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Section 3: Aggregate testing and the use of alternative aggregates |
Geomaterials Research Services Limited, 1 Falcon Park, Crompton Close, Basildon, Essex SS14 3AL, UK
This paper briefly introduces the basis of abrasion testing and suggests a rapid and simple test that allows the abrasion resistance of specific materials to be evaluated. Small, individual pieces of rock, mortar, or concrete can be tested and the method has been used to evaluate the potential for surface abrasion of concrete surfaces. Many of the commonly used test methods for measuring abrasion resistance of construction materials are aggregate tests such as the QMW mill abrasion test and the ASTM Los Angeles abrasion test which measure the combined resistance of a material to impact and abrasion. Other tests such as the aggregate abrasion and polished stone value tests require a smaller numberof resin mounted aggregate pieces to be studied. The ASTM surface abrasion test for concrete uses physically large flat test pieces. Like the ASTM test, the test method described in this paper measures only the abrasion resistance. However, it provides a means of comparing the abrasion resistance of small pieces of construction material and introduces quartz as a reference material.
The test uses a mixture of oil and carborundum as a grinding medium with 10 mm square test pieces held by a standard load against a rotating steel lapping wheel in a rotating jig. The results are expressed as a ratio of the abrasion rate of the test material to that of quartz tested in the same way. This comparative approach enables the test to be carried out using equipment of various designs.
