Feasability of Using Recycled Waste Plastic in Concrete Pavements in Nebraska

Authors

Amasi Hajahja, University of Nebraska-LincolnFollow

First Advisor

George Morcous

Second Advisor

Jamilla E. Sudo Lutif Teixeira

Date of this Version

7-2025

Document Type

Thesis

Citation

A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Construction Engineering and Management

Under the supervision of Professors George Morcous and Jamilla E. Sudo Lutif Teixeira

Lincoln, Nebraska, July 2025

Comments

Copyright 2025, Amasi Hajahja. Used by permission

Abstract

Waste plastic (WP) is a growing environmental concern due to its non-biodegradable nature, large-scale production, and harmful impact on natural resources. With nearly 75% of WP in the United States ending up in landfills, effective recycling strategies are urgently needed. In parallel, the limited availability of natural aggregates highlights the need for alternative materials in concrete construction. This study investigates the feasibility of using recycled waste plastic (RWP) in concrete mixtures, both as aggregates and fibers for rigid pavement applications in Nebraska. Concrete mixtures were prepared by partially replacing natural fine aggregates with recycled plastic aggregates (RPA) at replacement levels of 5%, 10%, and 15% by volume of the natural fine aggregates. Additionally, recycled plastic fibers (RPF) were incorporated into the mixtures at dosages of 0.5%, 1%, and 1.5% by total volume of the concrete. RWP materials underwent characterization tests to compare with traditional materials. A preliminary investigation evaluated fresh properties and compressive strength to assess suitability based on Nebraska Department of Transportation standards (NDOT), using the standard (47B) pavement mixture as a control. Mixtures meeting performance criteria were selected for further testing, including splitting tensile strength, flexural strength, and modulus of elasticity. Fracture behavior was assessed through semi-circular bending (SCB) tests. Also, durability was evaluated using the surface resistivity test, which assesses electrical resistivity as an indication of chloride ion penetration. Results showed that the inclusion of RWP aggregates can increase workability. Statistical analysis indicates that up to 10% RPA replacement does not significantly reduce compressive strength while satisfying the standard requirements set by the NDOT for paving applications. When RWP was used as fiber, a reduction in workability was observed. Nevertheless, the addition of RWP fibers had a positive influence on the flexural strength, ductility, and cracking resistance, with an optimum content of 1.5%. Surface resistivity confirmed acceptable durability performance with respect to NDOT requirements. Overall, incorporating RWP into concrete as aggregate or fibers offers a sustainable solution by reducing WP in landfills while maintaining or improving concrete performance for pavement applications.

Advisors: George Morcous and Jamilla E. Sudo Lutif Teixeira