TEST METHODS COMPARATIVE STUDY OF CONCRETE RESISTANCE AGAINST FREEZE-THAW CYCLES AS DESCRIBED IN CEN/TS 12390-9, ISO-DIS 4846-2 AND NTN-018 Lucie VANDEWALLE Professor, department of civil engineering, Katholieke Universiteit Leuven, Belgium Winne FIGEYS Doctor assistant, Katholieke Universiteit Leuven, Belgium Christian PIERRE Head of research department, Cement Industry Research Centre, Belgium Olivier GERMAIN Researcher, Cement Industry Research Centre, Belgium Olivier DE MYTTENAERE Technical advisor, Belgian Road Research Centre Anne BEELDENS Researcher, Belgian Road Research Centre ABSTRACT: Resistance to freeze-thaw cycles is an important factor for the durability of concrete for roads and structures in an outdoor environment. Since August 2006, new methods are introduced in a European Technical Specification CEN/TS 12390-9. This necessitates a comparative study of the test methods described in it, not only between them, but also with the methods used in Belgium. Method-specific acceptance criteria for concrete, as well as criteria to make a choice of the most suitable method in relation to the type of concrete need to be put in place. Therefore a joint prenormative research project has started as collaboration between the Cement Industry Research Centre (CRIC), the Belgian Road Research Centre (BRRC), and the Katholieke Universiteit Leuven (KUL). This project evaluates the five different test methods and compares the results obtained on different types of concrete. Keywords: frost-thaw test method, scaling resistance, air entrainment 1. INTRODUCTION Frost-thaw resistance in the presence of de-icing salts is especially for road applications a main issue. In order to obtain durable concrete, specific demands are put forward on the composition of the concrete mixtures (cement content and water/cement ratio) as well as on the air entrainment. Since August 2006, a European Technical Specification CEN/TS 12390-9 is introduced in which three different methods are proposed to verify the frost resistance of concrete constructions [1]. The three methods which are proposed are: - the slab test – introduced as reference method - the cube test as alternative method - the CF-CDF test as another alternative method – without and with de-icing salts. To introduce this methods in a proper way it is not only necessary to determine the most suitable method but also to put in place limits in relation to the application categories to indicate the levels of cumulated mass loss. Therefore, a research programme has started in Belgium, as a joint project between the Belgium Cement Industry Research Centre (CRIC), the Belgian Road Research Centre (BRRC) and the department of civil engineering, construction materials of the Katholieke Universiteit Leuven (KUL). A comparison between the actual test methods, namely ISO-DIS 4846-2, the technical note by PROBETON NTN-018 and the newly proposed test methods of the standard is done [2-5].