Effectiveness of ECC in curtailing re-emergence of weeds on an earth embankment surface

Light is a key element for the photosynthesis, growth and re-emergence of weeds on the surface of an earth embankment. The weeds are detrimental to the durability of the embankment. It is therefore necessary to curtail the re-emergence of the weeds by using a suitable repair material. Engineered Cementitious Composites (ECC) is a ductile material which produces fine cracks of less than 0.1 mm width. In this study, the effectiveness of ECC in preventing the penetration of light and thus curtailing the re-emergence of bamboo was investigated. Ordinary mortar was used for comparison. Luminance tests were carried out on 10 mm ECC and mortar plates. Strain variation in ECC and mortar plates cast in situ over bamboo stumps was also measured. It was found that luminance through the ECC and mortar plates with no cracks and the ECC plates with cracks, was less than the minimum photosynthetic photon flux density (PPFD) required by the bamboo to photosynthesize. However, luminance through the mortar plate with a single through crack was more than the required minimum PPFD. In addition, the analysis of the strain variations indicated shooting of the bamboo stumps did not occur under both plates. Therefore, ECC and mortar can effectively curtail the re-emergence of bamboo from the surface of an earth embankment before the production of cracks. After the production of cracks, only ECC is effective.