Measurement of Internal Damage with the SS137244 Test Method

摘要

The Slab-test, a slightly modified version of the Swedish freeze/thaw test method for surface scaling, SS137244, is going to be the European reference test method. In order to further develop the method for simultaneous measurement of internal damage also, a number of tests have been carried out in the Nordic Countries within the framework of NORDTEST. The main emphasis has been put on linear length increase and increase in ultrasonic pulse transmission time (UPTT). Tests carried out at the Cement and Concrete Laboratory, Aalborg Portland, have indicated, that for water-saturated, non air-entrained concrete, with water/cement ratios below 0,5, a linear correlation between length increase caused by internal cracking and increase in ultrasonic pulse transmission time exists. From the results reported in this paper, and parallel tests carried out on four other Nordic laboratories in a NORDTEST-project, it is concluded, that the Slab-test is well suited to determine internal cracking as well as scaling on the same specimens and during the same freeze/thaw test. This project concludes, that UPTT is well suited to detect severe internal damage during repeated wet freeze/thaw test. Thus the Slab-test can be made a very applicable test method for both surface scaling and internal damage.