If you only measure absorption by soaking (per ASTM C1585, the "sorptivity" test), you miss the deep, inaccessible pores that later become reservoirs for dissolved chlorides. C642 finds everything that can possibly get wet.
Here is where the story gets subtle. ASTM C642 cannot tell the difference between good voids and bad voids.
The precision and bias of the test method are as follows: astm c642 density absorption voids in hardened concrete
This test method covers the determination of:
The story of ASTM C642 is not one of lasers or X-ray diffraction. It is a story of boiling water, oven heat, and a scale accurate to 0.01% of the sample’s mass. It is elegantly simple, brutally effective, and surprisingly easy to mess up. If you only measure absorption by soaking (per
ASTM C642 is a widely used standard test method for determining the density, absorption, and voids in hardened concrete. This test method is essential for evaluating the durability and performance of concrete structures, as it helps to identify potential issues with the concrete's composition, placement, and curing.
Note: Values >20% permeable voids generally indicate poor-quality concrete or a mix design error. ASTM C642 cannot tell the difference between good
Here is how the test unfolds in a typical materials laboratory.
ASTM C642 is the internationally recognized standard for determining the in hardened concrete . This test method provides critical data for assessing concrete quality and predicting the long-term durability of structures. Importance of ASTM C642 Testing
ASTM C642 is a widely used standard test method that provides a simple and reliable way to determine the density, absorption, and voids in hardened concrete. The test method involves measuring the mass of a concrete specimen in air and then in water to calculate its density. The absorption of water by the concrete specimen is also measured, which helps to estimate the volume of voids in the concrete. The results obtained from this test method are crucial in assessing the quality and durability of hardened concrete.