During these two sessions, concrete stakeholders (including but not limited to materials producers, concrete manufacturers, structural engineers, governments, and contractors) will be educated and informed about the EPDs and LCA methods for performing environmental impact assessments and disclosing their potential environmental impacts. Basic content and progress toward developing assessment tools and guidelines will be demonstrated. Speakers will provide their insight and experience about the challenges and opportunities for using available sustainability tools concerning the performance and design criteria. Participants will also be informed about the role played by different concrete stakeholders in the evaluation and implementation of environmental impact metrics.
Learning Objectives:
(1) Identify the limitations of bio-based solutions and the degree to which cement-based products can contribute to the decarbonization of the construction industry;
(2) Discuss the role of life cycle assessment (LCA) in reducing the GHG emissions from lightweight aggregate concrete products;
(3) Explain how performance improvements and mix design paradigms can reduce the GHG emissions of cement-based products;
(4) Identify pathways for validating and contributing to carbon dioxide removal by means of concrete.
This session has been approved by AIA and ICC for 2 PDHs (0.2 CEUs). Please note: You must attend the live session for the entire duration to receive credit. On-demand sessions do not qualify for PDH/CEU credit.
Comparing the CO2 Reduction Potential from Cement and Concrete Optimization to that Possible from Bio-Based Materials in the Context of Global Housing Needs
Presented By: Karen Scrivener
Affiliation: Ecole Polytechnique Federale De Lausanne
Description: Bio based materials like timber and bamboo are much touted as solutions to the reduce the CO2 emissions from construction, but even a simple analysis shows that the potential to increase the use of such materials is very limited. In contrast, cement-based materials (concrete and mortar) make up more than two thirds of building materials. If their use is better optimized, much larger CO2 savings are possible. In this presentation we will look at the relative savings possible through these two routes (bio-based vs good use of cement) in the context of the demand for housing worldwide until 2050. In the cement-based scenario most of the possible savings can come from the use of the use of limestone calcined clay cement (LC3) and minimizing the amount of cement in concrete.
Sustainability of Lightweight Aggregate Concrete Using Environmental Product Declarations
Presented By: Fariborz Tehrani
Affiliation: Expanded Shale, Clay and Slate Institute
Description: Decision-making in engineering practices requires an objective approach to sustainability and resilience. Lifecycle assessment (LCA) of resources and footprints is essential for quantifying project performance measures concerning sustainability, including cost, energy, emissions, waste, and water consumption. Environmental product declarations (EPD) manifest these measures using detailed bottom-up estimates of various processes of infrastructure materials throughout their lifecycle. This presentation highlights challenges and opportunities in developing LCA and EPD of rotary-kiln-manufactured lightweight aggregates, including expanded shale, clay, and slate (ESCS) in concrete applications. Existing literature has established links between the ESCS characteristics and lightweight aggregate concrete performance related to safety, durability, insulation, and other objectives. Application of ESCS in concrete materials typically involves the production of low-density, high-performance, and internally cured concrete. Employed analyses in this work utilize data from mining to process technology of ESCS and best practices from construction to decommissioning and reuse of concrete systems, resulting in cradle-to-grave and beyond cycles. The outcomes of this study include measurable objectives of lightweight aggregate concrete products as vital parameters for planning, design, and construction in infrastructure development. Discussions focus on the feasibility and practicality of the objective procedures concerning available data and methods. Conclusions emphasize the significance of LCA in a realistic assessment of lightweight aggregate concrete benefits regarding safety and service performance parameters, such as strength and durability, and their contributions to sustainable and resilient infrastructure development.
Optimizing Concrete Mixture Proportions by Coupling Thermodynamics, Physics-Based Models, and Life Cycle Assessment
Presented By: Jason Weiss
Affiliation: Oregon State University
Description: Current mixture proportioning procedures have primarily been based on empirical relationships based on engineering concepts and experience. This presentation discusses the use of thermodynamics and physics-based models. These models enable the physical and chemical properties of the available materials to be assembled to meet the constraints associated with the project. The chemical composition, cost, and carbon footprint of the materials used with be evaluated along with service life prediction. Life cycle assessment will also be discussed.
Practical Methods to Reduce the Embodied Carbon with Concrete Mixture Design
Presented By: Tyler Ley
Affiliation: Oklahoma State University
Description: Concrete mixtures require a certain workability to be able to be placed and consolidated. When this workability is not obtained then the mixture design must be modified by adding more water or cementitious content. This presentation will give an overview of a new mixture design process that takes into account the gradation of the aggregate and how it impacts the workability of the concrete. This presentation will specifically show how the fine sand content (sum of the material retained on the #30, #50, #100, and #200) impacts the volume of cementitious material in the mixture to achieve a certain workability of the concrete. Some practical mixture design example will be shown and the resulting impact on the embodied carbon will be quantified.
NEU Validation/Verification Program Overview and the Corresponding Role of LCAs and EPDs
Presented By: Dean Frank
Affiliation: NEU - An ACI Center of Excellence For Carbon Neutr
Description: This session will provide an overview of the NEU Validation/Verification Program, which was recently launched by NEU: An ACI Center of Excellence for Carbon Neutral Concrete. Based on internationally accepted standards, the program provides an impartial assessment of GHG-related environmental claims made by manufacturers of materials and technologies related to reduced-carbon concrete construction. The assessment requires a review of qualified/independent test data, which includes LCA and/or EPD results.