Determining the Resistance R-Value for a compacted soil or aggregate sample is a testing requirement of ASTM D2844, AASHTO T190, and CTM 301. The purpose of the test is to determine the suitability of the material for use under paved roads and airway surfaces. The cylindrical sample is placed in a Hveem Stabilometer device and then compressed. The stabilometer measures the horizontal pressure that is produced while the specimen is under compression.
The test procedure requires loading the sample in compression while inside the stabilometer. The compression tester must allow for the entire stabilometer device and following ram to fit inside the compression test space. During the test, the operator must record horizontal pressure readings from the gauge on the stabilometer at specified compressive loads - this often requires 2 operators. The technician must also turn a crank handle that moves a displacement turns gauge on the stabilometer. The turns gauge value is recorded for use in the calculation of the R-value.
To perform this test, we supplied a model 300DX compression-only test machine with Partner™ testing software. The Partner Gentest application package allowed for proper test control, and automatically prompted the operator when to take stabilometer readings - eliminating the need for a 2nd operator. The R-value calculation result was automatically generated from the variables input by the user and the load values are recorded by the Partner software. The large test space and special table extension permitted the stabilometer to move easily in and out of the test space.