摘要: The demand for pavement networks in the United States is greater than ever, and the conditions of existing roadways are worsening due to heavier vehicles and increased volume. According to the recent report by AASHTO/TRIP, only ha... 展开 The demand for pavement networks in the United States is greater than ever, and the conditions of existing roadways are worsening due to heavier vehicles and increased volume. According to the recent report by AASHTO/TRIP, only half of the nation's major roads are in good condition (AASHTO, 2009). This report found that major urban centers have the roughest roads--some with more than 60% of roads in poor condition. Weak subgrade soils are a leading factor in this regard. In the last few decades, pavement engineers have been challenged to build, repair and maintain pavement systems with enhanced longevity and reduced costs. Specifically, efforts have been made to improve the design methodology (AASHTO, 2004) and to establish techniques for modification of highway pavement materials. Cementitious stabilization is one of these techniques; it enhances the engineering properties of subgrade soils, which is essential for structurally sound pavements. Although cementitious stabilization is widely used in the United States including Oklahoma to improve subgrade soil properties, the effect of freeze-thaw (F-T) and wet-dry (W-D) conditions, referred to as durability (or long-term performance), is not frequently addressed. Also, detrimental effects of climatic conditions (F-T and W-D) on our national pavement infrastructure have been highlighted by AASHTO and recent NCHRP reports (Little and Nair, 2009; AASHTO/TRIP, 2009). Knowledge about the long-term performance of cementitiously stabilized subgrade soils is expected to be helpful in the development of rational design procedures for better pavements in Oklahoma. 收起