Utilizing Turf Rubber Infill in HMA

Description

Utilizing Turf Rubber Infill in HMA

DingXin Cheng*, Mario Jaquiz**, and Thai Son Tran*

*California Pavement Preservation Center

Langdon Hall Suite 203

California State University, Chico

Chico, CA 95929

dxcheng@csuchico.edu

ttran24@csuchico.edu

**California Department of Transportation

Office of Safety Innovation & Cooperative Research

Division of Research, Innovation and System Information (DRISI)

Mario.Jaquiz@dot.ca.gov

ABSTRACT.

While extensive research has been conducted on crumb rubber asphalt, there is a lack of studies on the recycling of turf rubber infill (TRI) materials from athletic fields for use in asphalt pavements. This study assesses the potential of utilizing TRI in asphalt mixtures through developed dry and wet processes. The Superpave method was used for mix design, and performance tests such as the Hamburg Wheel Tracking (HWT), Indirect Tensile Asphalt Cracking Test (IDEAL-CT) were conducted to evaluate rutting and cracking resistance in asphalt mixtures, respectively. HWT Results indicated that mixtures with TRI exhibited lower rutting resistance than conventional hot mix asphalt. These TRI-asphalt mixtures didn’t meet Caltrans rutting standard, except for the mixture with 3% TRI (Type AB). Additionally, TRI-asphalt mixtures via the dry process outperformed the wet method in rutting resistance. In the wet process, the binder test demonstrated that the incorporation of TRI into asphalt binder significantly enhances its properties. The improved G*/sin(δ) values suggest a promising enhancement in both durability and deformation resistance at elevated temperatures, making this rubber-modified asphalt well-suited for hot climate areas. The IDEAL-CT showed that the wet method TRI-asphalt mixtures had excellent cracking resistance, exceeding general requirements by about eight times. From the analysis, it is recommended to use TRI asphalt for thin overlays to reduce rutting, enhance cracking resistance, and improve pavement fatigue life. Future research should focus on increasing the rutting resistance of these mixtures to promote their wider use in pavement applications.

KEYWORDS: Turf Rubber Infill (TRI), Crumb Rubber, Superpave Mix Design, Rutting Resistance, Cracking Resistance.