ASTM C1018-97 PDF Download

The ASTM C1018-97 standard evaluates the flexural performance of toughness parameters of fiber-reinforced concrete. This is achieved by measuring the areas under the load-deflection curve obtained from testing a simply supported beam under third-point loading.

The standard provides a method for determining toughness indices, which are ratios obtained by dividing the area under the load-deflection curve up to a specified deflection criterion, by the area up to the deflection at which the first crack is deemed to have occurred. These indices help identify the pattern of material behavior. Residual strength factors, representing the average post-crack load retained over a specific deflection interval as a percentage of the load at first crack, are derived from these indices.

The test method also includes determining the first-crack flexural strength using the load corresponding to the point on the load-deflection curve defined as the first crack. The formula for modulus of rupture given in Test Method C78 is used for this determination.

Values provided in inch-pound units for flexural toughness and first-crack flexural strength are considered standard. However, values of toughness indices and residual strength factors are independent of the system of units used to measure load and deflection.