Experimental studies on sacrificial layer in conservation of earthen sites

According to the characteristics of earthen sites' erosion and the existing environments of arid and semiarid zones, this work comes up with the conception of sacrificial layer. Covering the surface of the earthen site with a mud coating layer, similar to the natural materials found at the site, it would provide a protective layer for exogenic forces to destroy, while preserving the earthen site. Experiments were carried out to separately test the shrinkage rate, heat sensitivity, color difference, mechanical properties, vapor permeability, wetting-drying cycle, and rainfall erosion by adding wheat chaff and hemp fibers with different proportions. Experimental results show that wheat chaff and hemp fibers are ideal modified materials for the sacrificial layer with good performance. The optimum proportion of hemp fiber, wheat chaff, and soil was 0.5:1.25:100. The sacrificial layer has broad application prospects to the surfaces of earthen sites in arid and semi-arid zones. (C) 2019 Elsevier Masson SAS. All rights reserved.