Testing of zero-slump piling concrete

For several years it had been noted in the field that in the absence of an accepted, rational standard method for testing impact-placed zero-slump piling concrete, a variety of strength levels were produced from the same sample of fresh concrete depending upon which of a variety of test methods happened to be used. Finally, in 1977 the Canadian Standards Association published a standard method. This method subsequently proved ambiguous and impractical in practice to many field engineers.This paper presents the results of a laboratory and field study conducted during 1985 directed at the rational development of a practical test method to realistically predict the appropriate concrete strength, [Formula: see text], to be used in the calculation of the structural load-carrying capacity of this type of pile. Key words: zero slump, impact piles, energy input, vibration, compaction, concrete strength.