CDF Test - Test method for the freeze-thaw resistance of concrete - tests with sodium chloride solution (CDF)

FOREWORD During RILEM TC 117-FDC meetings, the drafts of the three procedures recommended by TC 117 and published in Materials and Structures (Vol. 28, No. 177) were discussed extensively. As already stated in the draft edition, TC 117-FDC will not issue a final recommendation concerning any procedure for which the precision following ISO 5725 is not given. Before the meeting in Sapporo (July 31-August 1, 1995), precision data were published only for the CDF test; this situation has not changed since then. Therefore, RILEM TC 117-FDC unanimously passed the following text proposed by Prof. Janssen: "TC 117 directs RILEM to recommend the CDF test for the determination of the scaling resistance of concrete. However, the committee cannot decide whether the draft procedures for the CF, Slab or Cube tests should be recommended until the precision data for these tests have been made available and the committee has had an opportunity to examine these data." A RILEM recommendation should be restricted to the description and evaluation of the test procedure itself. The regulations should have a substantial scientific basis. Since an acceptance criterion can be modified by reasons which are valid only under certain conditions and economic considerations, a RILEM recommendation could contain at most guideline values. Due to these considerations, the drafts for the CDF test had to be modified (without CF test). However, the necessary modifications were not so important that they required approval by the complete committee. Therefore, TC 117 established an editorial group responsible for these modifications, which consisted of Prof. Fagerlund, Prof. Janssen and Prof. Setzer, the Chairman of the Committee. This work of the editorial group has now been completed. As Chairman of RILEM Technical Committee TC 117-FDC, it is an honour for me to thank all the members, and especially the editorial committee, for their very serious and engaged work, which led to a recommendation having sufficient precision for the freeze-thaw and deicing salt resistance of concrete.