DETECTING METHOD FOR QUALITY DETERIORATION OF CONCRETE BY FREEZING AND THAWING

摘要

PURPOSE:To detect quality deterioration of a concrete in a brief period of time with a small-scale testing device by using a thin piece of concrete exposing an aggregate as a test piece. CONSTITUTION:A test concrete piece T having a size 10X10X40cm in length, width and depth which is generally used as a sample for freezing and thawing tests, is cut to the thickness of 1-2cm on one side. Thus said test piece can be served as one for detecting a progress of quality deterioration inside a concrete through observation, etc. At the same time, because of its thin piece form, it can be judged quickly whether said piece can be durable against freezing damage. With this test piece used, fresh water freezing/thawing tests are conducted and as a result, a quality deterioration which has started on a contact surface between aggregate and mortar inside a concrete is observed at 30 cycles. Submerged tests in the sea water reveal that the test piece has been seriously degraded. In addition, a concrete collapses to pieces at the increased number of cycles for freezihg and thawing and thus is can be used as a test sample for acceleration tests.