TESTING PROCEDURE OF HIGHWAY MATERIALS / VARIOUS TESTS OF HIGHWAY MATERIALS.
TESTS ON HIGHWAY MATERIALS:
1.MCV Test
2. California bearing ration (CBR) test
3. Dynamic cone penetrometer test
4. Ground penetrating radar test
5. Los Angles Abrasion test
There is a relationship between compacting effort, moisture content and density. The MCV test involves testing a soil at fixed moisture content and by increasing the number of blows of a rammer, determining the compactive effort beyond which no further increase in density occurs. As a general guide MCV of 8.5 is recommended as the lower limit of acceptability of a soil for compaction at its natural moisture content and difficulties in earth working can be expected when MCV drops significantly below this value.
California Bearing Ration (CBR) Test:
The CBR test involves the insertion of a 50mm diameter plunger into the ground surface at a rate of 1mm per minute, whilst the load is recorded. Surcharge rings can be placed around the plunger to simulate an overburden. The load at penetration of 2.5 and 5mm is compared with the result from a standard aggregate and the ratio given as a percentage.
Dynamic Cone Penetrometer:
A standard concrete is hammered through the unbound layers of a pavement using a standard effort from a falling weight. These lower layers of the pavement are typically accessed through a core hole. The number of blows per unit of penetration is recorded and relate to the shear strength of the material. Calibration allows either this parameter or the CBR to be determined.
Ground Penetrating Radar (GPR):
From GPR test in addition to the thickness profile we can know about areas of high moisture, voiding, and joint condition.
Los Angles Abrasion Value Test:
The Los Angles Abrasion test is to indicate the resistance to abrasion. Percentage of fines passing through the 1.7mm sieve is measure of Los Angles Abrasion Value. If its value is over 40% then the material is quite soft. If it is 25% then the material is hard.
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