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The guideslecse shall be held steady :cod
<br />wuhm 5 deg of the eerucal. Apple the hlaw,
<br />at a uniform rate nut exceedine approximate h•
<br />I A s per blow and m such a manner as to
<br />pro+ide complete cot eraee of the specimen
<br />surface.
<br />4.2.2 Following compaction. rcmoyc the
<br />rxtemiun collar, carefully trim the compacted
<br />specimen even with the top of the mold by
<br />means of the straightedge and determine the
<br />mass of the specimen. Dis ide the mass of the
<br />compacted specimen and mold, minus the
<br />mass of the mold, by the volume of the mold
<br />(see 3.1.3). Record the result as the wet
<br />density, yin, in pounds per cubic foot (or
<br />kilograms per cubic metre) of the compacted
<br />specimen.
<br />42.3 Remove the material from the mold.
<br />Determine moisture content in accordance
<br />with Method D 2216, using either the whole
<br />specimen or alternativeh~ a represenlutivc
<br />specimen of the whole speamen. The whole
<br />specimen must be used whin the permeahdiry
<br />of the compacted specimen is high enough xt
<br />that the moisture cumem is not dislnhutcd
<br />uniformly throughout. If the schole specimen
<br />is used, break it up to fanlrt:nr drying. OMmn
<br />the re pre sentatise specimen by slicing the
<br />compacted spa'imrn axially through the cen-
<br />Ier and removing 701) to 5U(1 g of material
<br />Irom one of the cut faces.
<br />4.2A Repeat 4.2 through 42.3 lur each
<br />specimen prepared.
<br />5. Oversize Corrections
<br />5.1 II 30 % or inure of the sample u
<br />retained on a '/,-in. (19.0-mm) slue, then
<br />none of the methods described under these
<br />methods shall br used fur the determination
<br />of enher maximum density or optimum nwis-
<br />ture content.
<br />5.2 Met/roda A turd B-The material re-
<br />tained on the No. 4 (4.75-mm) sieve is dis-
<br />carded and no oversize correction is made.
<br />However, it is recommended that if the
<br />amount of material retained is 7 S'o or create r,
<br />Method C be used instead.
<br />5.3 Method C-The material retained on
<br />[he '/.-in. (19.0-mm) sieve is discarded and
<br />no oversize correction is made. However, if
<br />the amount of material retained is 10 % or
<br />greater, it is recommended that Method D be
<br />used instead.
<br />5.4 Merhod D:
<br />5.4.1 Thia merhod shall not be used unless
<br />the amount of material retained on the '/.-in.
<br />(19.0-mm) sieve is 10 % or greater. \Vhen
<br />the amount of material retained on the'/.-in.
<br />sieve is less than 10 %, use Method C.
<br />5.4.2 Pass the material retained on the t/4-
<br />in. (19.0-mm) sieve through a 3-in. or 75-mm
<br />sieve. Discard the material retained on the T-
<br />in. sieve. The material passing the 3-in. sieve
<br />and retained on the t/<-in. sieve shall be
<br />replaced with an equal amoun[ of material
<br />passing a'/a-in. sieve and retained oq a No.4
<br />(4 75-mm) sieve. The material for replace-
<br />ment shall be taken from an unused portion
<br />of the sample.
<br />6. Calculations
<br />6.1 Calculate the moisture content and the
<br />dry density of each compacted specimen as
<br />follows:
<br />w = [U - BIJ(B - C)] r. 100
<br />and
<br />y„ _ [y,,,/bv + 100)[ x 100
<br />where:
<br />w moisture content in percent of the com-
<br />pacted specimens.
<br />A = mass ofcontainer and moist specimen,
<br />B =mass of container and oven-dried spec•
<br />amen,
<br />C mass of container,
<br />ya =dry density, in pounds per cubic foot (oi
<br />kilograms per cubic metre) of the com•
<br />parted specimen, and
<br />y,,, .= w'et density. in pounds per cubic foot
<br />(or kilograms per cubic metre) of the
<br />compacted specimen.
<br />7. Moisture•Density Relationship
<br />ZI From the data obtained in 6.1, plot i
<br />dry densit}' values as ordinates with cot
<br />sponding moisture contents as abscissas. DI
<br />a smoo[h curve connecting the plotted poi
<br />Also draw a curve termed the "curve oCu
<br />plete saturation" or "zero air voids curve"
<br />this plot. This curve represents the relations
<br />between dry density and corresponding m~
<br />tore contents when the voids are complel
<br />filled with water. Values of dry density i
<br />corresponding moisture contents for plot)
<br />the curve of complete saturation can be u
<br />204
<br />puled using the following equation:
<br />w~„ _ [(6?.4/y„1 - lt(G,1) x tau
<br />where:
<br />w,,,, = moisture content in percent for com-
<br />plete saturation,
<br />y,r = dry densely in pounds per cubic foot
<br />(or kilograms per cubic metre).
<br />G, = specific gravity of the material being
<br />tested (see Note 4), and
<br />62.4 density of w:ner in pounds per cubic
<br />foot (or kilograms per cubic metre).
<br />Nore 4-The specific gravity n(the mate sal can
<br />either he auumed or b:ued on the weighted a+c rage
<br />values nC (n) the specdic grrvny of the material
<br />passing the No. 4 (4.75-mm) sieve in accordance
<br />wnh Method D 854; and (h) the apparem specific
<br />gravity of the material retained on the Nn. 4 +icvc
<br />m accordance with Method C I?7,
<br />7.2 Optimum Mounter Col»rru, n-„-The
<br />moisture content corresponding to thz pr;ik
<br />of the curve drawn ^s directed in 7.1 sh:dl br
<br />termined the "optimum moisture contem ."
<br />7.3 Ma rimu»r Den.rin , y,,,,, -The dn' den-
<br />sity in pounds per cuhir (ors (or kilograms per
<br />cubic metre) of the sample m "optimum mois-
<br />ture content" shall he termed "maximum
<br />density."
<br />8. Report
<br />8.1 The report shall include the following.
<br />TABLE I Volume or water per Greco based an
<br />Temperature'
<br />Temperature. °C (°F) Volume of Wairr, ml/g
<br />12 (57.6) 1.00048
<br />14 (57.2) 17%1077
<br />16 (60.8) 100107
<br />r 18 (64.4) 1.00178
<br />20 (66.0) 1.00177
<br />22 (71.6) 1.00221
<br />24 (75.2) 1.00268
<br />36 (78.8) 1.00720
<br />28 (82.4) 100775
<br />70(86.0) Ll10aJ5
<br />72 (69.6) 1.00497
<br />"Values other than shown mu} be oMuined by refe wing
<br />b the HandhooA of Chem inry and Phrnrs. Chemical
<br />,Rubber Publishing Co.. Cleveland. Ohio.
<br />205
<br />8 I.I Method cord (Method :\. B. C ul
<br />D ).
<br />8.1 ? Optimum moisture content.
<br />8 I ..i Maximum density'.
<br />g.l .4 Description of rummer (whether
<br />manual or mechanical).
<br />8.1 .5 Description of appearance of mate-
<br />rial u+ed m test, hosed on Recommended
<br />Practice D 2488 (Cla++ification D ?487 may
<br />be used as an alternative).
<br />8.1 .6 Origin of mulct ial used in test.
<br />8.1.7 Preparation procedure used (moist
<br />or dt v).
<br />9. Precision
<br />9.1 Cnteri^ (or judging the acceptability of
<br />the masimum densuv and optimum moisture
<br />Content test rc+ult+ arc eivcn m Table ?. The
<br />standard deviation, s. is c:dculated from the
<br />eyuauon:
<br />
<br />when.
<br />n = number of determinations.
<br />x = individual value of each determination,
<br />and
<br />.c = numerical average of the determinations.
<br />lions.
<br />9 2 Criteria (rn amigmng st:mdani devia-
<br />ti~n v;ilue+ (oi single-ope r;unr precision ;ire
<br />not av;iilable m the pre+ent time.
<br />TABLE 2 Dry Preparelian Melhad -Standing Times
<br />Classification D 248] Minimum Standing Time,
<br />n
<br />G w', GP, aW, SP nn reywremem
<br />GM.SM 7
<br />ML,CL,OL. GC. aC IB
<br />MH. CH, OH. PT J6
<br />
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