Research and Development of one Kind of Acousto-Elastic Sensitive Concrete Material

Abstract

A tentative experiment has been conducted on polymer modified cement concrete now widely used. By filtering through 297 kinds of traces of polymer modified cement concrete samples tentatively mixed, we acquire a proper mix proportion, according to which, a total of 75 groups of 225 polymer modified cement concrete specimens are produced. After further selective preference of these specimens, ultrasonic test is done on the selected ones under different loading conditions. Afterwards, signal processing is accomplished by using wavelet transformation and we preliminarily find a kind of acousto-elastic sensitive concrete material which is comparatively sensitive to stress. This kind of material is produced by mixing epoxy resin, styrene-acrylic emulsion, acrylic emulsion, auxiliaries and iron powder into cement concrete together. The sensitivity of ultrasound and stress of this kind of modified concrete behaves preferably well as follows: at the low stress stage, not only the correlativity curve of ultrasound velocity and stress but also the correlativity curve of weighted spectrum area and stress arises apparently. If this kind of material can be applied to the practical engineering successfully, the acousto-elastic test accuracy of the concrete service stress will be greatly improved.