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Representative Testing of Expansive Soil Treatment Technologies for Transportation Earthworks

项目名称：	Representative Testing of Expansive Soil Treatment Technologies for Transportation Earthworks
摘要：	The shrink-swell behavior of expansive soils reduces transportation infrastructure longevity in much of the Mountain Plains region (Colorado, North Dakota, South Dakota, Utah, and Wyoming). Roadways are particularly susceptible to the effects of expansive soils due the combination of low ground pressures and large surface areas. The pervasiveness of expansive soils in the continental U.S. is shown in Fig. 1. Current estimates for the annual cost of damage to transportation infrastructure from expansive soils are not readily available, but were estimated by U.S. Housing and Urban Development (HUD) to be approximately $1.1 billion in 1973 (Jones & Holtz 1973) and $4.3 billion in 1981 (Jones 1981; $12 billion in 2017 dollars adjusting for inflation). Given the prevalence of expansive soils in the Mountain Plains region, economical solutions to mitigate damage to transportation infrastructure is necessary to enhance transportation system longevity throughout the Mountain Plains region. The current Mountain-Plains Consortium (MPC) project MPC-509 is aimed at evaluating expansive soil mitigation for transportation earthworks by polymer amendment. The goal of MPC-509 is to provide un-biased information on the effectiveness of commercially available polymer stabilizers. Testing to date has involved four commercially available polymer treatment technologies applied at different dosage rates to a highly expansive soil. Testing on the highly expansive soil has also been performed with varying dosages of Class-C fly ash, lime, and on untreated soil. Testing to date has included standard soil characterization, and tests of hydraulic conductivity (ASTM D5084), swelling potential (ASTM D4546), expansion index (ASTM D4829), and unconfined compressive strength (ASTM D5102). Results to date have shown that traditional stabilizers (lime and Class-C fly ash) are more effective at reducing swelling potential and expansion index than polymeric amendments. However, traditional stabilizers result in an order-of-magnitude increase in permeability, while polymer amendments result in reductions in permeability. Shrink-swell potential is mechanistically based on the addition of water, and the rate of ingress of water into soil is governed by the soil permeability. Thus, existing standard methods fail to provide a representative comparison of traditional and polymeric stabilizers (due to the ways these treatments modify the soils). An alternative method is needed to accurately compare traditional and polymeric stabilization of expansive soils, as well as other innovative materials proposed for use in treating expansive soils.
状态：	Active
资金：	35870
资助组织：	Office of the Assistant Secretary for Research and Technology
管理组织：	Mountain-Plains Consortium
项目负责人：	Kline, Robin
执行机构：	Colorado State University
主要研究人员：	Bareither, Christopher
开始时间：	20171102
预计完成日期：	20220731
实际结束时间：	0