CSA A23.2-19-4C - Air content of plastic concrete by the pressure method скачать в хорошем качестве

CSA A23.2-19-4C - Air content of plastic concrete by the pressure method

The primary purpose of the plastic concrete air test is to confirm that the concrete supplied to the jobsite has been air entrained to provide freeze-thaw durability. The pressure method of air content determination is applicable to normal and high density concretes where the raw materials used in the production of the concrete do not contain significant voids that could affect the test results. Low density and porous aggregates require air testing via the volumetric method (CSA A23.2-7C) and should not be tested using the pressure method. Plastic air tests are also performed whenever concrete strength cylinders are obtained. This requirement applies to non-air entrained concrete since the air content can have a significant effect on both concrete strength and the ability of the concrete finisher to finish the concrete slab without surface defects. For non-air entrained concrete the expected amount of air is typically in the 3%+ range.