ASTM C642:13 pdf free download – Standard Test Method for Density, Absorption, and Voids in Hardened Concrete.
7.1 Assume a sample having the following characteristics:
7.1.1 Mass of the solid part of the specimen = 1000g.
7.1.2 Total volume of specimen (including solid.”pernieable” voids, and “impermeable” voids) = 600 cm3.
7.1.3 Absolute density of solid part of specimen = 2.0 MgI
7.1.4 Void space in specimen contains initially only air (no water).
7.2 Then, it follows that there are 5(X) cm ‘ of solids and 1(X) cm3 of voids making up the specimen, and the void content is Vs =16.67%.
7.3 Assume that on immersion 90 mL of water is absorbed.
7.4 Assume that after immersion and boiling 95 niL of’ water is absorbed.
7.5 Based on the assumptions given in 7.1-7.4 above, the data that would be developed from the procedures given in Section 5 would be as follows:
7.5.1 Oven-dry mass. A = 1000 g.
7.5.2 Mass in air after immersion, II = 1090 g.
7.5.3 Mass in air after immersion and boiling, C = 1095 g.
7.5.4 Apparent mass in water after immersion and boiling. D = 495 g.
Nun I—Since loss of miss in water is equal to mass of displaced waler, and volume of specimen = 6tX) cm. mass of specimen in waler after immersion and boiling is 1095 — 600 = 495 g.
7.6 By using the data given above to perform the calculations described in Section 6, the following results will be obtained (Note 2):
Note 2—This test method dues nut involve a determination of absolute density. Hence, such pore space as may be present in the specimen that is not emptied during the specified drying or is not tilled with water during the specified immersion and boiling or bu(h is considered “impermeable” and is nut differentiated from the solid portion or the specimen for the calculations, especially those ror penent voids. In the example discussed it was assunied that the absolute density of the solid portion of the specimen was 2.0 Mg/m’. the total void space was 16fi7 . and the impenneable void space was 5 cm’. The operations. if performed. and the calculations. i1 performed as described, have the effect of assuming that there are 95 cm’ of pore space and 505 cm’ of solids, and indicate that the solid material. therefore, has an apparent density of 1.98 rather than the absolute density of 2.0 Mg/m3 and the specimen has a percentage of voids of l58 rather than l667.
Depending on the pure sue distribution and the pore entry radii of the concrete and on the purposes tor which the test results arc desired, the procedures of this test method may he adequate. or they may bc insufficiently rigorous. In the event that it is desired to till more of the pores than will he filled by immersion and boiling, various techniques involving the use of vacuum treatment or increased pressures may be used. If a rigorous measure of total pore space is desired, this can only be obtained by determining absolute density by first reducing the sample to discrete particles, each of which is sufficiently small so that no impermeable pore space can exist within any of the particles. If the absolute density were determined and designated g.