ASTM C198-09 (R2019) PDF Download

ASTM C198-09 (R2019) is a standard test method that is used to determine the cold bonding strength of refractory mortar. The purpose of this test is to measure the bonding strength and intrinsic strength of different qualities of air-setting mortar when used in conjunction with specific brands or lots of refractory brick. The test method provides procedures for determining the flexural strength (modulus of rupture) of oven-dried brick-mortar joints at room temperature.

It is important to note that the results obtained from this test method can indicate the compatibility of brick and mortar combinations for use at high operating temperatures. However, it is the responsibility of the user to determine the compatibility for a specific application. Only brick and mortar combinations that are known or intended to be compatible for a particular use should be tested.

The properties of the brick, including strength, apparent porosity, and pore size distribution, can impact the measurement of both the bonding strength of the brick-mortar composite and the intrinsic strength of the mortar. Therefore, it is recommended to test specific brands or lots of brick and mortar to ensure accurate results.

The test method allows for three modes of failure: within the brick itself, at the brick-mortar interface, or within the mortar itself. The predominant mode of failure with the four-point flexure test is within the mortar itself, providing a practical measurement of the mortar strength. Failure within the brick suggests either the presence of a serious flaw in the brick or that the mortar joint strength is equal to or greater than that of the refractory brick. The mode of failure should always be reported in the final test report.

This test method has been ruggedness tested, and variables such as specimen size, mortared surface, joint thickness, pulling of rods, loading rate, method of load application, and the operator have been found to be rugged. The cold bonding strengths obtained using this test method are suitable for various applications such as research and development, quality control, and establishing compliance with specifications between producers and consumers.