Shota YAMADA

The Examination that Salt Permeation Nature in Prestressed Concrete Member is Experimental

SuperviserFTakumi SHIMOMURA

The water cement ratio of Prestressed Concrete is small, and holds the design which doesn't forgive a crack. The resistance of facing steel material corrosion from being always under the compression stress can be expected.
The permeation distance which ink is used for as the spare experiment, and the amount of permeation were measured, and influence grasping of Prestress was done.
As for the spare experiment, test pieces pickled ink in the dilution solution for 7 days 10 times. It was made dryness condition by drying it before pickle, and a change in weight was measured. The permeation distance of the thing which saw the influence of prestress a little and which was taken didn't become an examination object in the amount of permeation by the permeation character of the ink.
A water cement ratio and the size of prestress were made to change, and an experiment was done as for the salt permeation experiment.
A water cement ratio made 40% 55% of 2 levels, prestress 0% 10% 30% of 3 levels of the compression strength at this time.An environment was made the promotion was exposed the salt water. The decline of the salt permeation distance by prestress was presumed a result in 40% of the. water cement ratios. On the other hand, the difference by prestress in 55% wasn't seen in comparison with 40% of the water cement ratios. It can be said that a rational result could get it from generally chlorination thing ion concentration's being small in the depth direction.
The crack introduction pieces was done in the salt permeation experiment at the same time. The action which closed a crack by prestress was added and made that condition. It cracked, and a result in the crack introduction test pieces showed big value in comparison with test pieces. Even if it is compared with theory value as a crack condition-less, it can be said that the decline of the salt permeation resistance due to the crack can't be ignored from having shown big value.
The improvement of the salt permeation resistance by prestress could be able to be realized in this research. A result is rational, and it can be said that there is a room that an examination is done more fully as a tendency about it.