Grantee Research Project Results

Plient Recycled Steel Fiber Reinforcement to Achieve Ultra-Low Carbon Concrete Buildings

EPA Contract Number: 68HERC25C0025
Title: Plient Recycled Steel Fiber Reinforcement to Achieve Ultra-Low Carbon Concrete Buildings
Investigators: Donnelly, Charles
Small Business: Circle Concrete Tech, Inc.
EPA Contact: Richards, April
Phase: I
Project Period: December 16, 2024 through June 15, 2025
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2025) RFA Text |  Recipients Lists
Research Category: Small Business Innovation Research (SBIR)

Description:

Substantial R&D is focused on the carbon footprint of concrete but almost exclusively targets reducing or replacing the Portland cement component. Concrete is typically reinforced with steel bars (rebar), wire mesh, or manufactured steel fibers, and the carbon footprint of the reinforcement can approach or even exceed that of the cement. Our innovation is Plient, an engineered recycled steel fiber product that replaces rebar, mesh, or manufactured steel fibers as concrete reinforcement. Plient fibers, which use recycled steel as feedstock, have a carbon footprint from 7x - 19x lower than rebar, mesh, and manufactured steel fibers.

Plient was developed through 5+ years of research at Texas A&M University and is being exclusively licensed to Circle Concrete Tech, Inc., founded in part by the research team at Texas A&M. A thorough market analysis indicates that Circle can sell Plient fibers for about ½ the price of rebar and at least 3x lower than manufactured steel fibers. The target market is industrial concrete floors for facilities like datacenters and warehouses, with an annual serviceable obtainable market (SOM) of over $200M in gross sales of Plient fibers that is limited only by the (ever increasing) number of tires recycled each year. Lab tests, customer discovery, and initial pilots indicate Plient is commercially viable with an enthusiastic customer (building construction contractors) base.

Tests demonstrate sufficient residual flexural strength – the key design variable for fiber reinforced concrete floors – is obtainable for Plient fibers to achieve equivalent post-crack strength to that provided by rebar, indicating technical viability. However, our prototypes to date have been small, used low fiber content, and were executed without pumping. Potential customers have questioned whether Plient is pumpable and whether standard placement, finishing methods, and equipment may be used at the high fiber doses needed to achieve sufficient strength. This SBIR project will test these questions, with the anticipated outcome that Plient reinforced concrete will prove pumpable and finishable with standard tools, methods, and equipment so that a significant technical roadblock to commercialization is eliminated. Once commercialized, Plient will have a tremendous impact on carbon footprint and reduce landfill waste through higher recycling rates of the feedstock materials driven by the new demand created by Plient. Ultimately, Plient has the potential to reduce the carbon footprint of reinforced concrete by more than 2.5M tons annually and save more than $3B in construction costs annually.

Progress and Final Reports:

Final Report