Evaluation of the Anti-Erosion Characteristics of an MICP Coating on the Surface of Tabia

Abstract

Most tabia sites exhibit accelerated decay rates caused by weathering. Weathering damage generally proceeds from the surface to the interior; thus, protecting the surface of tabia sites is an effective method to resist weathering. In this study, the microbially induced carbonate precipitation (MICP) technique is used to form an anti-erosion layer on the surface of tabia. Next, the applicability of MICP for tabia surface erosion control is examined in the laboratory via the static contact angle test, capillary water absorption test, Karsten tube test, durability test, acid resistance test, water vapor permeability (WVP) test, and color change test. Moreover, the effect of the concentration of bacteria and cementation reagent on the surface erosion control is analyzed. The test results show that MICP can significantly improve the water resistance of a soil sample by changing the microstructure of the surface. Higher concentrations of bacteria and cementation reagent allow the sediment layer to provide better protection; however, this effect is not linear. The concentration threshold reduces the positive effect of the bacterial concentration on the water resistance of the soil surface. The MICP protection layer offers favorable durability with little negative impact on the air permeability and color of the sample. The use of an MICP protection layer can effectively relieve the surface erosion of earthen sites.