ASTM C1040/C1040M-16a PDF Download

The ASTM C1040/C1040M-16a standard provides guidelines for nondestructive testing of the density of both unhardened and hardened concrete. The test methods described in this standard are based on gamma radiation and are rapid and efficient.

This standard includes two test methods: Test Method A, which is the Direct Transmission method, and Test Method B, which is the Backscatter method. The Direct Transmission method is used for determining the density of unhardened concrete, while the Backscatter method is employed for both unhardened and hardened concrete. The fundamental assumptions for these test methods are that Compton scattering is the dominant interaction and that the material under test is homogeneous.

These test methods have various applications, including controlling and accepting testing during construction, evaluating the quality of concrete after construction, and facilitating research and development. However, it is important to note that these methods should be used with caution when monitoring the degree of consolidation, as the density measurement obtained may vary due to the variability of concrete components.

The test results may be affected by factors such as reinforcing steel, chemical composition of concrete constituents, and sample heterogeneity. However, these variations can be minimized through instrument design and adherence to the appropriate sections of the test procedure. Additionally, the Backscatter method may be affected by the density of the underlying material, and the sensitivity of the apparatus decreases with distance from the surface of the concrete.