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.x Rhe. ix California Tait 365 January, 141tS r4� cal properties of each test specimen.This is F. PRECAUTIONS yl a normal part of the test and 110 attempt to 1. Hvej, effort should be made to fabricate test maintain a rate of loading of oM per minutes specimens having an overr,il height between 2.40 throughout the test should be made.) inches and 2.60 inches;however,if for some reason f. Stop the vertical loading exactly at 6,000 lbs, this is not possible, the stabilometer value should be corrected as indicated on the attached chart, and immediately reduce the load to 1,000 l00 lbs. Using the displacement pump; figure 4. reduce the horizontal pressure to 4 psi,This 2• Adhere strictly to the temperature control re- will result in a further reduction in the verb- quirements. cal load which is normal and for which no 3. Frequent calibration of the stabilometer should compensation is necessary,Raise the pressure be made during the day as temperature change has to 5 psi and set the turns displacement indica- considerable effect upon the pressure exerted within top dial zero. Turn the pump handle at the hydraulic system. This is especially true when approximaa tely hvo turns per second until the changing from R-value testing to bituminous testing. stabilometer gauge reads 100 psi. (During this operation the vertical load 4. Close adherence to the 5 psi initial horizontal registered on the testing machine will in- pressure is necessary for accurate test results. crease and in some cases exceed the initial S. When setting the 5 psi horizontal pressure,al 1,000 lb load.As before,these changes in test- ways drop below 5 psi,and then bring the pressure ing machine loading are characteristic and no back up to 5 psi,and gently tap the dial to remove adjustment or compensation is required.) any slack in the dial indicator gear. g. Record the number of turns indicated on the 6• The head of the press must be free-acting and dial as the displacement of the specimen. spherically-seated with the ability to conform to the The turns indicator dial reads in 0.001 in.,and surface plane of the test specimen. each 0.1 in.is equal to one turn.Thus a read- 7, After each test,use a clean dry cloth to wipe the ing of 0.250 in,indicates that 2,50 turns were diaphram prior to proceeding with another test. If made with the disp!acement pump. This the diaphram.feels sticky after wiping,dust it lightly measurement is known as "turns displace- with a fine powder such as talcum powder or equiva- ment"of the specimen. lent. 2. Calculation of stabilometer values. G. REPORTING OF RESULTS r a. S = -2 Report the results of the stabilometer test as the [PI,XDI(Pv—Ph)I +0.222 numerical value obtained as shown under"Calcula- tions". This value represents the relative resistance Where: to lateral deformation on a scale ranging from 0 to 5=stabilometer value 1r0 Ph= horizontal pressure for correspond- - ing py (psi) REFERENCES D displacement of specimen, (turns) California Test 367 P„= vertical pressure (typically 400 psi). End of Test is pRs) onn Calif.a366 b- The attached conversion chart, Figure 3, is normally used to solve the above formula. �� 3