Pub. 2 2019-2020 Issue 3

26 With the option of nighttime construction, and without the lengthy curing time typical of concrete (Poole, 2005), asphalt pavements offer the flexibility needed to handle all levels of traffic and can be constructed or maintained quickly with minimal disruption to travelers. In fact, new or newly rehabilitated asphalt pavement can be opened to traffic as soon as it has been compacted and cooled. There is no question of waiting for days or weeks, with traffic being detoured or squeezed. Simply put, the fastest choice in pavement construction is asphalt. The interchange of I-10, I-12, and I-59 east in Slidell, Louisiana, northeast of New Orleans and constructed in 2016, presents a very compelling case for asphalt’s speed of construction when rehabilitating a roadway. Each of these interstate roadways is a critical storm evacuation route that must be opened within 48 hours of a tropical storm entering the Gulf of Mexico during hurricane season. Speed of construction was of the utmost importance for this project due to lateral confinement prohibiting the placement of barricades in the work zone. The mainline roadways of all three interstate highways and six ramps were impacted by this project and the Louisiana Department of Transportation and Development’s (LADOTD) primary traffic control concern was to avoid lane closures during peak travel hours. A list of lane closure restrictions required contractors to complete work on time. Including restrictions on weekdays and weekends when no lane closures are allowed for certain segments, and others in which single lane closures are allowed. Concurrent lane closures on adjacent sections are allowed only in instances where traffic control dictates the prevention of hazardous yield conditions. Both a concrete and an asphalt pavement section were designed by LADOTD. The alternative structural designs for the pavement are shown in Figure 1. Both of the LADOTD alternatives were remove and replace options. Figure 1. Design Alternatives for Louisiana Interchange (Lambert & Savoie, 2012). *Base may be either unstabilized granular, cement stabilized, or asphalt stabilized Existing Subbase Existing Subbase Asphalt Option Concrete Option 2 in. Surface 0.75 in. OGFC 10 in. Binder 10 in. PCC 5 in. Base* Asphalt Value Proposition: Speed of Construction Quantifying Construction Costs