Concrete pillar damaged by microbial growth, being protected by a layer of zeolite.

Is Your Cement a Victim of 'Concrete Cancer'?: How to Fight Biodeterioration

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

"Uncover the hidden threat of biodeterioration in cement composites and learn how innovative zeolite additives can offer a sustainable shield."

Concrete, the cornerstone of modern infrastructure, faces an unseen enemy: biodeterioration. This gradual breakdown, driven by microorganisms, undermines the structural integrity of buildings, bridges, and essential infrastructure. Understanding this threat is the first step in safeguarding our built environment.

The process of biodeterioration is complex. It involves various microorganisms, notably bacteria and fungi, which colonize concrete surfaces. These organisms produce acids that dissolve the concrete matrix, leading to cracks and weakening of the material. Factors such as moisture, temperature, and the chemical composition of the concrete influence the rate and extent of this deterioration.

This article explores the science behind concrete biodeterioration, focusing on the role of Acidithiobacillus thiooxidans, a key player in the process. We will also investigate how the addition of zeolite, a natural mineral, can significantly enhance concrete's resistance to microbial attacks, providing a sustainable solution to prolong the lifespan of concrete structures.

The Science Behind 'Concrete Cancer': Understanding Biodeterioration

Concrete pillar damaged by microbial growth, being protected by a layer of zeolite.

Biodeterioration of cement composites is a multifaceted process driven by microorganisms that thrive in diverse environments. These microbes, including bacteria and fungi, colonize concrete surfaces and initiate a series of chemical reactions that degrade the material. The process often starts with the microbial production of acids, which dissolve the alkaline components of concrete.

One of the primary culprits in this process is Acidithiobacillus thiooxidans, a sulfur-oxidizing bacterium. This bacterium converts sulfur compounds into sulfuric acid, a highly corrosive substance that reacts with calcium hydroxide in the concrete. This reaction forms gypsum, which expands and causes cracking, ultimately weakening the concrete structure. The cycle continues as more microbes penetrate deeper, exacerbating the damage. Key aspects include:

Microbial Colonization: Microorganisms attach to the concrete surface, forming biofilms.
Acid Production: Bacteria like Acidithiobacillus thiooxidans generate sulfuric acid.
Chemical Reactions: The acid reacts with calcium hydroxide, producing gypsum and other expansive compounds.
Structural Damage: Expansion leads to cracking, loss of strength, and eventual disintegration of the concrete.

Environmental factors such as temperature, humidity, and the presence of nutrients significantly influence the rate of biodeterioration. Warmer temperatures and high humidity levels create optimal conditions for microbial growth, accelerating the deterioration process. Similarly, the availability of sulfur compounds and other nutrients fuels the activity of sulfur-oxidizing bacteria. Addressing these factors is crucial in mitigating biodeterioration and preserving the integrity of concrete structures.

Zeolite: A Sustainable Solution to Combat Concrete Biodeterioration

The addition of zeolite to concrete mixes is emerging as a promising strategy to enhance resistance against biodeterioration. Zeolite, a naturally occurring mineral with a porous structure, offers several benefits when incorporated into concrete. Its unique properties contribute to improved durability and longevity of concrete structures.

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: 10.1088/1755-1315/44/5/052025, Alternate LINK

Title: Biodeterioration Of The Cement Composites

Subject: General Engineering

Journal: IOP Conference Series: Earth and Environmental Science

Publisher: IOP Publishing

Authors: Alena Luptáková, Adriana Eštoková, Eva Mačingová, Martina Kovalčíková, Jana Jenčárová

Published: 2016-10-01

Everything You Need To Know

What is biodeterioration in concrete, and why is it a problem?

Biodeterioration in concrete is the gradual breakdown of concrete caused by microorganisms, such as bacteria and fungi. These organisms colonize concrete surfaces, produce acids, and lead to cracking and weakening of the material. This process compromises the structural integrity of buildings, bridges, and other infrastructure, leading to potential safety hazards and costly repairs or replacements.

Which microorganisms are primarily responsible for biodeterioration in concrete?

Various microorganisms, including bacteria and fungi, contribute to concrete biodeterioration. A key player is Acidithiobacillus thiooxidans, a sulfur-oxidizing bacterium. This bacterium is particularly harmful because it converts sulfur compounds into sulfuric acid, which corrodes the concrete.

How does Acidithiobacillus thiooxidans damage concrete?

Acidithiobacillus thiooxidans damages concrete by producing sulfuric acid, which reacts with calcium hydroxide, an essential component of concrete. This reaction generates gypsum, an expansive compound. The expansion caused by gypsum formation leads to cracking and weakens the concrete structure. This process allows further microbial penetration and exacerbates the damage, leading to the disintegration of the concrete over time.

What role does zeolite play in preventing concrete biodeterioration?

Zeolite, a naturally occurring mineral with a porous structure, can enhance concrete's resistance to biodeterioration. When added to concrete mixes, zeolite improves the material's durability and longevity. Although the exact mechanisms are complex, its unique properties contribute to mitigating the damaging effects of microbial attacks. Therefore, zeolite provides a sustainable solution to prolong the lifespan of concrete structures.

What environmental factors influence the rate of concrete biodeterioration, and why are they important?

Environmental factors such as temperature, humidity, and the presence of nutrients significantly influence the rate of concrete biodeterioration. Warmer temperatures and high humidity levels create optimal conditions for microbial growth, accelerating the deterioration process. The availability of sulfur compounds and other nutrients fuels the activity of sulfur-oxidizing bacteria like Acidithiobacillus thiooxidans. Understanding and addressing these factors are crucial for mitigating biodeterioration and preserving the integrity of concrete structures because they determine the speed and extent of concrete degradation.