Abstract: The adhesion of Limnoperna fortunei to the inner concrete walls of a water transmission building causes the deterioration of concrete performance. Its adhesion law and erosion mechanism is of great value for the prevention and control of it. This study examines the behaviors of L. fortunei inside a water transmission building, focusing on its adhesion law, foot invasion mechanism, and spatial differences in length, and analyzes its influence on the physical properties of concrete through hardness tests and erosion depth tests on concrete in-situ. We reveal the micro mechanism of concrete erosion by L. fortunei based on a comparison of the micro morphologies, chemical element changes, and XRD diffraction patterns of the concrete before and after erosion; A phase transformation mechanism of the eroded concrete is suggested. The results show the attachment density of L. fortunei exhibits a decay trend from the inlet to outlet inside an aqueduct. Its attachment density inside an inverted siphon fluctuates along the way, but is generally stable; A positive correlation is observed between its vertical separation force and body length, and the latter features long in the south and short in the north in a large scale space, with a difference of 10mm. Under its long-term adhesion, a concrete surface suffers a decrease in material hardness and an increase in erosion depth; the micro morphology is loose and porous. Erosion causes a loss of Ca and Fe elements and creates silica, a major product of concrete.

Key words: Limnoperna fortunei, adhesion law, erosion depth, element change, phase change