1. Application

This applies to test method of green sand compression strength.

2. Definition:

Green sand compression strength is defined as the load divided by the specimen cross section at breakage of a standard specimen on compression by the method described below.

3. Instrument:

3.1 Compression test machine

A test machine is used that is capable of compressing and breaking specimens at an approximate loading speed of 0.3N/cm² per second.

3.2 Checking

The instrument and apparatus used in the test are checked at an appropriate interval to maintain the necessary precision.

4. Testing procedure

4.1 Specimen preparation

Test specimens are prepared by the method of TJFS-101 (Preparation of standard green sand specimen). The sand forming a specimen should not be reused in another test.

4.2 Operation

A test specimen is placed on the machine and is given compression a loading speed of 0.3 N/cm² per second. The load at breakage is measured.

5. Expression

Compression strength is expressed in N/cm2. If the load is expressed in weight kg, the compression strength is obtained by the following equation.

\[\sigma c = {W \times 9.8 \over A}\]
where

\[ \left\{ \begin{array}{l} \sigma c &= compression \ strength(N/cm^2) \\ W &= load \ at \ breakage(kg) \quad Note:N=9.8×kg \\ A &= specimen \ cross \ section =19.6 (cm^2) \end{array} \right. \]

6. Record

The test result is calculated to the second decimal place. Tests are repeated three times or more from the same batch of sand and average value is calculated from results within ±5% of standard deviation.