Application of Mechanistic-Empirical Pavement Design Approach into RCC Pavement Thickness Design
Semester of Graduation
Master of Civil Engineering (MCE)
Department of Civil and Environmental Engineering
Roller compacted concrete (RCC) has been gradually getting the preference for many pavement applications as a cost-effective, rapid, and durable construction material. Prior studies on RCC pavement already established that a thin RCC pavement can provide adequate structural performance if constructed cautiously. Nevertheless, many of the existing studies emphasized that fatigue behavior of RCC should be examined thoroughly since the most common failure mechanism of RCC pavement resulted from fatigue cracking. Over the years, researchers have made careful investigations to explain the fatigue behavior of RCC pavement when compared to conventional concrete pavement. However, a considerable part of these studies investigated the fatigue behavior mostly based on laboratory compacted beam or slab specimens and was quite incapable to consider the variability due to field construction procedure. Additionally, still, now pavement designers use either AASHTO 1993 empirical procedure or existing rigid pavement ME design protocols and thermal properties to implement RCC pavement application as there is no fully developed mechanistic-empirical (M-E) pavement thickness design procedure established for RCC pavement.
In this study, a comprehensive beam fatigue test experiment was performed using field saw-cut RCC beam samples from accelerated pavement testing (APT) sections in the Pavement Research Facility (PRF) of Louisiana Transportation Research Center (LTRC) to investigate the fatigue behavior of in situ RCC pavements. In total 68 beams were prepared and tested from the field that marked this work as the first research study to explore the fatigue behavior of field RCC beam specimens prepared/constructed with a high-density asphalt paver and a vibratory roller. The results indicated that a well-compacted RCC pavement can achieve higher flexural strength and exhibit better fatigue life than conventional concrete pavement. This study also observed a strong linear positive correlation (R2= 82%) between the static flexural strength and laboratory-measured density of field specimen while inspecting the field pavement structure and compaction variability. Based on the beam fatigue test results, a RCC fatigue-life (S-N) prediction model was developed, and a reliability component was incorporated to provide a more reliable solution for designing RCC pavement thickness. Fatigue strength, that is defined as the unlimited fatigue life of RCC beams, was observed to be 65% of the static flexural strength. Simultaneously, in-situ strain responses and thermal properties (ie. coefficient of thermal expansion, temperature profile along with the slab depth) necessary for pavement design were also explored resulting from Accelerated Pavement Testing (APT). All the findings of this study, including the developed fatigue model were based on the specific type of RCC mix design used in the APT sections. Lastly, a mechanistic-empirical RCC pavement thickness design framework was proposed based on the findings of this study and currently available rigid pavement M-E design protocols. Based on the proposed design procedure a step-by-step design example was also presented in this study. This thickness design procedure can be helpful to determine an accurate RCC thickness for medium-low volume roadways.
Sobhani, Md Golam, "Application of Mechanistic-Empirical Pavement Design Approach into RCC Pavement Thickness Design" (2022). LSU Master's Theses. 5485.
Available for download on Friday, January 12, 2029