TEMPERATURE DISTRIBUTION IN CONCRETE DURING FREEZE-THAW TEST

Description

Concrete deterioration by frost action is a major durability issue in cold climates. Different theories have been put forward to explain the damage mechanism. However, the basic phenomena behind the frost damage are still not fully understood. The temperature gradient along the depth of concrete during frost action is often neglected in the research. It is one of the objectives of a recently started PhD project to investigate the importance of the temperature gradient. It is difficult to get a good resolution in the temperature measurements with conventional thermocouples cast in the concrete. Therefore, the temperature distribution along the depth of concrete need to be monitored with some innovative experimental technique. Here, a special optical fibre, prepared to measure the temperature at certain depths from the reflection of light, is being used for temperature monitoring. The temperature is monitored with conventional thermocouples in the test liquid (top of the specimen) and at the bottom. At 5 points located at certain depths from the test surface, the temperature profile is monitored by the optical fibre. A mini-freezer is used to apply freeze-thaw cycles, see Fig. 1. The mini-freezer is placed inside a climate chamber to control the surrounding temperature during the freeze-thaw test. The temperature measurements are shown in Fig. 2. The results of such a study have the potential to correlate the frost damage with the temperature distribution in concrete and temperatures of the surrounding atmosphere. In addition, the presentation of an innovative experimental technique for temperature measurement in the freeze-thaw test shall be a positive outcome.

Period	28 Aug 2019
Event title	73rd RILEM Annual Week & International Conference on Innovative materials for Sustainable Civil Engineering (IMSCE)
Event type	Conference
Conference number	73
Location	Nanjing , ChinaShow on map
Degree of Recognition	International