Methods for Determining Abrasion Resistant Of Concrete

There are different test methods to determine the abrasion resistance of concrete, subjected to a variety of abrasion. There are different tests used in different countries and it is apparent that there is no single method that sufficiently measures the abrasion resistance of concrete under all conditions.

Different types of abrasion tests which are listed below.

• Method for abrasion resistance of horizontal concrete surface
• Method for abrasion resistance of concrete by sand blasting
• Method for testing and obtaining drilled cores and sawed beams of concrete
• Method for abrasion resistance of concrete underwater method

Currently, there are four standard test methods conducted at International level. A tabular guide should be used to illustrate the aptness of each process in different abrasive materials. Theses guides are very useful to the researchers in deciding the type of test required to simulate the field of abrasion conditions. The consistency of test methods for abrasion resistance of concrete surface can be used for various purposes. The methods   used worldwide to evaluate the abrasion resistance of concrete, have attempted with varied success to imitate the typical forces harmful to concrete surfaces.

Testing Procedures and Methods:

A brief detail of these important methods are as follows:

• Method by Sand Blasting: This technique is based on the principle of producing abrasion by sandblasting. This process imitates the appearance of waterborne abrasives and particles on concrete surface. Controlling the type of abrasive and pressure allows the engineers to differentiate between the severities of abrasion. The blast area is equipped with an injector type blast gun and high speed air jet. The different parameters such as air pressure, gradation of sand, rate of feed and abrasive charge separates the nozzle from the surface.
• Method for testing and obtaining drilled cores and sawed beams of concrete: This process is used for determining the abrasion resistance of concrete by sawed beams and drilled cores. The concrete gives an indication of the comparative abrasion resistance of mortar and concrete based on testing of fabricated of cored samples. This method can also be used for other abrasion resistant materials such as ceramics and few metals. The testing equipment contains drill press and rotating cutter. The main complexity in maintaining a stable weight on the abrading cutter when using the lever, gear and spring system of a drill press can be eliminated by insertion of a constant load directly on the spindle that turns the cutter.

• Method for Horizontal Concrete Surfaces: There are three main types of processes in the standard technique for abrasion resistance of horizontal concrete surfaces.

Revolving disk machine: This machining method introduces frictional forces by grinding and rubbing. Scuffing and Sliding is accomplished by rotating steel disks in combination with abrasive gravel.

• Ball bearing machine: In this method, the machine operates on the principle of a sequence of eight ball bearings rotating below a heavy load and at a speed of 1500 rpm (rotations per minute) on wet concrete test surface.
• Dressing wheel machine: This method is very similar to revolving disk machine; except it has three sets of six dressing wheels mounted on parallel shafts and are joined with the three rotating steel disks.

These methods are very adaptable and portable for laboratory and on site field abrasion testing.

Test Method for Abrasion Resistance of Concrete Underwater Method: This method is also used for abrasion resistance of concrete. It was developed by Liu in 1981 for measuring the abrasion action of any abrasion resistant material. It was also used to determine the accurate resistance of concrete subjected to water particles on hydraulic structures such as spillways, stilling basin etc.

The equipment contains basically an agitation paddle, a drill press, a cylindrical steel container and 60 steel grinding balls of different sizes.

The container filled with water is circulated by the captivation of agitation paddle that is motorized by drill press rotating at a speed of 1100 rpm.  Circulating water container in turn, moves the abrasive charges on the surface on the concrete specimen, generating the abrasion effects. The standard test consists of six 10 hours test periods for a total of 60 hours.