MIT Concrete Sustainability Hub
Carbon Neutrality

Carbon Neutrality

Carbon Neutrality

Carbon neutral concrete is possible. Solutions are available today, and new ones are being developed for the future.

One of the major goals of MIT CSHub is to help realize a carbon neutral concrete industry.

Our analysis of the life cycle of concrete, from creation through demolition, has revealed that it has great implications for climate change. In fact, if the use phase of concrete is considered, concrete can lower the total greenhouse gas emissions of pavements and buildings. CSHub is creating a novel estimate of the total impact of cement and concrete, including direct and avoided emissions. Similarly, CSHub is engaged in estimating and enhancing carbon uptake in concrete.

The U.S. pavement network can absorb 5.8 million tons of CO2 (around 5.5% of emitted CO2 from the cement used in pavements) over the next 30 years. The carbon uptake proportion of the use and end-of-life phase are in the same order. End of life abatement could be more cost-effective than carbon capture, use, and sequestration, with median costs ranging from $25–100/ton CO2 in the United States.


CSHub Research Brief: “Life Cycle Carbon Uptake of the United States Pavement Network”

Ongoing Projects

Understanding the impact of concrete requires estimating not only emissions from production nor even just from the use of the systems it forms, but also the emissions from the systems if they were to have been created some other way. Quantifying improvement within the industry requires not only assessing current levels of emissions but also defining a benchmark against which that is compared. In this project, a comprehensive, auditable system to estimate the total impact of the concrete industry and how that improves over time will be created. This includes not only the emissions associated with the production and distribution of concrete (including its constituent materials) but also the net effect of its use within the buildings and infrastructure into which concrete is fashioned and the impact of its handling during end-of-life. The outcomes of this project provide a comprehensive platform for measuring and reporting the industry climate change goals and reduction targets.

This project focuses on the target of carbon-neutral concrete products in buildings and pavements. A deep exploration of concrete element designs, constituent materials and technologies available, and practical and innovative solutions for the use, maintenance and repair, and end-of-life embodied reduction will be investigated. A key element of this project will be exploring the superposed impact that these solutions have on the performance requirements including early strength, late strength, and durability. These already-calculated pathways and publications will help to illuminate the ways in which concrete can be a key contributor to lowering the embodied environmental impacts and meeting greenhouse gas (GHG) reduction targets.

In this project, a precise estimation of carbon uptake for cementitious products, such as masonry blocks, mortars, and structural and non-structural precast and cast-in-place elements used in building and infrastructure systems will be investigated. The historical and projected carbon uptake of the US cement consumption will be quantified using a bottom-up material flow analysis of cementitious products. From an experimental perspective, CSHub research focuses on improving the carbon dioxide utilization in cementitious products. The project outcomes will be used to create guidance on the uptake potentials across a range of contexts (climate, geometry and exposure condition, duration of exposure, concrete mixture, and end-of-life treatment). Ultimately, the surrogate models from this research project will be used to estimate overall carbon uptake in the industry reports and to provide a guideline for product category rules on incorporating carbon uptake in environmental product declarations (EPDs).

This project aims to investigate and develop the information and tools needed to move to higher levels of circularity. The outcomes of this project help the cement and concrete stakeholders better understand the extent of traditional and alternative material streams used for different applications such as clinker and fossil fuels replacement, and carbon mineralization, on a regionally specific basis. CSHub will develop a database and tool of end-use resource requirements to better match emerging sources for alternative virgin and waste materials and their highest value end-use markets for different regional contexts in the US.

This project is to create a platform that maps operational data in ready-mix facilities to GHG emissions. The developed platform analyzes the relationship between operational practices and GHG emissions and identifies opportunities to improve operational efficiency, waste, and associated GHG emissions, as well as characterizes the reduction sources. For this specific project, our vision is that real-time information on GHG emissions will provide new opportunities to engage other stakeholders – owners, designers, structural engineers, contractors, and code developers – on the role they can play in improving the value chain efficiency and avoiding overdesign.

Targeting the architectural and engineering design community, this project aims to develop a streamlined building LCA tool using an underspecification approach. The underspecification approach provides insight on how to conduct a robust life cycle assessment of buildings with minimal input data and at the early stages of the building design. The outcome of this project is an analytical tool that enables the users to quantify the uncertainty in the assessment and provide information on the parameters that most influence the life cycle emissions, which will provide a basis for more advanced optimization approaches.

While classical functionalities of concrete mixtures are associated with strength, ease of placement, and costs of concrete, this project addresses the versatility of concrete in the incorporation of new functionalities into the infrastructure systems and buildings. In this project, the environmental benefits of concrete will be improved by adding the capacity to store and buffer renewable energy. Enabled by incorporating low-cost carbon black in concrete, the outcome of this project can make the multifunctional concrete a commercially attractive capacitor, which is a key need for expanded renewable power generation.

Application Areas

Increasing urbanization means that policies enacted in cities are critical to mitigating the effects of climate change, urban heat island (UHI) effects, and natural or man-made disasters. CSHub research analyzes the economic, environmental, and hazard resistance impacts of building configuration and design in urban environments. This includes studying the UHI effect, which is defined as a temperature difference between urban areas and their rural surroundings where the city temperature is higher, and investigating ways to make cities more energy-efficient.

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There are many factors that must be considered before evaluating claims that one or another building type or product offers a better environmental return. To understand the full environmental impact of a structure over decades of use, all phases, starting before construction and continuing through demolition, must be considered. Life cycle assessment (LCA) seeks to quantify the environmentalimpacts over the infrastructure life cycle by identifying the costs during each phase.

LCA can be used to obtain credits in certification systems like LEED, but traditional LCA methods can be time, resource, and data-intensive. For complex systems like residential buildings, these demands can lead to delayed assessments with evaluations carried out after important design decisions have already been made, reducing their effectiveness. CSHub researchers have developed a streamlined approach to LCA that requires significantly less time and data, which can reduce expense as well as uncertainty and allow assessments to be conducted earlier in the building design process when decisions can have the greatest impact.

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A life cycle cost analysis (LCCA) is an analysis methodology that enables engineers, designers, and decision-makers to better understand the economicimpacts of infrastructure decisions over time along with the opportunities that exist to reduce impacts. CSHub buildings LCCA research considers life cycle, context, and future, and also incorporates costs due to anticipated hazards.

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Concrete sustainability begins at the most fundamental level: understanding the molecular structure of cement paste—calcium-silicate-hydrate (C-S-H), the main product of the hydration of portland cement and the primarily responsible for strength in cement-based materials.

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Carbon uptake, or carbonation, is a natural process of permanently sequestering CO2 from the atmosphere by hardened cement-based products like concretes and mortars. Through this reaction, these products form different kinds of limes or calcium carbonates. This uptake occurs slowly but significantly during two phases of the life cycle of cement-based products: the use phase and the end-of-life phase. The CSHub is investigating the impact of carbon uptake on concrete’s life cycle.


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Circular technologies like alternative fuels and recycled aggregates can enable a circular value chain for the cement and concrete industries.

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Clinker, the residue formed by high-temperature burning of coal or similar materials, plays an important role in the composition of cement and contributes to the properties of cement in different ways. Our research provides a fundamental understanding of the relationship between the surface energy of cement phases (the phases in clinker) and their electronic structure using quantum mechanics-based simulations. Researchers use this knowledge to suggest strategies for modifying clinker materials to improve those materials and lower carbon dioxide emissions. The discoveries and validations made possible by CSHub models would have taken decades to achieve experimentally.

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The CSHub has long investigated multifunctional concrete, and has uncovered a way to store energy in a mixture of carbon black, cement, and water. The technology has potential applications towards bulk energy storage, on-road EV charging, self-heating pavements, energy-autarkic structures, and more.

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Life cycle assessment (LCA) considers all life-cycle phases from initial construction to demolition. For pavements, this includes the operation, maintenance, and end of life phases, and factors such as traffic delay, lighting demand, and future maintenance. CSHub models quantify environmental impacts across a pavement’s life cycle from manufacturing to disposal and offer detailed analyses of the use phase.

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A life cycle cost analysis (LCCA) is an analysis methodology that enables engineers, designers, and decision-makers to better understand the economic impacts of infrastructure decisions over time along with the opportunities that exist to reduce impacts. CSHub pavements LCCA research considers life cycle, context, and future, and also incorporates risk.

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Pavement vehicle interaction (PVI) is a concept that looks at the interaction between a vehicle’s tires and the roadway surface on which it is driving. It is also known as rolling resistance. Three factors relating to a road’s surface condition and structural properties contribute significantly to PVI: roughness, which refers to how bumpy or smooth a road is; texture, the abrasiveness of the road surface; and deflection, the bending of a pavement under the weight of a vehicle. Traffic patterns and temperature are influential factors as well.

PVI leads to excess fuel consumption (EFC), which is wasted fuel consumption beyond what is required to move a vehicle. EFC contributes to smog and greenhouse gas emissions and impacts drivers, states, and municipalities financially.

CSHub research has led to models that quantify excess fuel consumption due to PVI for pavement segments and pavement networks.

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