Futuristic city skyline built with sustainable carbonated concrete.

Green Concrete: Can Carbonation Make Cement Stronger and More Sustainable?

Samir D’Costa in Climate & Environment August 2025 • 4 min read.

"Explore how early age carbonation is revolutionizing cement composites, enhancing their mechanical properties and durability for a greener future."

The construction industry is constantly seeking innovative methods to enhance the strength and longevity of building materials while minimizing environmental impact. Recent research has focused on the potential of early age carbonation to improve the mechanical properties and durability of cement and lime-based composites. These techniques not only promise stronger construction but also offer a sustainable approach by capturing carbon dioxide, a major greenhouse gas.

Carbonation, in simple terms, is the process where carbon dioxide (CO2) reacts with the components of cement or lime, leading to the formation of carbonates. This reaction can significantly alter the material's microstructure, affecting its strength, porosity, and resistance to degradation. By controlling this process during the early stages of curing, engineers can tailor the properties of the composite to meet specific performance requirements.

This article delves into the fascinating world of carbonation in cement composites, exploring the science behind it, the benefits it offers, and the potential it holds for revolutionizing the construction industry. We'll examine how this method is being applied to high initial strength Portland cement and lime-pozolan composites, particularly those reinforced with long sisal fibers, to create more sustainable and durable building materials.

How Does Early Age Curing Carbonation Work?

Futuristic city skyline built with sustainable carbonated concrete.

Early age curing carbonation involves exposing cement-based materials to a CO2-rich environment during their initial setting and hardening phase. This controlled exposure triggers a series of chemical reactions that enhance the material's properties. The primary reaction involves CO2 reacting with calcium hydroxide (CH), a byproduct of cement hydration, to form calcium carbonate (CaCO3).

This process has several key benefits:

Increased Strength: The formation of CaCO3 fills the pores within the cement matrix, making it denser and stronger.
Enhanced Durability: Carbonation reduces the alkalinity of the cement, making it less susceptible to chemical attacks and degradation.
CO2 Capture: It actively captures and utilizes CO2, turning a greenhouse gas into a beneficial component of the building material.
Improved Microstructure: The resulting material exhibits a refined microstructure, contributing to its overall performance.

Researchers have been exploring different methods to optimize this process, including varying the CO2 concentration, exposure time, and curing conditions. The goal is to achieve the ideal balance that maximizes strength and durability while ensuring the process remains economically viable and environmentally sustainable.

The Future of Carbonated Composites

Early age carbonation holds immense potential for transforming the construction industry, offering a pathway to create stronger, more durable, and environmentally responsible building materials. As research continues to refine these techniques and explore new applications, the vision of a greener, more sustainable construction sector becomes increasingly within reach. By embracing these innovative approaches, we can build a future where our infrastructure contributes to a healthier planet.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.compositesb.2018.11.006, Alternate LINK

Title: Effect Of Early Age Curing Carbonation On The Mechanical Properties And Durability Of High Initial Strength Portland Cement And Lime-Pozolan Composites Reinforced With Long Sisal Fibres

Subject: Industrial and Manufacturing Engineering

Journal: Composites Part B: Engineering

Publisher: Elsevier BV

Authors: Alex Neves Junior, Saulo Rocha Ferreira, Romildo Dias Toledo Filho, Eduardo De Moraes Rego Fairbairn, Jo Dweck

Published: 2019-04-01

Everything You Need To Know

What is early age carbonation, and how does it improve cement-based materials?

Early age carbonation is a process where cement-based materials are exposed to a CO2-rich environment during their initial setting and hardening phase. This controlled exposure triggers chemical reactions, primarily where CO2 reacts with calcium hydroxide (CH), a byproduct of cement hydration, to form calcium carbonate (CaCO3). This process improves the mechanical properties and durability of materials like high initial strength Portland cement and lime-pozolan composites by increasing their strength, enhancing their durability, capturing CO2, and improving their microstructure.

How does carbonation affect the microstructure of cement and lime-based composites?

Carbonation significantly alters the microstructure of cement and lime-based composites. The reaction between CO2 and components like calcium hydroxide (CH) leads to the formation of calcium carbonate (CaCO3). This formation fills the pores within the cement matrix, making the material denser. The refined microstructure contributes to overall performance improvements, including increased strength and enhanced resistance to degradation and chemical attacks. This leads to improved durability and longevity of the building materials.

What are the primary benefits of using early age carbonation in construction?

The primary benefits of early age carbonation include increased strength and enhanced durability of cement and lime-based composites. The formation of calcium carbonate (CaCO3) fills the pores, making the material stronger and less susceptible to degradation. Moreover, early age carbonation actively captures and utilizes CO2, converting a greenhouse gas into a beneficial component of the building material. This makes it a sustainable approach to construction. The resulting material also exhibits a refined microstructure, further contributing to its overall performance and the possibility of using materials reinforced with long sisal fibers.

How is the process of early age carbonation optimized for practical applications in the construction industry?

Researchers optimize early age carbonation by varying factors like CO2 concentration, exposure time, and curing conditions. The goal is to find the ideal balance that maximizes the strength and durability of cement and lime-based composites, such as high initial strength Portland cement and lime-pozolan composites. This optimization is crucial to ensure the process remains economically viable and environmentally sustainable. The precise control over these parameters allows engineers to tailor the properties of the composite to meet specific performance requirements, leading to more sustainable and durable building materials.

What is the potential impact of early age carbonation on the future of sustainable construction?

Early age carbonation holds immense potential for revolutionizing the construction industry, offering a pathway to create stronger, more durable, and environmentally responsible building materials. By capturing CO2, it directly addresses the environmental impact of cement production, making it a greener alternative. The application of this method, particularly in materials like high initial strength Portland cement and lime-pozolan composites, reinforced with long sisal fibers, could significantly reduce the carbon footprint of construction projects. This innovative approach promises a future where infrastructure contributes to a healthier planet, with the vision of a greener, more sustainable construction sector becoming increasingly within reach.