Development of Test Method for Evaluating Root Resistance Using Simulated Root focus on the Enlargement Growth of Root

Damages such as rising and cracking due to enlargement growth of roots are quite often observed in the components such as path pavements, curbs, retaining walls and garden furniture on green roof. To avoid the defects, root resistance of those components used for green roof should be estimated by a suitable test before actual applications of them. In this study a test apparatus and a test method to evaluate root resistance caused by enlargement growth of root were developed. First, the simulated root for similarly reproducing the enlargement growth was developed on the basis of the actual behavior of the root of a cherry tree. It consists of two half cylinders of aluminum and a hydraulic jack inserted between them, and the whole simulated root covered with EVA sheet to give the similar mechanical property of the root.

Then, the root resistance test was carried out using the simulated root for an asphaltic pavement as an example. It was observed that the test result of nature of asphaltic pavement damage was similar to that observed on actual asphaltic pavements. It was found that the simulated root was useful for evaluating root resistance.