Investigation of Evaporation and Cracking of Soil Reinforced with Natural and Polypropylene Fibers

In this paper, the evaporation and cracking characteristics of soils reinforced with straw and polypropylene fibers are studied. The changes in moisture content during evaporation are measured by using a high precision platform scale and the development of surface cracks is captured with a digital camera. The results are analyzed by using a GIS (Geographic Information System) software and the crack ratio and fractal dimension of the cracks are calculated. The results show that the final average moisture content after evaporation of the soils with straw and polypropylene fibers is increased by 69.90% and 49.75%, respectively, compared with the soil without fibers. The rate of evaporation can be divided into three stages: Stage I: Initially stable; Stage II: Decreases rapidly, and Stage III: Decreases slowly and tends to be stable. The time of the appearance of the first crack in the soil without fibers is earlier than that in the soils with fiber reinforcements. The final crack ratio of the soils with straw and polypropylene fibers is reduced by 6.79% and 14.16% compared to the soil without fibers. Therefore, adding fiber to soil can reduce water evaporation and inhibit cracking which provides a technique for improving soils in arid areas.