70 years of measuring air content ­according to Boyle-Mariotte

It has been known since the 1940 s that deliberate air entrainment increases the frost and freeze-thaw resistance of hardened concrete. This is why the air content of fresh concrete and its correlation with the air content of hardened concrete must be determined prior to concrete pouring. Following the exclusive application of the volumetric measurement method (“rolling method”) in the early years, Klein published the option of measuring the air content of concrete by applying Boyle-Mariotte’s law and presented the first “pressure air meter”.

This device served as a basis from which Type A with...

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