Measuring The Compressive Strength Of Concrete To Bs En 12390-3

摘要

Recent developments in the European Standard for measuring the strength of concrete, BS EN 12390-3(1)', have increased the allowable rate of loading range to 0.2-1 .OMPa/sec. This paper examines the effect of this, and any future relaxation of the rate of loading, and determines whether the variability in measured strength remains within the required repeatability of the test.rnConcrete producers measure strength to ensure compliance with the specified compressive strength requirements. It is established that the measured values increase with increasing loading rate. The magnitude of this effect may vary with concrete strength class, machine calibration, planeness of bearing surfaces and positioning of test specimens within the machine, as well as the degree of saturation of the test specimen, and constituent materials. Aggregate type has also been found to influence the measured strength, with aggregates of lower stiffness being more sensitive to an increase in the rate of loading.