Lowering Co2 Emission and Making Concrete More Environmentally Friendly by Adding Limestone

EPA Grant Number: SU835707
Title: Lowering Co2 Emission and Making Concrete More Environmentally Friendly by Adding Limestone
Investigators: Abdel-Mohti, Ahmed , Boulanger, Bryan , Barnhart, James
Current Investigators: Abdel-Mohti, Ahmed , Boulanger, Bryan , Barnhart, James , Alves, Rafael , Wolf, Addison , Lupinacci, Julia , McDaniel, Allan , Weingart, Meredith , Ballmer, Boston , Lin, Zexing , Filho, Luciano
Institution: Ohio Northern University
EPA Project Officer: Hahn, Intaek
Phase: I
Project Period: August 15, 2014 through August 14, 2015
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2014) RFA Text |  Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Chemical Safety , P3 Awards , Sustainable and Healthy Communities

Description:

The goal of our proposal, “Lowering CO2 Emission and Making Concrete More Environmentally Friendly by Adding Limestone”, is to produce a more sustainable concrete by engaging a team of undergraduate civil engineering students to address challenges associated with incorporating limestone in the concrete mixture and measuring the amount of CO2 emission.

Objective:

The primary objective of this proposal is to test materials performance and carbonation capacity of Portland limestone concrete (PLC) mixtures. A successfully developed product will meet the existing technical specifications for material performance while demonstrating higher carbonation capacity (the ability of the concrete to sequester carbon dioxide). U.S. standards currently authorize the use of up to 5% limestone, but incorporating higher levels of limestone (potentially up to 35% limestone) will improve the environmental benefit. Limestone incorporation lowers the embodied CO2 within the production process, while increasing carbonation within the matrix. By one estimate replacing 25 to 35% of cement with limestone in the concrete mixture decreases thermal energy demand by 0.22 to 0.60 GJ/t-cement and reduces direct and indirect CO2 emission up to 140 t CO2/t-cement. However, the material performance at higher levels of limestone remains under-characterized.

Approach:

Working within a team of students, an industry partner, and faculty with expertise in environmental analysis and structural concrete, team members will be involved in research designed to innovate, create, and evaluate a more sustainable concrete product. Team members will create concrete products that incorporate varying percentages of limestone. These sample products will be evaluated to determine whether or not a developed Portland Limestone Concrete meets existing criteria for concrete material design and has less impact on the environment by measuring carbonation.

Expected Results:

The experimental results of this project will inform decision-making concerning the performance of PLC. Specifically, the project’s expected results will determine the effect of adding more than 5% limestone on the performance of fresh and hardened concrete. Also, the impact of the produced concrete on the environment will be evaluated and compared to that of the conventional concrete through carbonation depth testing in a seal chamber environment. Phase I research will focus on evaluating the performance against the existing technical specifications and measuring carbonation depth against Portland cement concrete. In phase II, the optimal percentages of limestone incorporation will be tested. In addition, the durability of PLC samples will be evaluated and the embodied CO2 of PLC will be determined through life cycle analysis.

Supplemental Keywords:

concrete, pavement, CO2 emission, sustainability, limestone

Progress and Final Reports:

  • Final Report