Frost Resistance of High-Strength Concrete: Dynamic Elastic Modulus as Damage Indicator

Authors: Forschungsinstitut der Zementindustrie, Düsseldorf

Original Language: German (see German version)

Abstract

The durability of external building components depends significantly on frost resistance. Previous laboratory investigations on frost resistance of dense high-strength concrete without artificially introduced air pores have yielded partly contradictory results. The causes of the observed material behavior could not be conclusively clarified. The investigations by the Research Institute of the Cement Industry aim to expand knowledge in order to better evaluate the frost resistance of such concretes. The significance of changes in dynamic elastic modulus as an indicator of internal structural damage in such concretes is systematically clarified. Mechanical parameters such as flexural tensile strength, splitting tensile strength, and static elastic modulus were determined and related to the dynamic E-modulus. It was found that strength decreased due to frost exposure, but this material behavior was not detectable with the dynamic E-modulus. The investigations show that in laboratory testing, silica fume-containing high-strength concrete with an equivalent water-cement ratio of 0.35 or less does not exhibit adequate frost resistance. To what extent laboratory results can be transferred to the practical behavior of concrete is to be clarified in a priority program of the DAfStb.