A recent study has shown that adding a small amount of zinc peroxide nanoparticles (ZP-NP) can significantly enhance the strength, density, and durability of lightweight foamed concrete.
Study: Comprehensive evaluation of mechanical, durability, and microstructural properties of foamed concrete with zinc peroxide nanoparticles. Image Credit: Contentino/Shutterstock.com
Published in Scientific Reports, the research explores how ZP-NP can address the longstanding limitations of traditional foamed concrete, namely, its low compressive strength and high porosity, by examining improvements in its mechanical, thermal, and microstructural properties.
Nanotechnology’s Role in Improving Foamed Concrete
Foamed concrete is a lightweight material made by introducing a foaming agent into a cement-based mix, creating air voids that give it excellent thermal insulation and reduced weight. These characteristics make it useful across various construction applications.
However, its benefits come with trade-offs. High shrinkage, cracking, and limited mechanical strength have long been challenges. Nanotechnology, especially the use of highly reactive, high-surface-area particles like zinc peroxide nanoparticles, offers a potential solution here. ZP-NP can accelerate hydration, refine the pore structure, and boost both mechanical performance and long-term durability.
Experimental Design and Testing Procedures
To test ZP-NP’s effectiveness, researchers created five concrete mixes: a control and four others with increasing ZP-NP content (1 %, 2 %, 3 %, and 4 %). All used Ordinary Portland Cement, fine sand, distilled water, a protein-based foaming agent, and ZP-NP, with consistent binder-to-sand (1:1.5) and water-to-binder (0.50) ratios. Nanoparticles were uniformly dispersed using ultrasonic methods.
Concrete samples were cured in water and tested at 7, 28, and 56 days for various properties:
- Workability (slump and setting time)
- Mechanical strength (compressive, flexural, and splitting tensile)
- Dry density and porosity
- Thermal properties (conductivity and heat capacity)
- Drying shrinkage
- Microstructure, analyzed through SEM and mercury intrusion porosimetry (MIP)
Key Findings: Performance Boost with Optimal Dosage
The results were clear, and ZP-NP was found to have a noticeable effect on nearly every property tested.
Workability slightly decreased with higher nanoparticle content, as slump values dropped modestly from 25.10 mm in the control to 24.00 mm at 4 % ZP-NP. However, setting times shortened, with the 4 % mix showing a 20 % faster initial set attributed to accelerated hydration triggered by the nanoparticles.
When it came to strength, the 2 % ZP-NP mix stood out as the optimal formulation. At this concentration, compressive strength increased to 5.89 MPa at 56 days, compared to just 4.21 MPa in the control. Splitting tensile and flexural strengths followed a similar pattern, each rising by over 60 %. Beyond 2 %, however, performance dropped off, likely due to the agglomeration of excess nanoparticles, which created weak points within the concrete matrix.
Density improved across all nanoparticle-enhanced mixes, while porosity declined. The 2 % mix showed a 6.66 % reduction in total porosity, along with the lowest drying shrinkage of all samples. Thermal conductivity also increased with ZP-NP, peaking at 2 % before tapering slightly at higher concentrations. Meanwhile, specific heat capacity decreased, suggesting enhanced insulation potential due to the denser matrix.
Microstructural analysis reinforced these findings. SEM images revealed a more compact, uniform internal structure in the nanoparticle-modified concrete, with smaller and better-distributed pores. MIP results further confirmed reduced pore volume and improved refinement, all contributing to the observed gains in strength and durability.
Implications for Construction
While the study didn’t focus on specific applications, the improvements suggest that ZP-NP-modified foamed concrete could be better suited for more demanding use cases. With its improved strength, lower shrinkage, and better thermal behavior, this material could be particularly valuable in precast elements, insulation panels, or components designed for humid or variable environments.
What’s especially notable is that these gains were achieved without sacrificing the core benefits of foamed concrete, including its light weight and insulating capacity. By optimizing nanoparticle content, particularly around the 2 % mark, engineers may be able to expand the use of foamed concrete into areas where it was previously unsuitable.
Where Research Goes From Here
This study provides strong evidence that zinc peroxide nanoparticles, when carefully dosed, can significantly enhance the mechanical and durability properties of foamed concrete. The 2 % concentration appears to be the sweet spot, delivering gains across all major performance metrics without triggering the drawbacks associated with overuse.
Future research should explore how this modified concrete performs under real-world conditions, including exposure to freeze-thaw cycles, chemical attack, and long-term loading. There’s also room to examine how other types of nanoparticles compare to ZP-NP in similar formulations, and whether these enhancements remain cost-effective at scale.
Journal Reference
Mydin, M.A.O., &. et al. Comprehensive evaluation of mechanical, durability, and microstructural properties of foamed concrete with zinc peroxide nanoparticles. Sci Rep 15, 41777. DOI: 10.1038/s41598-025-25683-0, https://www.nature.com/articles/s41598-025-25683-0
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