The general method of rapid consolidation of saturated fine grained soils or soft soils is to use the geotextile vertical drains and these are inserted in the ground with their ends protruding at the ground surface and with water being forced out of them under pressure. The geotextile vertical drains(GVDs), usually consisting of plastic fluted or nubbed cores that are surrounded by a nonwoven geotextile filter, have considerable tensile strength. The plastic cores must have the sufficient drainage capacity, the large filtration area and high tenacity etc. Besides this, they also must have the excellent installation property, resistances to acidic or alkaline solutions and salt water under the high or low temperature. The most commercial GVDs cannot be degraded after finishing their drainage functions and this is the serious and important cause of soil and ground pollution. Hence, it is necessary to develop the smart GVDs that could be decomposed after finishing their drainage functions and have the optimum tensile strength during service period. To do this, the biodegradable polymeric materials should be used to manufacture this purposed drainage geosynthetics though the mechanical properties, especially the tensile strength of GVDs are decreased with biodegradable additives. And the geotextiles that are wrapped the plastic core also should have the eco-environmental and high absorbent properties whereas not occurred the serious tensile strength decrease. In this study, starch and unsaturated polyester as the biodegradable additives were blended with HDPE and PP under the optimum composition ratio to improve the eco-environmental properties of the plastic cores. And the high absorbent fibers were blended with PP fibers to manufacture the manufacture the wrapped geotextiles. Tensile, bending and flexural properties, permittivity, degree of degradation of these biodegradable GVDs were evaluated and compared to those commercial GVDs without these additives. From the ex
By: Han-Yong Jeon, Moo-Sung Lee and Chang-Kyu Park
Faculty of Applied Chemistry, Chonnam National Univ.
Submit Date: 6/7/2010 18:00