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APPENDIX E TEST PROCEDURE FOR RESILIENT MODULUS OF UNSTABILIZED AGGREGATE BASE AND SUBGRADE MATERIALS E-1

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RECOMMENDED STANDARD METHOD FOR ROUTINE RESILIENT MODULUS TESTING OF UNBOUND GRANULAR BASE/SUBBASE MATERIALS AND SUBGRADE SOILS 1. Scope ~ . ~ This test method describes the laboratory preparation and testing procedures for the routine determination of the resilient modulus (Mr) of unbound granular base/sub-base materials and subgrade soils for pavement design. The stress conditions used in He test represent the range of stress states likely to be developed beneath flexible pavements subjected to moving wheel loads. This test procedure has been adapted from the standard test methods given by AASHTO DESIGNATION: T29~92I, TP46 and T292-9I. I.2 The mesons described are applicable to: (~) undisturbed samples of natural and compacted subgrade soils, and (2) disturbed samples of unbound base, subbase and subgrade soils prepared for testing by compaction in the laboratory. I.3 In this test procedure, stress states used for resilient modulus testing are based upon whether the specimen is located in the base/ subbase or He subgrade. Specimen size for testing generally depends upon the type of material and is based upon its gradation and the plastic limit as described in a later section. I.4 The value of resilient modulus determined from this procedure is a measure of He elastic modulus of unbound base and subbase materials and subgrade soils recognizing certain nonlinear characteristics. I.5 Resilient modulus values can be used with structural response analysis models to calculate He pavement structural response to wheel loads, and with pavement design procedures to design pavement structures. I.6 The values stated in ST unites are to be regarded as He standard. I.7 This standard may involve hazardous materials, operations, awl equipment. This standard does not purport to address aR of the safety problems associated with its use. It is the responsibility of whoever uses this standard to consult arm establish appropriate safety and health practices arm determine the applicability of regulatory limitations prior to use. Note ~ -- Test specimens and equipment described in this method may be used to obtain other useful and related information such as the Poisson's ratio and rutting characteristics of subgrade soils and base/subbase materials. Procedures for obtaining these are not covered in this standard. 2. Referenced Documents 2. ~ AASHTO Standards T88 T89 T90 T99 T233 T265 T238 E_2 Particle Size Analysis of Soils Determining the Liquid Limit of Soils Determining the Plastic Limit and the Plasticity Index of Soils The Moisture-Density Relations of Soils Using a 5.5 Ib. Rammer and 12-Inch Drop TI00 Specific Gravity of Soils TI80 Moisture-Density Relations of Soils Using a 10-lb. (454 kg) Rammer and an IS in. (457 mm) Drop Density of Soil-in-Place by Block, Chunk or Core Sampling T234 Strength parameters of soils by Triaxial Compression Laboratory Determination of Moisture Content of Soils Density of Soil and Soil-Aggregate in Place by Nuclear Methods (Shallow Depth

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T239 Moisture Content of Soil and Soil- Aggregate in Place by Nuclear Me~ods (Shallow Depth 3. Terminology 3.! Unbound Granular Base and Subbase Materials: These include soil-aggregate mixtures and naturally occurring materiels. No binding or stabilizing agent is used to prepare unbound granular base or subbase layers. These materials may be classified as either Type ~ or Type 2 as subsequently defined in 3.3 and 3.4. 3.2 Subgrade: Subgrade soils may be naturally occurring or prepared and compacted before Me placement of subbase and/or base layers. These materials may be classified as either Type ~ or Type 2 as subsequently defined in 3.3 and 3.4. 3.3 Material Type I: For the purposes of resilient modulus testing, Material_Type ~ includes all unbound granular base and subbase material and all untreated subgrade soils which meet Me criteria of less than 70% passing Me 2.00 mm (No. 10) sieve and less Man 20% passing the 75 Am (No. 200) sieve, and which have a plasticity index ~ 10. Type la material shall have 100% passing 37.5 mm (1.5 in.) sieve and Type lb the 25.4 mm (1.0 in.) sieve. Materials~ciassified~ype la shall be molded in a 152 man (6 inch) diameter mold. Materials classified as lb can be molded in either a 102 mm (4 in.) or 152 mm (6 in.) diameter mold. Note 2 - If logo or ~ of a Type la sample is retained on the 37.5 mm (1.5 in.) sieve, Me material greater than the 37.5 mm (~.5 in.) sieve shall be scalped and replaced by 25.4 to 37.5 mm (1.0- 1.5 in.) material prior to testing. 3.4 Material Type 2: Material Type 2 includes all unbound granular base/subbase and untreated subgrade soils not meeting the criteria for material Type ~ given above in 3.3. Generally, thin-walled tube samples of untreated subgrade soils fall in Me Type 2 category. Remolded Type 2 specimens can be compacted in either a 71 xnm (2.8 in.) or a 102 mm (4 in.) diameter mold. Note 3 -- Type 2, 71 mm (2.8 in.) Specimens: If 10% or ~ of a Type 2 sample is retained on the 12.5 mm (0.5 in.) sieve, the material greater than 12.5 mm (0.5 in.) shall be scalped off and replaced by 9.5 mm to 12.5 mm (0.375 in. to 0.5 in.) material prior to testing. 3.5 Resilient Modulus of Type I and Type lI Materials: The resilient modulus of Type I and Type I! material is determined by repeated load compression tests on test specimens of the unbound material. Resilient modulus (Mr) is the ratio of Me peak axial repeated deviator stress to the peak recoverable axial strain of the specimen. 3.6 Loading Wave Form - Test specimens are loaded using a haversine load pulse as shown in Figure Eel. 3.7 Maximum Applied Axial Load (Pmax) ~ the load applied to the sample consisting of the contact load and cyclic load (confining pressure is not included): Pm" Poon~, + Pcyclic 3.S Contact Load (PCon~ac~) ~ vertical load placed on Me specimen to maintain a positive contact between the loading ram and the specimen top cap. The contact load includes the weight of the top cap and the static load applied by the ram of the testing system. 3.9 Cyclic Axial Load - repetitive load applied to a test specimen: P`~rclic = Pmax Pconta~ 3.10 Maximum Applied Axial Stress (Sm=) - the axial stress applied to Me sample consisting of the contact stress and the cyclic stress (~e confining stress is not included): Sma,c = Pmax/A E-3

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Do O gO 180 270 360 i ' I ' i ' I ' I ~ 1.0- 0.8- - co - 0.6- C) o C' 0.2- 0.0 ,` 0.1 seG / Load Duration .,___________. . Cyclic (Resilient) Load Pulse (Pi ) , ~ ~ \ Maximu nil App' ed \ Load (Pmac ) \ O.9S~ Rest Pedod Haversine Load Pulp (1-CDS 8) . \ Contact Lt lad (POOl~ ) 1 1 ~ r1 1 ~ O .02 .04 .OB .08 JO Time, Seconds (t) Figure Eat. Definition of resilient modulus terms E-4 - 100 - 90 -80 -70 :- - 60 ~ m _ 50 O S. -40 -30 ~ - -20 - 10 o

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where: A = cross sectional area of the sample. 3 . ~ ~ C ye! ic Axial Stress - cyc! ic (res i! ient) applied axial stress: S~,C,ic = PCyclidA 3. 12 Contact Stress (SoOn~ - axial stress applied to a test specimen to maintain a positive contact between the specimen cap and the specimen: Scone, = PCon~,/A The contact stress shall be maintained so as to apply a constant an~sotropic confining stress ratio (SO>n~ + S31/S3 I.2. where: S3 iS the confining pressure. 3.13 S3 IS the applied coding pressure in the biaxial chamber (i.e., the minor principal stress, (731 3.14 er is the resilient (recovered) axial deformation due to S~c~ic. 3.15 Er is the resilient (recovered) axial strain due to S~c~ic: Cr = er/L where: ~ = distance between measurement points for resilient axial deformation, en 3.16 Resilient Modulus (Mr) is defined as SFyctic/Er 3.17 Load duration is the time interval Me specimen is subjected to a cyclic stress pulse (usually 0. ~ sec.~. 3.~S Cycle duration is Me time interval between the successive applications of a cyclic stress (usually I.0 sec.~. 4. Summary of Method 4. ~ A repeated axial stress of fixed magnitude, load~uration (0.l sec.), and cycle duration (l sec.) is applied to a cylindrical test specimen. Me test is performed on cohesioniess materials in a biaxial cell and the specimen is subjected to a repeated (cyclic) stress and a constant confining stress provided by means of cell air pressure. For cohesive subgrade soils a similar repeated cyclic stress is applied to an unconfirmed cylindrical specimen. The total resilient (recoverable) axial deformation response of the specunen is measured and used to calculate the resilient modulus. 5. Significance and Use 5. ~ The resilient modulus test results provides a basic constitutive relationship between stiffness and stress state of pavement materials for use in pavement design procedures and the structural analysis of layered pavement systems. The resilient modulus test simulates the conditions in a pavement due to application of moving wheel loadings. As a result, the test provides an excellent means for comparing the behavior of pavement construction materials under a variety of conditions (i.e., moisture, density, gradation, etc.) and stress states. 6. Resilient Modulus Test Apparatus 6. ~ Triaxial Pressure Chamber: CohesionIess Materiads - The pressure chamber is used to contain Me test specimen and Me confining fluid during Me test. A typical biaxial chamber suitable for use in resilient testing of soils is shown in Figure E-2a. The axial deformation is measured internally directly on the specimen using either an optical extensometer, noncontact sensors or clamps (Figure E-2a). 6. I. ~ Air shall be used in the biaxial chamber as the confining fluid for all testing. E-5

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LOADING CON \\ ~ COYER PLATE - CHAMBER CLAMP MOUNTED LYDT TEST SPECIMEN ~ SPECIMEN METER - E - THOMPSON UNEAR ~onoN BEARINGS _ RUBBER GASKET LOAD An L CONNECTOR _ LOAD (:aL E ROD -LVOT J" BOSOM _ CHAIJiDER _ ALUMNUS ROD _ BRONZE POROUS STONE EXTERNAL=NNE=OR ~ ~ ^\\\~= ~ IN~NAGE ONE '' A' ~ RUBBER GASKET ~ ~ ~ BOhOM C" ~ RING SEAL (a) Triaxial Cell L" LVDT AND LOAD CEl1 CONNECT - S 2~ ~ LOAD RAM STEEL BALL / ATOP PLATEN 3~4/ (SOLID) A, , ~ in , ,, aid ~-LVDT CAL l T ~ SPECIMEN ~ , , ~ BOTTOM / PLATEN (SOLID) \ \ \ \ \ ~ BASE OF LOAD FRAME (b) Unconfined compression test Figure E-2. Triaxial and unconfined test apparatus E-6

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6.~.2 The chamber shall be made of Lexan, Acrylic or other suitable "see-through" material. If an optical extensometer is used the line of sight must pass Trough a flat face of the chamber. Hence, a standard cylindrical chamber cannot be used with an optical extensometer. 6.2 Unconfined Test: Cohesive Subgrade Soils - An undrained, unconfined compression test shall be performed on cohesive subgrade soils (Figure E-2b). Solid, rigid steel or aluminum platens are placed on the top and bottom of the specimen which may be enclosed in a rubber membrane. The specimen is subjected to only atmospheric air pressure, and hence a biaxial cell is not required in the test. The axial deformation of firm or stiff subgrade specimens, except as noted, is measured on the specimen using one of the me~ods given in Section 6. For soft and very soft subgrade specimens (i.e., Su ~ 361d'a or 750 psf), clamps should not be used since they may damage He specimen. However, a pair of EVDTs extending between He top and bottom platens can be used to measure axial deformation of these weak soils. 6.3 Loading Device - The loading device shall be a top loading, closed loop electrohydraulic testing machine with a function generator which is capable of applying repeated cycles of a haversine-shaped load pulse. Each pulse shall have a 0. ~ sec. duration followed by a rest periods of 0.9 sec. duration. For nonplastic granular materials, it is permissible, if desired, to reduce He rest period to 0.4 sec. to shorten testing time: He load pulse time may be increased to 0. 15 sec. if required. 6.3.] The haversine shaped load pulse shall conform to Section 3.6 except as noted above. All conditioning and testing shall be conducted using a haversine-shaped load pulse. The electro-hydraulic system generated haversine waveform and He response waveform shall be displayed to allow the operator to adjust He gains to ensure they coincide during conditioning and testing. 6.4 Load and Specimen Response Measuring Equipment: 6.4. ~ The asocial load measuring device should be an electronic load cell located inside the biaxial cell as shown in Figure E-2a. The following load cell capacities are required: Sample Dia. Max. Load Cap. Req. Accuracy mm. (in.) kN (lbs.) ~ fibs.) 71~2.8) 2.2~500) i4.5(il) 102 (4.0) 8.9 (2000) il7-8 (i 4) 152 (6.0) 22.24 (5000) i 22.24 (i 5) Note 4 -- Since applied stress levels are low, a non-fatigue rated load cell can be used to obtain a greater voltage output and higher accuracy than for a fatigue rated cell. Do not load a non-fatigue rated load cell to more than 50% of its rated capacity. During periods of resilient modulus testing, the load cell shall be monitored and checked once every two weeks or after every 50 resilient modulus tests with a calibrated proving ring to assure that the load cell is operating properly. An alternative to using a proving ring is to insert an additional calibrated load cell and independently measure the load applied by Me original load cell. Additionally, the load cell shall be checked at any time there is a suspicion of a load cell problem. Resilient modulus testing shall not be conducted if the testing system is found to be out of calibration. 6.4.2 The test chamber pressures shall be monitored wig conventional pressure gages, manometers or pressure transducers accurate to 0.7 kPa (O. ~ psi). E-7

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6.4.3 Axial Deformation - Axial deformation is to be measured on the specimen using one of the following devices: (~) optical extensometer, (2) noncontact sensors or (3) clamps attached to the specimen. Table E-! summarizes the specifications for noncontact and clamp measurement devices. Deformation shall be measured over approximately the middle 1/2 of the specimen For methods (2) and (3) above, deformation shall be measured independency on each side of the specimen using gages having the maximum practical sensitivity. 6.4.3.! Optical Extensometer - The optical extensometer should have at least the following minimum requirements: (~) resolution - 0.0002 in.; (2) frequency response - 200 hz bandwidth; (3) linearity - O. ~ %; (4) displacement range - 0.5 in.; (5) gage length range: 2.5 in. to 5.0 in.; (6) analog or digital output signal. If displacement is measured on a single side of the specimen, two external or internally mound EVDTs or dial indicators should be used to determine specimen eccentricity under loading. 6.4.3.2 Noncontact Proximity Sensors - Proximity gages shall have the minimum voltage output given in Table Eel. 6.4.3.3 Clamps Mounted EVDTs - EVDTs shall have the minimum voltage output indicated in Table E-! A pair of spring loaded clamps are placed on the specimen et I/4 point. (Figure Ebb. Each clamp shall be rigid with the clamp weight not exceeding the following values: 6 in. clamp - 2.4 N (0.55 Ibs.~; 4 in. clamp - I.8 N (0.40 Ibs.~; 2.8 in. clamp - I.0 N (0.22 Ibs.~. Minimize clamp weight by Uniting small holes in the clamp. Clamp spring force should be as follows: 6 in. clamp 44.5 N (10.0 Ibs.~; 4 in. clamp - 33.4 N (7.5 Ibs.~; 2.8 in. clamp- 18.2 N (4.1 lbs.~. Use two pairs of 12 mm (0.5 in.) diameter rods, cut to the correct length, to position the clamps in a horizontal plane at the correct location on the specimen. 6.4.3.4 Spring loaded EVDTs shall be used to maintain a positive contact between the EVDT's and the surface on which the tips of the transducers rest. If the specimen is soft enough to be damaged by clamps or slippage of clamps is suspected, use one of the other alternative axial displacement measurement techniques. Slippage of clamps may be a problem for soft and very soft subgrade soils which undergo large deformations. Specimen damage due to clamps and clamp slippage should not be a problem for reasonable quality base and subbase specimens. The two EVDT's, or proximity gages, shall be wired so that each transducer is read, and the results reviewed, independency. The measured displacements shad be averaged for calculating the resilient modulus. Note 5 -- Misalignment, or dirt on the shaft of the transducer can cause the shafts of the EVDTs to stick. The laboratory technician shall depress and release each EVDT back and forth a number of times prior to each test to assure that they move freely and are not sticking. A cleaner/lubncant specified by the manufacturer shall be applied to the transducer shafts on a regular basis. E-8

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Table Eat. Specifications for axial EVDT and noncontact proximity deformation measurement instrumentation I - 1 hlATERIAL~oECIMEll SIZE hilts APPROX. ~INUW~ Row RESILIENT Am. (IN.) SPEC - N OUTPUT (+I-) D~P. ~.) (MV) TYPICAL LVDT M~. S~ O 3Y, MVNI0.001 In. . TYP CAL PROX MrrY GA~ u'u. sENsmvlrY (IUVI0.001 In.) AG=GATE BASE . 6 IN. D~ SP~CIMEN 0.25 0.001 ~ . DIA SPECII4EN 0.1 0.0006S 5 . 2.1 2.. SIJ - FIAD SOILSAND 0.25 0.0014 2.1 0.25 0.001 2.1 4.0 IN. ~ SPECIM~ 2 8 IN. DIA. SPECIMEN SURGRADE SOIL _ _ _ COHESIVE. 2.8 IN. t)lA. 0.1 1 0.008 1 20 0.1 0.002 1 0 0.1 0.0004 3.5 . SOFT (not. 2) 1 .. 2 -5.0 FRM 2.1 s STlFF- YERY snFF (nots 3) 2.8 (note 4) s NOTES: 1. MINUdUM P`ESILENT DISPUCEMENTS, EXCEPT AS NOTED, ARE MEASURED OYER THE CENTRAL ONE~AU OF A SPCJMH HAVWG A HEJGHr 1 W1CE rRs DUIAETER. CORRECT THIS DiSPLACEMNT IF ANOTHER GAUGE LENGTH IS USED. MINIMUM RESIUEt4T DlSPLACEMEtU GIYEN IS APPROXINIATE AND YARIES ~TH THE MATE~t S TESTED. RESILIENT DISPLACEMNT hIEsSl IRED OVER ENTIRE SPECIMEH i1E~. 3. CONSIDER USING GROUT ED ENDS AND TOP TO BO11OM LYI)TS OR 4.0 In. DIAIUETER SPCIMENS BECA13SE OF POTENTIALLY VERY SMALL DISPLACEI IENTS AT SUALL D\4ATOR STRESSES. 4. P~ MEASURMEN~ SYSTEM TO MAXIbSUM OUTPUT: COt4SIDR EXCEEW40 RECOIlMEHDED VOLTAGE. J O oo l .~ . ~o~7 Figure E-3. Typical cIamps used to measure axial deformation E-9

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Note 6 -- The response of the deformation measurement system shall be checked daily during use. Additionally, the deformation measurement system shad be calibrated every two weeks, or after every 50 resilient modulus tests, whichever comes first. Calibration shall be accomplished using a micrometer with compatible resolution or a set of specifically machined, close tolerance gauge blocks. Resilient modulus testing shall not be conduct if the measurement system do not meet the manufacturer's tolerance requirements for accuracy. 6.4.4 Data Acquisition - An analog to digital data acquisition system is required. The overall system should include automatic data reduction to minimize the chance for errors and maximize production. Suitable signal excitation, condidon~ng, and recording equipment are required for simultar~eous recording of axial load and deformations. The system should meet or exceed the following additional requirements: (~) 25ps A/D conversion time; (2) 12 bit resolution; (3) single or multiple channel throughput (gain-I), 30 kH3; (4) software selectable gains, (5) measurement accuracy of full scale (gain I) of + 0.02%; and (6) nonlinearity GISTS) of ~ 0.5. The signal shad be clean and free of noise (use shielded cables properly grounded). Filtering the output signal during or after data acquisition is discouraged. If a filter is used, it should have a frequency greater than 10 to 20 Hz. A supplemental study should be made to insure correct peals readings are obtained from the filtered data compared to the unfiltered data. A minimum of 200 data points from each EVDT shall be recorded per load cycle. A supplemental study is also suggested to establish the optimum number of data points to use for each specific data acquisition system. 6.5 Specimen Preparation Equipment A variety of equipment is required to prepare undisturbed samples for testing and to prepare compacted specimens that are representative of field conditions. Use of different materials and different methods of compaction in the field requires the use of varying compaction techniques in the laboratory. Specimen preparation is given in Annex Al, specimen compaction equipment and compaction procedures for Type ~ materials in Annex A2 and for Type 2 materials in Annex A3. 6.6 Equipment for trimming test specimens from undisturbed thin-wal1 tube samples of subgrade soils shall be as described in AASHTO T234. 6.7 Miscellaneous Apparatus - This includes calipers, micrometer gauge, steel rule (calibrated to 0.5 mm (0.02 Intel), rubber membranes from 0.25 to 0.79 mm (0.02 to 0.031 in. thickness, rubber O-nngs, vacuum source with bubble chamber and regulator, membrane expander, porous stones (subgrade3, 6.4 mm (0.25 in.) thick porous stones or bronze discs (base/subbase3, scales, moisture content cans and data sheets. 6.8 Periodic System Calibration - The entire system (transducers, signal conditioning and recording devices) shall be calibrated every two weeks or after every fib resilient modulus tests. Daily and other periodic checks of the system may also be performed as necessary. No resilient modulus testing will be conducted unless the entire system meets the established calibration requirements. E-10

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7. Preparation of Test Specimens 7.! The following guidelines, based on the sieve analysis test results, shall be used to determine the test specimen size: 7.~.1 Use 71 mm (2.S in.) diameter undisturbed specimens from ~ walled tube samples for cohesive subgrade soils (Material Type 2~. The specimen length shall be at least two times We diameter (minimum length of 142 mm (5.6 in.~) and the specimen shah be prepared as described in section 7.2. If undisturbed subgrade samples are unavailable or unsuitable for testing, then 71 mm (2.8 in.) diameter molds shall be used to reconstitute Type 2 test specimens. Note 7 -- If 10% or less of a Type 2 sample is retained on the 12.5 mm (0.5 in.) sieve, the material greater than the 12.5 mm (0.5 in.) sieve shall be scalped off and replaced by 9.5 mm to 12.5 mm (0.375 in. to 0.5 in.) material prior to testing. If more than 10% of Me sample is retained on the 12.5 mm (0.5 in.) sieve, the material shall be tested using either 102 mm (4 in.) or 152 mm (6 in.) specimens following previously given criteria. 7. 1.2 Use a split mold 152 mm (6.0 in.) in diameter to prepare 305 mm (12 in.) high specimens for all Type 1 materials with maximum particle sizes less than or equal to 37.5 mm (~.5 in.~. Alternately, 102 mm (4 in.) diameter molds can be used to prepare all Type lb materials having maximum particle sizes less than 25.4 mm (1 in.~. Note ~ -- If 10% or less of a Type ~ sample is retained on the 37.5 mm (1.5 in.) sieve, the material greater than the 37.5 mm (1.5 in.) sieve shall be scalped and replaced by 25.4 to 37.5 mm (~.0-1.5 in.) material prior to testing. 7.2 Undisturbed Subgrade Soil Specimens - Trim and prepare thin-walled tube samples of undisturbed subgrade soil specimens as described in former T234 (now deleted). The natural moisture content (w) of a tube sample shall be determined after tnaxial Mr testing following the procedure T265. Record w in the test report. The following procedure shall be followed for the thin-walled tube samples: 7.2. 1 Standard penetration tests (ASTM D 1586) or cone penetration tests (ASTM D 3441) performed adjacent to thin-walled tube sample locations and elsewhere along the route is encouraged. The results obtained from penetration testing is used to aid in establishing representative subgrade conditions and selecting a representative sample for testing. The sample selected should be of acceptable quality, representative of the subgrade conditions near the surface, and preferably taken from the uppermost tube pushed into the subgrade. 7.2.2 To be suitable for testing, a specimen cut from the tube sample must have a length equal to at least twice its diameter after preparation. The sample must be free from defects that would result in unacceptable or biased test results. Such defects include sampling/trimming induced cracks in the specimen, corners broken off that cannot be repaired during preparation, presence of particles much larger than that typical for the material (for example, + 19.0 mm ~ + 3~4 in.) stones in a fine-grained soil), the presence of foreign objects not representative of the subgrade such as large roots, wood particles, organic material and gouges due to E-11

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A2.3.8 Determine the volume, V, ofthe specimen to be prepared using the diameter determined in step B3.7 and an assumed value of height between 305 and 318 mm (12 and 12.5 inches) for 152 mm (6 inch) diameter specimens and between 203 and 216 mm (8 and 8.5 inch) for 102 mm (4 inch) diameter specimens. A2.3.9 Determine the mass of material, at the prepared water content, to be compacted into the volume (V), to obtain the desired density. A2.3.10 For 152 mm (6 inch) diameter specimens (specimen height of (305 mm, 12 inches)) 6 layers of 2 in. per layer are required; for 102 mm (4 in.) diameter specimens 6 layers of 33.9 mm (1.33 in.) per layer shall be used. Determine the weight of wet soil, WE required for each layer. We= Wit where: W' = total weight of test specimen to produce appropriate density, N = number of layers to be compacted. A2.3.11 Place the total required weight of soil for all lifts, Wad into a mixing pan. Add the required amount of water, Waw and mix thoroughly. A2.3.12 Determine the weight of wet soil and the - mixing p an. A2.3.13 Place the required amount of wet soil (Wry' into the mold. Avoid spillage. Using a spatula, draw soil away from the inside edge of the mold to form a small mound at the center. A2.3.14. Insert the vibrator head and vibrate the soil until the distance from the surface of the compacted layer to the rim of the mold is equal to the distance measured in step A2.3.7 minus the thickness ofthe layer selected in step A2.3.10. This may require removal and reinsertion ofthe vibrator several times until experience is gained in gaging the vibration time which is required. Use a small circular spirit level to assist in keeping each layer level. A.2.3.15 Repeat steps A2.3.13 and A2.3.14 for each new layer after first scarifying the top surface of the previous layer to a depth of about 6.4 mm (1/4 inch). The measured distance from the surface of the compacted layer to the rim of the mold is successively reduced by the layer thickness. The final surface shall be a smooth plane parallel to the base of the biaxial cell. Use the special compaction head shown in Figure A2. I(b) for the final lift. As a final step, the top plate shall be placed on the sample and seated firmly by vibrating with the compactor for about lO seconds. If necessary, due to degradation of the first membrane, a second membrane can be applied to the sample at the conclusion ofthe compaction process. A2.3.16 When the compaction process is completed, determine the mass of the mixing pan and the excess soil. This mass subtracted from the mass determined in step A2.3.12 is the mass ofthe wet soil used (mass of the specimen). Verify the compaction water, ~ of the excess soil using care in covering the pan of wetted soil during compaction to avoid drying and loss of moisture. The moisture content of this sample shall be conducted using AASHTO T265. A2.3. 17 Proceed with Section 8.2 ofthis method. Note ~ - As an alternative for soils lacking in cohesion, a mold with the membrane installed and held by vacuum, as in Annex A2, may be used. E-34

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ANNEX A3 - Compaction of Type 2 Soils (Mandatory Information) A3.l Scope A3. ~ . ~ This method covers the compaction of cohesive Type 2 soils for use in resilient modulus testing. A3. ~ .2 Resilient modulus test results are affected by the spec~men's soil structure. Different type compaction methods impart different soil structures to the specimen. Therefore, the compaction method selected should simulate field conditions. Selection of the compaction method depends upon the field soil moisture at the time of compaction and the later post-construction moisture condition. Either the impact or static method of compaction may be used depending upon moisture conditions. If testable thin-walled tubes are available, specimens shall not be recompacted. E-35 A3. ~ .3 When the range of these conditions are known, specimens may be prepared at specific moisture contents and densities. Select the appropriate compaction method using Table A3. I. If in doubt about the moisture condition, assume the post-construction moisture will be greater than at the time of construction which is usually true. A3.~.4 Impact Compaction - The procedure for impact compaction is described in AASHTO T99 and AASHTO TISO. Upon completion of impact compaction, proceed with Section 8.2 of this test method. A3. ~ .5 Static Compaction - The procedure for static compaction is given in Annex A4.

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ANNEX A4 - Static Compaction (Mandatory Information) A4.! Scope A4.1.1 This method covers the compaction of cohesive Type 2 soils using static compaction. Table A3. I, Annex A3, defines when static compaction is an acceptable method. A4.~.2 A modified version is used of the double plunger static compaction method. Specimens shall be recompacted in a 71 mm (2.8 inch) diameter mold. The process is one of compacting a known mass of soil to a volume that is fixed by the dimensions ofthe mold assembly (mold shall be of a sufficient size to produce specimens 72 mm (2.8 inches) in diameter end 12 mm (6 inches) in height). A typical mold assembly is shown in Figure A4. 1. As an alternative for soils lacking in cohesion, a mold with the membrane installed and held by vacuum, as in Annex A2, may be used. Several steps are required for static compaction as given in Section A4.3 of this Annex and as illustrated in Figures A4.2 to A4.6. A4.2 Apparatus - The apparatus is shown in Figure A4. 1. A4.3 Procedure A4.3. ~ Five layers of equal mass shall be used to compact the specimens using this procedure. Determine the mass of wet soil, We to be used per layer where We = W,/5. A4.3.2 Place one of the spacer plugs into the specimen mold. A4.3.3 Place the mass of soil, WE determined in Step C3. 1 into the specimen mold. Using a spatula, draw the soil away from the edge of the mold to form a slight mound in the center. A4.3.4 Insert the second plug and place the assembly in the static loading machine. Apply a small load. Adjust the position of the mold with respect to the soil mass, so that the distances from E-36 the mold ends to the respective spacer plugs are equal. Soil pressure developed by the initial loading will serve to hold the mold in place. By having both spacer plugs reach the zero volume change simultaneously, more uniform layer densities are obtained. A4.3.5 Slowly increase the load untilthe plugs rest firmly against the mold ends. Maintain this load for a period of not less than one minute. The amount of soil rebound depends on the rate of loading and load duration. The slower the rate of loading and the longer the load is maintained, the less the rebound (Figure A4.2~. Note 2 - Use of compaction by measuring the plunge movements to deter reline that the desired volume has been reached for each layer is an acceptable alternative to the use of the spacer plugs. A4.3.6 Decrease the load to zero and remove the assembly from the loading machine. A4.3.7 Remove the loading ram. Scarify the top surface ofthe compacted layer to a depth of 3.2 mm (~/8 inch) and put the mass of wet soil WL for the second layer in place and form a mound. Add a spacer plug of the height shown in Figure A4.3. A4.3.S Slowly increase the load untilthe plugs rest firmly against the top of the mold end. Maintain load for a period of not less than one minute (Figure A4.3). A4.3.9 Remove the load and flip the mold over end remove the bottom plug keeping the top plug in place. Scarify the bottom surface of layer 1 and put the mass of set soil WL. for the third layer in place and form a mound. Add a spacer ring ofthe height shown in Figure A4.4. A4.3.10 Place the assembly in the loading machine. Increase the load slowly until the spacer plugs firmly contact the ends ofthe specimen mold. Maintain this load for a period of not less than one

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TABLE A3. i Selection of Compaction Method for Laboratory Compacted Specimens i 1 IN-PLACE CONDITIONS Applicable Saturation at Time | Post-Constructi n | Compaction l of Compaction In-Service (GO) Moisture Content Methods <80 less than the moisture content at impact time of construction static >80 greater than or equal to the impact moisture content at time of construction <80 | greater then the moisture at time of construction E-37

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minute. A4.3.~! Follow the steps presented in Figures A4.5 and A4.6 to compactthe remaining two layers. A4.3. 12 After compaction is completed, determine the moisture content of the remaining soil using AASHTO T265. Record this value on Report Form X1.2. A4.3. 13 Using the extrusion ram, press the compacted soil out of the specimen mold and into the extrusion mold. Extrusion should be done slowly to avoid impact loading the specimen. A4.3. 14 Using the extrusion mold, carefully slide the specimen off the ram, onto a solid end plane. The platen should be circular with a diameter equal to that of the specimen and have a minimum thickness of 13 mm (0.5 in). Platens shall be of a material which will not absorb soil moisture. A4.3. 15 Determine the mass of the compacted specimen to the nearest gram. Measure the height and diameter to the nearest 0.25 mm (0.01 inch). Record these values on Report Form XI.~. A4.3.16 Place a platen similar to the one used in step A4.3. 13 on top of the specimen. A4.3.17 Using a vacuum membrane expander, place the membrane over the specimen. Carefully pull the ends ofthe membrane over the end platens. Secure the membrane to each platen using O-rings or other means to provide an airtight seal. A4.3. ~ ~ Proceed with Section B.2 ofthis method. E-38

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(( ~ 2291 ) she ~'b'9~ - Hote: S.D. - Spat DIa~ -Is Shan be See Sted orange ~ Seth) I-D. ~ 8.D. ~ 71.1 men Am) 71.1 mn~l.D. 1 Booth, 7~7 ~ ~10, O.D.I ~ oobr 7t.t mrn ~ I.D. 7~7 - #A ~10 - 60 OLD. 81 t~20- S.SO ) No - : 1` ~ng ~ d den . 1~ m" nry duo ~ a~labJ~ ~ them paw h ~ buy. NOT TO STALE _~ Dla - - .9 mm ~7~ en, ~7 ~ 76 i 1 1 l l 1 1 1. t I 1 1 . add (1) Red ~7~ AS 1 - ma H | Spew no EN Ram (1) Rid ' 1 203. 22S' mm i, oh - - .. ~ ~ - Specer P". Needed H - D~dons ~ dumn on F~6-9or" 2- 100.1 non {3.9W) herald mad by 2 - 71.6 mm 2.820. helg ~bay 2 - 43.2 mm 1.700' height 28~4 mm (1.1Z. a) Figure A4. I. Typical apparatus for static compaction of type 2 materials E-39

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steppes Lifts: COIT pardon ~tO be solid c~lodere of speckled heath' and 70.' mm (2.7~ dear. .. . ~ 2x.~:. ............... ...... . * ..... ......... ........ .......... ........... . . ........... s ~ .. .. ....... .............. ......... ......... . . . ........... ...... ....... ............ .......... ............. ............ ............. ............. ........... ............. . ..... .... .... . . .. .~.~. LJIt 1 Manure ~ wet ma" of HI to use for a layer. place In mold, spade. Insert pIL'gS of gIven height. Double plunge until plows are fl - h who tog arid b=orn ~ mold. Remove~p~- Scarly Me exposed surface of [m 1. Pod web new pep. Figure A4.2. Compaction of type 2 soil, liR I E-40

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Step 3.7 ~ UR 2: Measure ~ wet maw of HI to use for ~ layer. Place In mom, ~e. Hansen 71.6 mm (~8201 pap. Plunge until phases are flush wan top and bosom of mad. FUp mod over arm remove 100.1 mm (3.9W) plug, keeping He 71.~ man (~820' pAq7h placo. By He ted surface d IJft 1 Pad why new asp. . IJft 2 LIft 1 _ 1 Figure A4.3. Compaction of type 2 soil9 lift 2 E-41

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St" 3.. - ~ 3: a.' >:s i. ........ .......... Uft2 lit 1 IJft3 . Manure cod wet weight of ~ to use for ~ layer. Place In mold. spade. Insert 71.8 mm (~ pi-. Plunge unto pled are flush wan top and bottom of mold. Fnp mold over and remove 71.6 nun (2.~) play,, from ~ top d Let 2, keeping Me 71.6 mm ~820~) plug ton Em 3) In place. ~ We exposed surface of Oft 2. Figure A4.4. Compaction of type 2 soil, liR 3 E-42

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Step 3.11 - ~ 4. Measure sorry wet welds of 801 to use for ~ lay - . Phco In mo d, spay. Insert 43~ mm (1.7003 poop. Plunge unfit pings are flush w th top and bosom of mold. Flip mod over and rem~e 71.6 mm ~8201 pay, keeping me 432 An t1.700~ Phil h plans. by ~ ~ ~faos d Lift 3. Proceed Ash new step. _ . : L#t4 lift 2 tat 1 Im3 ,,,,~,~,,,,,,,,,~,..... ........ Figure A4.5. Compaction of type 2 soil' lift 4 . . E-43

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lot 4 left 2 Uft1 1~3 Uft6 I. - Step 3.13 - Lm 5: Measure Wet weight of ~ ~ use for ~ layer. Pi,. Insert 432 mm (1~7008) PIED Plunge until pings are flush web top and bosom of mold. Denude Compacted samp e from mold mIng extruding ah or ex~on mold. Place h rubber menbre`~. . T - tfor Or Figure A4.6. Compaction oftype 2 soil, lift 5 E-44