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California Test 301 1978 E. PRECAUTIONS should im-lude a standardized roughness in order to 1. In feeding the material into the nao!d from the maintain the 11-value scale at a level similar to the tratigh, it is quite important that the operator exc•- original findings. The specification of 250 micro cull! this furtctiaat in a uniform nt:innrr. Tests have inches, in accordance with the standard Ceneral shown that differences in compactive efforts can Electric roughness scale, is primarily intended to cause variations in rewilts obtained front the cxud:t- give the mold fabricator a "target" value to world tion device (Part 111)when certain typesof materials towards. In actuality, R-value results obtained with are tested. As an aid towards uniforn feedings,it is given molds.ire not critical to the absolute values or suggCAL11 that the 20 increinents specified in Part degree of roughness.The iinportarit point is that the 1I•D•3 be indicated oil the edge of the trough with molds should be rough textured as compared to those permanent scribe marks. which are smooth and have almost "mirror like" 2. Even distribution of Ilse coarse .igq.cgatce finishes. throughout the length of the feeder trough is impar- G. HAZARDS tant in order to avoid segregation in the coinpacted Caution must he exercised in the operation of the speciinem• The material should be evened out and compactor so as not to allow any object oper ether than th eied manually star the fingers or spatula alone the sample itself to intercede between the cornpac- thc trough before starting the feeding operations. for foot and the mold at any time while the ram is in 3. it is important c resent the basket by hand, inotion. The clearance between the inside edge of but the mold clearance adjustment (lection Risk o the mold and the compactor foot is approximately%,s tearibut before starting compacting operations. fico of inch. The appiied shearing force of 1,100 pounds basket, tapes,which attach the bronze disc to rin Could cause severe injury to an operator's handl if sestet,is taken if compaction y started without fire caught between the compactor foot and the mold.A basting of the basket assembly on the mold holder clear plastic guard has been designed for the Califor- a. Do not use any more tape than is shown in base. riia compactor and should be used as an aid in safe- Figure Figure 5-U when securing Phosphor bronze disc to guarding against this hazard. basket. PART III. METHOD OF DETERMINATION OF F. VOTES EXUDATION PRESSURE OF R-V.aLUE While the use of baskets for aggregate bases is TEST SPECIMENS . mandatory (Section D•12),the decision whether to A. APPARATUS use baskets on other materials must he based on ex- perience. They should not be used if they :are riot 1. Moisture exudation indicating device (Figure needed, If baskets are not used and the specimett 7). breaks up while being transferred into the stabiloinc- 2. Disc, Phosphor bronze, with perforated edge, ter(Part V) the fact may not be apparent at the time, 3'%32-inch diameter and 28-gauge (Figure 8). but it will result both in excessive stabilometer Pres- 3. 10,(W-pound c pacity testing machine. sure readings and in cxcess'it c dnPLICO OW re:rti_ a. Follower ram,3.950 = .005-inrh outside diarne- ings.Both of these errors wid to lower the R-value, ter x 3 inch long. and a group of three tests will be erratic with respect to one another.When this happens the test roust be reputed using baskets. With reference to mold roughness,specified(under Apparatus,it has been found that the character of the inside surface of the mold will influence the exuda- tion pressure phase of the test and consequently the 11-valve obtained at 3W psi eructation pressure. In general,smooth molds%vill result in sonar%hat high- ; er R-vahacs at 300 psi exudation pressure titan will A • those with a roualtCr surface. Since the original developit:ental studies for ih-_ 11•v:111e test involved the use of molds Ila ing a FAWN' rough texture, the mam,factury of additional units �flfiURE 7 10