Title: Engineering Properties of Concrete with Extruded Waste Recycled Plastic Aggregate as a Partial Coarse Aggregate Replacement

Author(s): Kimberly Waggle Kramer, Lauren Costello, Katie Loughmiller, and Christopher Jones

Publication: Symposium Paper

Volume: 361

Issue:

Appears on pages(s): 43-58

Keywords: Recycled-plastic aggregates, Compressive strength, Tensile strength, Flexural strength, Sustainability

DOI: 10.14359/51740606

Date: 3/1/2024

Abstract:
This research studies the use of a fractional coarse aggregate replacement product (PA). PA is a unique blend comprised of recycled plastics, glass, and minerals; all collected from the waste stream. The use of PA and other similar products may contribute to reducing plastic waste in the waste stream. To test the feasibility of PA as a partial, natural aggregate replacement, four different mixtures of concrete were batched and tested. The concrete mixtures were based on the standard commercial interior normal-weight concrete mixture. This is a non-air-entrained mixture, provided by a local concrete batching plant (MCM), with a design strength of 4000 psi (27.6 MPa). The four concrete mixtures tested were a control mixture with no variations to the original mixture design as well as three mixtures with 15%, 30%, and 45% coarse aggregate replacement by volume. The compression strength, tensile splitting strength, modulus of rupture, and density of the concrete are examined. The focus of the paper is the concrete compressive strength because it is the primary determining factor in concrete design. Fresh concrete properties and hardened concrete properties were examined and recorded. Slight changes to the overall fresh concrete properties of workability, density, and slump were recorded. The hardened concrete properties include compression, tensile splitting, and modulus of rupture. The results of the compression tests show a strength proportionally decreased with the percent increase in PA replacement – 15% replacement with an 18.1% decrease, 30% replacement with a 35.6% decrease, and a 45% replacement indicated a 45.3% decrease at the 28-day test. The results of the tensile splitting tests and modulus of rupture tests both indicate similar results of a decrease in strength as the replacement rate of PA increased.