Case Study of Interstate 269 Corridor through Mississippi Focusing on Chemically Stabilized Pavement Layers

Abstract

The Mississippi corridor of Interstate 269 (I-269) is located in northwest Mississippi and construction of this corridor encompassed approximately 27 miles of new Interstate. This study documents I-269 as a case study of the chemically stabilized soil pavement layers. The evaluation comprises pre-construction activities (material selection, mixture design, pavement design, contract information), construction activities (processes, specifications, as-built quality), and an assessment of three cement stabilized base sections. Detailed assessment included on-site specimen preparation using the plastic mold compaction device (PM Device), core drilling, and subsequent laboratory testing for density, unconfined compressive strength, and elastic modulus. This project was able to document and quantify density variability within current Proctor and nuclear gauge practices to the point where there was noticeable agency and contractor risk. Variability is known to exist in large construction projects, but quantifiable measurements over a large project, as presented in this paper, are more valuable than general expectations for basing future decisions. This paper provides evidence that a construction quality control program where nuclear gauge and Proctor compaction practices are interconnected with mechanical property measurements taken on specimens fabricated with the PM Device is worth considering for implementation. The PM Device fared well for construction, mixture design, and pavement design activities when benchmarked relative to the density, strength, and modulus of the several dozen cores taken and assessed from I-269.

Demonstrating Field Use of the Plastic Mold Device on Full-Depth Reclamation Projects in Mississippi

“…The PM device matching cores is the most compelling assessment in the view of the authors. Past projects have also documented the aforementioned challenges with Proctor and nuclear-gauge-only assessments where variability of reported density was to the point where there was noticeable agency and contractor risk ( 22 ).…”

“…Even with larger sized material, the variability in γ dry was similar to other field projects where the PM device was used with AASHTO M 145 A-2-4 soil. For example, Interstate 269 reported γ dry ranges of 4.9–11.5 pcf depending on sampling location ( 22 ). Highway 84 reported γ dry ranges of 0.4–2.4 pcf depending on sampling location and PM specimen size ( 23 ).…”

“…For example, Interstate 269 reported γ dry ranges of 4.9–11.5 pcf depending on sampling location ( 22 ). Highway 84 reported γ dry ranges of 0.4–2.4 pcf depending on sampling location and PM specimen size ( 23 ). State Route 9 and State Route 475 reported γ dry ranges of 1.7–4.4 pcf and 5.9–7.9 pcf, respectively ( 21 ).…”

“…UCS ranges reported for Groups 1, 2, and 3 were comparable to UCS ranges reported for other MDOT field projects where the PM device was successfully implemented. Average UCS ranges of 261 psi on Interstate 269, 116 psi on U.S. Highway 84, 308 psi on State Route 9, and 257 psi on State Route 475 ( 21 – 23 ). These ranges are comparable to UCS ranges seen in Table 4, indicating the PM device produced similar UCS variability in FDR material as it did with cementitiously stabilized fine-grained soils.…”

Time Delay Effects on Compactability of Soil-Cement Materials during Proctor Testing

“…Over the last 15 years, MDOT has funded several soilcement studies focusing on design, construction, and performance (17)(18)(19)(20)(21)(22)(23)(24). George (17) conducted full-scale field trials to examine reflective cracking and overall field performance of cement treated base pavement layers.…”