn con-
laboratory compacted specimenshall not
vary by more than :!:3 percent of the nection with the load cell. Tighten the
8.1 The procedure described in this chamber tie rods fmnly.
target wet density.
sectionis used for undisturbedor labora- 8.2.7 Slide the assembly apparatus
Example: If the desired density is 1950
tory compacted specimens of subgrade into position under the axial loading de-
kg / m3 and the desired moisture content
soils. This can include specimensof 150- vice. Positioning of the chamber is ex-
is 8.0 percent for a Type I material, then
mm diameter or Type 2 specimens of tremely critical in elinlinating all possi-
a moisture content between 7.0 and 9.0
70 mm diameter. ble side forces in the piston rod. Couple
percent would be acceptable. For the
8.2 Assembly of Triaxial Cham- the loading device to the triaxial chamber
same desired moisture content and den-
ber-Specimens trimmed from undis- piston rod.
sity for a Type 2 material, acceptable turbed samples and laboratory-com- 8.3 Conduct the Resilient Modulus
moisture contents are between 7.5 and pacted specimensare placed in the triax- Test-The following steps are required
8.5 percent. Acceptable densities for ial chamberand loading apparatusin the to conduct the resilient modulus test on
either material are between.} 892 and a subgrade specimen which has been
following steps:
2009 kg/m3. 8.2.1 Placea moist porous stoneand installed in the triaxial chamber and
7.3.4 Sample Reconstitution-Re- moist paper [tIter on the top of the speci- placed under the loading frame.
constitute the specimen for Type I and men base of the triaxial chamber as 8.3.1 Open all drainage valves lead.
Type 2 materials in accordance with the shown in Figure 2. ing into the specimen to atmospheric
provisions given in Annex AI. The target 8.2.2 Carefully place the specimen pressure.This will simulate drained con-
moisture content and density to be used on the porous stone.Place the membrane ditions. Simulation of undrained condi-
in determining neededmaterial quantities on a membraneexpander,apply vacuum tions will require saturation of speci-
are given in Section 7.3. Annex Al pro-. to the membraneexpander,then carefully mens. Suchproceduresare not contained
vides guidelines for reconstituting the place the membraneon the specimenand in this method.
material to obtain a sufficient amount remove the vacuum and the membrane 8.3.2 If it is not already connected,
of material to prepare the appropriate expander.Seal the membraneto the ped- connect the air pressure supply line to
specimentype at the designated moisture estal (or bottom plate) with an O-ring the triaxial chamberand apply the speci-
content and density. After this step is or other pressureseal. fied pre-conditioning confining pressure
completed, specimen compaction can 8.2.3 Place a moist paper filter and of 41.4 kPa to the test specimen. A
begin. the top platen containing a moist porous contactstressof 10 percent :t 0.7 kPa of
TABLE 1 Testing Sequencefor Subgrade Soil why the sample did not attain adequate
Confining Max. Axial Cyclic Constant compaction. If this review does not pro-
No. of
Sequence Pressure,S) Stress Smax StressScyclic StressO.ISmax Load
vide an explanation, the material shall
No. -kPa p~ kPa p~- kPa Jsi kPa psi be refabricated and tested a second time.
Applications
If the sample again reaches 5 percent
0 41.4 6 27.6 4 24.8 3.6 2.8 .4 500-1 ()()()
total vertical permanent strain during
1 41.4 6 13.8 2 12.4 1.8 1.4 .2 100
2 41.4 6 27.6 4 24.8 3.6 2.8 .4 100 preconditioning, then the test shall be
3 41.4 6 41.4 6 37.3 5.4 4.1 .6 100 terminated and a notation added to the
4 41.4 6 55.2 8 49.7 7.2 5.5 .8 100 report form.
5 41.4 6 68.9 10 62.0 9.0 6.9 1.0 100 8.3.4 Testing Specimen-The test-
6 27.6 4 13.8 2 12.4 1.8 1.4 .2 100 ing is performed following the loading
7 27.6 4 27.6 4 24.8 3.6 2.8 .4 100 sequence shown in Table I. Begin by
8 27.6 4 41.4 6 37.3 5.4 4.1 .6 100 decreasing the maximum axial stress to
9 27.6 4 55.2 8 49.7 7.2 5.5 .8 100
In
13.8 kPa (SequenceNo.1, Table 1) and
27.6 4 68.9 10 62.0 9.0 6.9 1.0 100
13.8 2 1.8 1.4 set the confining pressure to 41.4 kPa.
2 13.8 12.4 .2 100
13.8 2 24.8 4 27.6 3.6 2.8 .4 100 8.3.5 Apply 100 repetitions of the
13 13.8 2 37.3 6 41.4 5.4 4.1 .6 100 corresponding cyclic axial stress using a
14 13.8 2 49.7 8 55.2 7.2 5.5 .8 100 haversine-shapedload pulse with dura-
15 13.8 2 62.0 10 68.9 9.0 6.9 1.0 100 tions as described in Section 6.2. Record
Note: Load sequences14 and 15 are not to be used for materialsdesignatedas Type 1 the average recovered deformations for
each L VDT separately for the last five
cycles on the Report Form X1.1.
the maximum applied axial stressduring test in order to recognize specimenmisplace- 8.3.6 Increase the maximum axial
each sequence number shall be main- ment and misalignment. During the precondi-
stressto 27.6 kPa (SequenceNo.2) and
tained. tioning phase, the two vertical deformation
repeat step 8.3.5 at this new stress level.
curves shall be viewed to ensurethat accept-
8.3.2.1 Loads applied to the top of 8.3.7 Continue the test for the re-
able vertical deformation ratios are being
the triaxial cell piston rod must be ad- maining load sequences in Table 1 (3
measured.The vertical deformation ratio (Rv)
justed to apply stressesshown in Table is defined as Rv = Y maxlY min' where Y max to 15), recording the vertical recovered
I after accounting for a net upward or equals the larger of the two vertical deforma- deformation. If at any time the permanent
downward resultant calculated as fol- tions and Y minequals the smaller of the two strain of the sample exceeds 5 percent,
lows: vertical deformations. Every effort shall be stop the test and report the result on the
made to achieve Rv values of 1.10 or less. appropriate worksheet. "
F = (A x P) -W Acceptable Rv values are 1.30 or less. If
8.3.8 After completion of the resili-
unacceptable vertical deformations are ob-
where: ent modulus test proced~, check the
tained (i.e., Rv is greater than 1.30), then
F = ResultantForce the test shall be discontinued and specimen total vertical permanent strain that the
A = Piston Rod Cross SectionArea placement/alignment difficulties alleviated. specimen was subjected to during the
P = Confining Pressure Once acceptable vertical deformation values resilient modulus portion of the test pro-
W = Weight of piston rod and exterior- are obtained, then the test shall be continued cedure. If the total vertical permanent
to completion. It is emphasizedthat the speci- strain did not exceed 5 percent, and if
mounted specimendeformation men alignment is critical for proper resilient
measurement system strength information is desired, continue
modulus results. This note also applies to
with the quick shear test procedure (Sec-
8.3.3 Conditioning-Begin the. test Section 9.3.3.
tion 8.3.9). If the total vertical permanent
by applying a minimum of 500 repeti- strain exceeds 5 percent,the test is com-
tions of a load equivalent to a maximum
8.3.3.1 The above stresssequence pleted. No additional testing is to be
axial stress of 27.6 kPa and correspond- conducted on the specimen, other than
constitutes sample conditioning, that is,
ing cyclic stress of 24.8 kPa using a in Section 8.3.11.
the elimination of the effects of the inter-
haversine-shapedload pulse with dura- 8.3.9 Quick Shear Test-Apply a
val between compactionand loading and
tions as described in Section 6.2. If the confining pressure of 27.6 kPa to the
the elimination of initial loading versus
sample is still decreasing in height at specimen. Apply a load so as to produce
reloading. This conditioning also aids in
the end of the conditioning period, stress an axial strain at a rate of 1 percent per
minimizing the effects of initially imper-
cycling shall be continued up to 1000 minute under a strain-controlled loading
fect contact betweenthe sample cap and
repetitions prior to testing as outlined in procedure. Continue loading until either
the test specimen.
sequenceNo. 0, Table 1. 8.3.3.2 If the total vertical perma- (1) the load values decreasewith increas-
nent strain reaches5 percentduring con- ing strain, (2) 5 percent strain is reached
NOTE 4- The laboratory/technician shall
ditioning, the conditioning process shall or (3) the capacity of the load cell is
conduct appropriate QAlQC comparative
be terminated. For recompacted samples, reached. Data from the internally
checks of the individual deformation output
from the two vertical transducers during the a review shall be conductedof the com- mounted deformation transducer in the
.:onditioning phase of each resilient modulus paction processto identify any reason(s) actuator shaft and from the load cell shall
1090 METHODS OF SAMPLING AND TESTING T307
chamber confining pressure for the test- Recordthe recoverableaxial deformation 11.3.3.7 Average-Compute the av-
ing sequence. Only one entry need be of the sample for each L VDT indepen- erageof the last five load cycles for each
made for the last five load cycles. This dently for each of the last five load cy- column.
entry should correspond exactly with the cles. Average the responsefrom the two 11.3.3.8 Standard Deviation-Com-
confining pressurelevels shown in Table L VDTs and record this value in Column pute the standard deviation of the values
I (Subgrade) or Table 2 (BaselSubbase). 12. This value will be used to calculate for each column for the last five load
11.3.3.2 Column 2-Record the the axial strain of the material. cycles using the equation:
11.3.3.5 Column 13-Compute the
nominal axial cyclic stressfor the testing
axial strain for eachof the last five load
sequence. Only one entry need be made
cycles. This value is computed by divid-
for the last five load cycles. This entry
ing column 12 by the original length of
should correspond exactly with the nomi- the specimen,La which was recorded on
nal axial cyclic stress required in Table Report Form Xl.2 (recompactedspeci-
1 (Subgrade) or Table 2 (BaselSubbase). mens) or Report Form Xl.3 (thinwall
11.3.3.3 Columns 4 through 9- tube specimens).
Record the actual applied loads and 11.3.3.6 Column 14-Compute the
stresses for each of the last five load resilient modulus for eachof the last five
cycles as shown on the worksheet. load cycles. This value is computed by
11.3.3.4 Columns 10 through 12- dividing column 8 by column 13.
At.t. SCOPE 500 g for sampleswith a maximum parti- 500 g to provide material for the determi-
cle size greater than the 4.75 mm (No. nation of moisture content at the time
AI.I The following procedure pro- 4) sieve. of compaction.
vides guidelines for reconstituting the Al.l.2.1 Detennine the appropriate Wad = (W.+Was) (I+w) /100)
material to be tested so as to produce a total volume (V) of the compactedspeci-
sufficient amount of material neededto men to be prepared. The total volume where:
prepare the appropriate sample type must be based on a height of the com-
pacted specimenslightly greaterthan that Wad = Mass of sample at water content
(Type I or Type 2 sample) at the desig-
nated moisture content and density. required for resilient testing to allow for WI, g
trimming of the specimenends if neces- Was = Mass of moisture content speci-
AI.I.I Sample Conditioning-If the
sary. Compacting to a height/diameter men (usually 500 g), g
sample is damp when received from the
ratio of 2.1 to 2.2 will provide adequate WI = Water content of prepared mate-
field, dry it until it becomes friable.
Drying may be in air or by useof a drying material for this purpose. rial, percent
apparatusas long as that the temperature Al.l.2.2 Detennine the mass of Al.l.2.4 Determine the mass of
does not exceed 60°C. Then thoroughly oven-dry soil solids (W.) required to ob- water (Waw ) required to change the water
break up the aggregations in sucha man- tain the desired dry density ('Y~ and content from the existing water content,
ner as to avoid reducing the natural size moisture content (w) as follows: WI, to the desired compaction water con-
of individual particles. Moderate pres- W. = 453.59 'YdV tent, w. (See Section 7.3.3)
sure using a rubber-covered implement
to push the particles through a 4.75 rnm where: Waw = (W.+Was) [(W-WI) / 100]
(No.4) sieve has been found to be ade- W s = massof oven-dry solids,g where:
quate to break down clay lumps. 'Yd= desireddry density, lb Ift3
AI.I.2 Sample Preparation-De- V = total volume of compactedspeci- Waw = Mass of water neededto obtain
termine the moisture content (WI) of the water content, w, g
men, ft3
sample as per AASHTO T-265. The w = Desired water content of com-
mass of the moisture content specimen Al.l.2.3 Determine the mass of the pacted material, percent
shall be at least 200 g for samples with dried sample, Wad, with the moisture
content WI, required to obtain W s plus Al.l.2.5 Placea sampleof massWad
a maximum particle size smaller than
the 4.75 rom (No.4) sieve and at least an additional amount Was of at least into a mixing pan.
Al.l.2.6 Add the mass of water Al.l.2.7 Placethe mixture in a plas- and record this value on Report FonIl
(waw)neededto changethe water content tic bag. Seal the bag,place it in a second XI.2.
from WI to W, to the sample in small bag and seal it. Cure the sample for 16 Al.l.2.8 The material is now ready
amountsand mix thoroughlyafter each to 48 hours, detennine the mass of the for compaction.
addition. wet soil and containerto the nearestgram
A2.1. SCOPE A2.3 Procedure Detennine the total height of the top and
bottom platens and stones to the nearest
A2.1.1 Soils will be recompacted A2.3.1 For removable platens, 0.25mm.
tighten the bottom piaten into place on A2.3.3 Remove the top platen and
using a split mold and vibratory compac-
tion. Selectmold sizesto fabricate speci- the triaxial cell base. It is essential than bronze disc if used. Measure the thick-
mens of a minimum diameter equal to an airtight seal is obtained and that the ness of the rubber membrane with a
5 times the maximum particles size. If bottom plateninterfaceconstitutesa rigid micrometer.
the maximum particle size exceeds 25 body since calculations of strain assume A2.3.4 Place the rubber membrane
percent of the largest mold diameter zero movement of the bottom platen over the bottom platen and lower bronze
available, theseparticles shall be scalped. under load. disc. Securethe membraneto the bottom
Length of all specimens will be at least A2.3.2 Place the two porous stones platen using an a-ring or other means
2 times the diameter. and the top platen on the bottom platen. to obtain an airtight seal.
A2.1.2 Specimens shall be com-
pacted in 6 lifts in a split mold mo'Unted
on the base of the triaxial cell as shown
in Figure A2.1. Compaction forces are
generated by a vibratory impact hammer
without kneading action powered by air
or electricity and of sufficient size to
provide the required laboratory densities
while minimizing damageto the sample
membrane.
A2.2 Apparatus
A2.2.1 A split mold, with an inside
diameter of 152 rom having a minimum
height of 381 rom (or a sufficient height
to allow guidanceof the compactionhead
for the final lift).
A2.2.2 Vibratory Compaction De-
vice- Vibratory compaction shall be
provided using electric rotary or demoli-
tion hammers with a rated input of 750
to 1250 watts and capable of 1800 to
3000 blows per minute. NcM
1:~ I.8d be...! 0.1-(0. ! 0.02')
~ '- ~ ~.
A2.2.3 The compactor head shall be
FIGURE A2.1 Typical Apparatus for Vibratory Compaction of Type 1 Untreated
at least 13-rom thick and have a diameter
of not less than 146 mm. Materials
1094 METHODS OF SAMPLING AND TESTING T 307
A2.3.5 Place the split mold around the mass of wet soil, WL required for scarifying the top surface of the previous
the bottom platen and draw the mem- each layer. layer to a depthof 6.4 mm. The measured
brane up through the mold. Tighten the distance from the surface of the com-
split mold firmly in place. Exercise care WL = WI N pacted layer to the rim of the mold is
to avoid pinching the membrane. successivelyreduced by the layer thick-
A2.3.6 Stretch the membrane tightly where: ness selected in step B3.10. The final
over the rim of the mold. Apply a vac- W t = to total massof test specimen surface shall be a smooth horizontal
uum to the mold sufficient to draw the plane. As a recommended final step
membrane in contact. If wrinkles are produceappropriatedensity where porous bronze discs are used, the
Nt = numberof layers to be compacted
presentin the membrane,releasethe vac- top plate shall be placed on the sample
uum, adjust the membrane and reapply A2.3.11 Place the total required and seated with the vibrator head. If
the vacuum. The use of a porous plastic mass of soil for all lifts, Wad, into a necessary,due to degradationof the first
forming jacket line helps to ensure that mixing pan. Add the required amountof membrane, a second membrane can be
the membrane fits smoothly inside the water, Waw,and mix thoroughly. applied to the sample at the conclusion
mold. The vacuum is maintained A2.3.12 Determine the mass of the of the compaction process.
throughout the compaction procedure. wet soil and the mixing pan. A2.3.16 When the compaction pro-
A2.3.7 Measure,to the nearest0.25 A.2.3.13 Place the amount of wet cess is completed, determine the mass
mm, the inside diameter of the mem- soil, W L, into the mold. Avoid spillage. of the mixing pan and the excess soil.
brane-lined mold and the distance be- Using a spatula, draw soil away from This mass subtracted from the mass de-
tween the top of the lower porous stone the inside edge of the mold to form a termined in step A2.3.12 is the mass of
and the top of the mold. small mound at the center. the wet soil used (mass of specimen).
A2.3.8 Determine the volume, V, of A2.3.14 Insert the vibrator and vi- Verify the compaction water, W c, of the
the specimen to be prepared using the brate the soil until the distance from the excess soil using care in covering the
diameter determined in step B3.7 and a surface of the compacted layer to the pan of wetted soil during compaction to
value of height between 305 to 318 mm. rim of the mold is equal to the distance avoid drying and loss of moisture. The
A2.3.9 Detem1inethe mass of mate- moisture content of this sample shall be
measuredin stepA2.3.7 minus the thick-
rial, at).he prepared water content, to be conducted using AASHTO T 265.
nessof the layer selectedin stepA2.3.1O.
compacted into the volume, V, to obtain A2.3.17 Proceed with Section 9 of
This may requireremoval and reinsertion
this method.
the desired density. of the vibrator severaltimes until experi-
A2.3.10 For 152-mm diameter spec- ence is gained in gaging the vibration NOTE I-As an alternative for soils lack-
imens (specimen height of 305 mm) six time which is required. ing in cohesion, a mold with the membrane
layers of 50 mm per layer are required A2.3.15 Repeat steps A2.3.13 and installed and held by vacuum, as in Annex
for the compaction process. Determine A2.3.14 for each new layer after first A2, may be used.
A3.1. SCOPE that is fIXed by the dimensions of the installed and held by vacuum, as in
mold assembly.The minimum mold di- Annex A2, may be used. Several steps
A3.1.1 This method covers the com- ametershallbe 71 rnm. Selectmold sizes are required for static compaction as fol-
paction of Type 2 soils for use in resilient to fabricate specimens of a minimum lows in Section A3.3 of this Annex and
modulus testing. diameter equal to 5 times the maximum as illustrated in Figures A3.2 to A3.6.
particles size. If the maximum particle A3.2 Apparatus-The apparatus is
A3.1.2 The general method of com-
size exceeds 25 percent of the largest as shown in Figure A3.1.
paction of Type 2 soils will be that of
static loading (a modified version of the mold diameter available, these particles
double plunger method). If testable thin- shall be scalped.Length of all specimens
walled tubes are available, specimens will be at least 2 times the diameter. A A3.3 Procedure
shall not be recompacted. typical mold assemblyis shownin Figure
A3.1.3 The process is one of com- A3.1. As an alternative for soils lacking A3.3.1 Five layers of equal mass
pacting a known massof soil to a volume in cohesion,a mold with the membrane shall be used to compact the specimens
T 307 METHODS OF SAMPLING AND TESTING 1095
Step3.7-Lift2:
.Measure correct wet mass of soil to
use for a layer.
.Place in mold, spade.
.Insert 71.6 mm (2.820") plug.
.Plunge until plugs are flush with top
and bottom of mold.
.Flip mold over and remove 100.1 mm
(3.940") plug, keeping the 71.6 mm
(2.820") plug in place.
.Scarify the exposed surface of Lift 1
.Proceed with next step.
tL
71.6 mm
(2.820")
height
Lift 2
Lift 1
100.1 mm
(3.940")
height
,G
1098 METHODS OF SAMPLING AND TESTING T 307
,c
71.6 mm
(2.820")
height
Lift 2
Lift 1
Lift 3
71.6mm
(2.820")
height
l
T307 METHODS OF SAMPLING AND TESTING 1099
L
:;"" 43.2 mm :;:,
':., (1.700; .' ,
~!:~i.;.heig~~..:..:,:(;:
Lift 4
Lift 2
Lift 1
Lift 3
71.6mm
(2.820")
height
P-,
100 METHODS OF SAMPLING AND TESTING T307
Step3.13-lift5:
.Measure correct wet weight of soil to use
for a layer.
.Place in mold, spade.
.Insert 43.2 mm (1.700") plug
.Plunge until plugs are flush with top and
bottom of mold.
.Extrude compacted sample from mold
using extruding apparatus or extrusion
mold.
.Place in rubber membrane.
.Test for Mr.
...c
43.2 mm
(1.700")
height
Lift 4
Lift 2
Lifl1
Lift 3
liftS
43.2 mm
(1.700")
height
P--,
T307 METHODS OF SAMPLING AND TESTING 1101
a material which will not absorb soil A3.3.16 Place a platen similar to the the membrane to each platen using 0-
moisture. one used in step A3.3.13 on top of the rings or other means to provide an air-
A3.3.15 Determine the mass of the specimen. tight seal.
compacted specimento the nearestgram. A3.3.17 Using a vacuummembrane A3.3.18 Proceed with Section 8 of
Measure the height and diameter to the expander,place the membrane over the this method.
nearest 0.25 ffiffi. Record these values specimen. Carefully pull the ends of the
on Report Form XI.I. membrane over the end platens. Secure
2.
1. SAMPLE
MATERIAL NUMBER
TYPE -
4.
3. RESIUENT
TEST DATE MODULUS TESTING
ReportFonn XI.I
ResilientModulus of SubgradeSoils andUntreatedBase/Subbase
Materials
(RECOMPACfED SAMPLES)
SAMPLING
DAm: 19_-
2. SAMPLE NUMBER
5. SPECIMENINFO.:
SPEC. DIAM., mm
TOP ---"-
MIDDLE ___O-
BOTTOM ___O-
AVERAGE ___O-
MEMBRANE nnCKNESS(l), mm
MEMBRANE nnCKNESS(2), mm
NET DIAM, mm ___O-
HEIGHT OF SPECIMEN,CAP AND BASE, mm ___O-
HEIGHT OF CAP AND BASE, mm ___O-
INITIAL LENGTH Lo, mm ___O-
INITIAL AREA, Ao, mm2 O
INITIAL VOL~E, AoLo' mm3 "
6. SOIL8PECIMEN WEIGHT:
INlTIAL WEIGHT OF CONTAINER AND WET SOIL, grams
FINAL WEIGHT OF CONTAINER AND WET SOIL, grams °_-
WEIGHT OF WET SOIL USED, grams ~
7. SOIL PROPERTIES:
IN srru MOISTURE CONTENT (NUCLEAR), PERCENT -
IN srru WET DENSITY (NUCLEAR), kgimJ ---'---, ,.,..
or
OPTIMUM MOISTURE CONTENT, PERCENT
MAX. DRY DENSITY, kgim3
95 PERCENTMAX. DRY DENSITY, kgim3
--- ~~.~
-,"-0':"";
8. SPECIMENPROPERTIES:
COMPACTION MOISTURE CONTENT, PERCENT __°-
MOISTURE CONTENTAFTER RESILIENT MODULUS TES11NG,PERCENT
COMPACTION DRY DENSrrY, "Yd'kg/mJ O-
TESTED BY DATE
ReportForm XI.2
T 307 METHODS OF SAMPLING AND TESnNG 1103
I. SAMPUNGDATE: _-19-
2. SAMPLE NUMBER
5. TEST INFORMATION
PRECONDmONING -GREATER THAN 5 PERCENT PERM. STRAIN? (Y = YES OR N = NO)
TESTING -GREATER THAN 5 PERCENT PERM. STRAIN? (Y = YES OR N = NO)
TESTING -NUMBER OF LOAD SEQUENCES COMPLETED (0 -15)
6. SPECIMENINFO.:
SPEC.DIAM., mm
TOP
MIDDLE
BOTTOM ---"-
AVERAGE ---"-
MEMBRANE TIllCKNESS(I), mm -"--
MEMBRANE TIllCKNESS(2), mm -"--
NET DIAM. mm ---"-
INmAL LENGTH La, mm ---"-
INrrIAL AREA, Ao, mm2 "
INITIAL VOLUME, AoLo,mm3 "
INmAL WEIGHT, grams "-
7. SOIL PROPERTIES:
IN SITU MOISTURE CONTENT, PERCENT --'-
MOISTURE CONTENT AFTER RESILIENT MODULUS TESTING, PERCENT --'-
WET DENSrrY, 'Yw'kg/m3
DRY DENSrrY, 'Yd'kg/m3 . '-
9. TEST DATE
TESTEDBY. DATE
ReportForm XI.3
ANNEX A4 -Kneading Compaction of Type 2 Soils
A4.1 SCOPE
-L
A4.1.1 This method covers kneading T =C:::::Ip:
~ I.D.
38 mrn ~ C :.:
compaction of Type 2 soils for use in
resilient modulus testing.
ExtensionCollar
A4.1.2 Specimens shall be com-
pacted in five lifts (layers) in a split mold.
Either a pneumatic manual compactor or
a hydraulic mechanical compactor pro-
vides the compactive effort. The number
of tamps per lift and the compaction
H
pressure are constant for all lifts. The
compaction pressure is adjusted to
achieve the required laboratory density.
Split Mold
I
NOTE 5-Caution. The piston should not
Air be moved all the way to the end of the
,=
Supply T compactor, as this will cause an unregulated
L force to be applied.
1
A4.4.6 Lightly scarify the top SUf-
face of the compacted lift to a depth of
NOTES 3 rom priOf to placing soil in the mold
fOf the next lift.
I. L = SpecimenHt. + Collar Ht. -Layer HL + 12mm. A4.4.7 Repeat A4.4.5 and A4.4.6
2. Minimum reservoirvolume= 200 X compactorvolume. until 5 lifts have been compacted. Con-
3. Minimum gaugeaccuracyis 0.5 kPa. tinue with Section A4.6.1.
4. Compactorair cylinder is rolling diaphragmtype.
1
1106 METHODS OF SAMPLING AND TESllNG T 307
A4.5.6 RepeatA4.5.3 throughA4.5.5 A4.6.2 Detennine and record the A4.6.5 If the average density differs
until 5 lifts have been compacted. massof the entire specimento the nearest from the target density by more than the
gram. Use a tabular form, as in Figure tolerance allowed in Section 7.3.2 or
A4.3, to record the data. 7.3.3, thenthe compaction pressure shall
A4.6 SpecimenTrimming and A4.6.3 Detennine and record the be adjusted to increase or decreasethe
Calculations moisture content of the remaining soil averagedensitytoward the target density.
according to AASlffO T 265. Repeat A4.4 or A4.5.
A4.6.1 Remove the collar and care- A4.6.4 Calculate and record the av-
fully screed off the specimento the top erage bulk (wet) density of the entire
NOTE 6-If a sufficient quantity of mate-
of the mold. Small depressions in the specimen,"Ys.If the averagedensity dif- rial is available, it is preferable to use new
screeded surface, caused by removal of fers from the target density by less than material for each subsequentspecimen. If the
larger particles, shall be filled with fines. the tolerance allowed in Section7.3.2 or old material is reusedthis will have an effect
Remove the split mold from the base 7.3.3, then proceed with Section 7.4.3 on the structure of subsequently compacted
and the mold halves from the specimen. of this method. specimens.
PROJECT
SpecimenNo.
Wt. of scalpedsoil (gins)
No. Tamps per Layer
Air o(Tamper Foot Pressure(Pa)
Wt. specimen& mold (gms)
Wt. mold assembly(gins)
Wt. moist soil (gms)
Wt. dry soil (gms)
Moistllre
I Dry Content
Density (%)
(kg/m3) -
PERCENTDIFFERENCES
Target& SpecimenDry Density(%)
Target& SpecimenMoisture (%)
REMARKS
FIGURE A4.3
I
T307 METHODS OF SAMPLING AND TESTING 1107
SCOPE ~ I; ~h
38mm'-1 J i. I
AS.I.I This method provides proce-
dures for measuring and minimizing or T I-IoDo-1:L ExtensionCollar
eliminating density gradients in a speci-
men of Type 2 soil for use in resilient H/36
modulus testing. [~~~~~:=~]
1
AS.I.2 Specimens shall be com- Recess for
pacted in five lifts (layers) in a density 1-1- Density Ring
(typ.)
gradient mold. Kneading compaction H
(Annex A4) shall be used. The number
of tamps per lift shall be adjusted for T
each lift to avoid imparting a density
gradient to the specimen. ~llil~ ~-L
T- H/36
Split Mold
Significanceand Use
A5.4.3 Remove the collar and care- A5.4.6 Using a hacksaw or other A5.4.9 Calculate and record the av-
fully screed off the specimen to the top abrasive device, carefully cut the speci- erage bulk (wet) density of the entire
of the mold. Small depressions in the rnen into 5 pieces. Each cut should be specimen, 'Ys, and densities of each of
screeded surface, caused by removal of rnade midway betweenthe rings. Screed the 5 pieces, 'YI to 'Ys.
larger particles, shall be filled with fines. off each piece to form square ends at
Remove the split mold from the base the top and bottorn of each ring. Srnall
and the mold halves from the specimen. depressions in the screeded surface,
Leave the five rings on the specimen. caused by rernoval of larger particles, A5.4.10 If the maximum difference
A5.4.4 Determine and record the net shall be filled with fines. between the density of each individual
massof the entire specimento the nearest A5.4.7 Determine and record the net piece and the average density is 1.0 per-
gram. To do this subtract the mass of rnassof eachnumberedpiece to the near- cent or less, report the density gradient
the rings from the mass of the specimen estgram. Use a tabular form, as in Figure as being ulllform. If the maximum differ-
with rings attached. AS.2, to record the data. encebetweenthe density of each individ-
A5.4.5 Determine and record the A5.4.8 Determine and record the ual piece and the averagedensity is more
moisture content of the remaining soil rnoisture content of each nurnbered than 1.0 percent, report the density gra-
according to AASHTO T 265. piece. dient as beingnon-uniform.
I PROJECI' I I
I SampleNo. I I SoilDescription I. I
Target Moisture (IJ.) Target Density (kg/m3) * Air or Tamper Foot Pressure (Pa)
Was Simple Scalped? Wt. scalped soil (gms) Mold Dimensions -diarn. x ht. (mm)
Ring Volume (cm3) I ~
Wei hts
Layer **Order of Ring No. *No. of Ring Soil Water Moisture Layer PercentDifference
Position Compaction Temps (dry) (%) Dry Density BetweenAverageDensity
in Mold per Layer (kg/m3) & Layer density
* Requiredfor kneadingcompaction(AnnexA4).
** For static compaction,middle layer is usuallyfirst.
For kneadingcompaction,bottom layer is first.
REMARKS
FIGUREAS.2
~~
T 307 METHODS OF SAMPLING AND TESTING 1109
AS.S Procedure for Compacting each lift in the first trial specimen in order density is non-unifonn hold the compac-
to establish that a density gradient doesexist. tion pressure constant and adjust the
Test Specimensto Achieve a
number of tamps per lift until a unifonn
Uniform Density
density gradient is achieved.