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The slopes along the Friant-Kern Canal were last treated in the 1970s with 4% quick lime to mitigate issues related to slope failure caused by expansive Porterville soils. The immediate benefits of lime treatment were well documented by the Bureau of Reclamation. However, questions remain over the long-term durability of lime-treated materials. In this study, we compare the engineering properties and changes in the soil mineralogy of treated and untreated sections to establish the effectiveness of lime after more than 40 years of performance. A geochemical model was developed using the GEM-Selektor program to simulate the geochemical reactions in the soil-lime system and predict stable pozzolanic products. The experimental results show a reduction in the plasticity index from 23 to 6 after lime treatment together with a tenfold increase in strength. Lime addition lowers the risk of volumetric expansion and erosion in soils from moderately high to very low. Further, a pH increase from 6.30 to 8.90 in lime-treated sections indicates that lime treatment continues to be effective. X-ray fluorescence analysis shows the presence of Ca2+ ions in quantities similar to the initial treatment dosage indicating negligible leaching of lime. The geochemical model provides evidence of the formation of pozzolanic products in the soil-lime system which was validated using thermogravimetry analysis. The performance history of the Friant-Kern Canal together with the findings of this study affirm the long-term durability of lime treatment on this project and strengthens the case for using lime in the repair of hydraulic structures.

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In the face of increased demand and exposure to environmental effects, the condition of road pavements continues to decline while resources for their preservation remain limited. Thus, the task of managing pavements has to be done systematically and objectively. This paper outlines the steps involved in developing a multi-year pavement Maintenance and Rehabilitation (M&R) plan. These include: (1) condition assessment; (2) network inventory and database development;(3) identification of pavement sections requiring M&R; (3) needs analysis; and (4) impact analysis. As a case study, the project was performed on the road network inside the Texas A&M University campus that consists of 13.95 miles of roadway, 80% and 20% of which are concrete and HMA pavements respectively. Condition assessment was done according to ASTM D 6433-07 and using the Pavement Condition Index (PCI) as indicator of pavement performance. Data collected were then entered into a database which also contains information on traffic and roadway characteristics. PCI threshold values were established to identify sections that are in need of M&R and the most costeffective treatment based on long-term performance benefit and life-cycle cost was proposed for each project. Candidate projects were then prioritized by ranking based on benefit-cost analysis. The needs estimate provides meaningful information on the total amount of budget required to correct all deficiencies in the network. Finally, the impact analysis is used to determine the impact of a reduced budget on network condition as well as the amount of backlog that needs to be addressed.