The Research Of Self-healing Concrete With PVA Fibers

Concrete self-healing technology is an imitation of the mechanism of animal bone tissue regeneration and recovery after trauma. When the cracks or damages occur in the concrete, applying the method of compounding the repair adhesives with concrete, the damages of concrete are able to self-heal, regenerate and even improve the material performance.This paper is an analysis of a test of a self-healing crack sample--the cracking resistance of PVA fiber concrete. The restoration agent used in this article is determined as: modified water-glass and polyurethane, hollow glass tube as the storage containers.By the bending test, it can be verified how the embedded hollow glass tube affects the bending resistance of the PVA fiber reinforced concrete. Two bending tests were performed to compare the results of the concrete crack recovering by using different numbers of glass tubes. Several conclusions could be obtained by the testing results:①Both the concrete plastic shrinkage tests and splitting tensile tests were carried out by using different samples with different PVA fiber contents to verify which PVA fiber content is preferable for the inhibition of the plastic cracking and for the increasing of splitting tensile strength. The final test results showed that the concrete with 0.6% PVA fiber content is the optimal sample.②The bending tests were performed by using different number of hollow glass tubes in order to know how the number of hollow glass tubes affecting the bending strength of PVA fiber reinforced concrete. The strength of PVA fiber concrete increased by using the samples with different numbers of built-in hollow glass tubes.③Two bending strength tests were performed to evaluate the repairing effect by using the samples with different number of built-in hollow glass tube and with different kind of repair agent. Those results were obtained from the test analysis:1) Based on first bending strength test, it can be concluded that with 5 tubes performs better than with 3 tubes.2) As repair agent, the polyurethane has slightly higher bending strength effect than that with water-glass.3) With the increased times of concrete repairing, the response rate of fixed bending strength will become less powerful.④The number of internal tube and the type of repair agent are important factors for the self-healing effect of concrete cracking.