In the quest for sustainable construction materials, a humble volcanic rock is making waves. Pumice, known for its lightweight and porous nature, is emerging as a game-changer in the concrete industry. A comprehensive review published by Karan Moolchandani of the Civil Engineering Department at Punjab Engineering College in Chandigarh, India, sheds light on the remarkable potential of pumice in creating next-generation concrete.
Pumice, with its high amorphous silica content, offers intrinsic pozzolanic reactivity and internal curing potential. This means it can enhance the long-term performance of concrete, making it a viable option for both structural and non-structural applications. Moolchandani’s review, which synthesizes insights from over 60 recent studies, reveals that replacing up to 25% of cement with pumice can significantly improve late-age compressive strength by 6–11%. This is a substantial boost, considering the concrete’s strength typically increases slowly after the initial setting period.
But the benefits don’t stop at strength. Pumice also reduces chloride permeability by 22–35% and improves sulfate resistance by up to 28%. This is crucial for structures exposed to harsh environments, such as coastal regions or areas with high sulfate soils. “Pumice’s porous morphology allows it to absorb and release water, which helps in mitigating autogenous shrinkage and improving the durability of concrete,” Moolchandani explains. In fact, using pumice as an aggregate can reduce autogenous shrinkage by as much as 75%.
The energy sector stands to gain significantly from these advancements. Pumice–PCM (Phase Change Material) systems can lower thermal conductivity by 30–56% and reduce surface temperatures by up to 42%. This means buildings can stay cooler in hot climates, reducing the need for air conditioning and lowering energy consumption. Moreover, pumice’s lightweight nature can decrease the structural load, allowing for more efficient use of materials and energy in construction.
However, the journey towards widespread adoption of pumice-based concrete is not without challenges. Early-age strength limitations, workability loss, and freeze–thaw vulnerability are key hurdles that need to be addressed. Moolchandani’s review identifies gaps in calorimetric analysis, ITZ (Interfacial Transition Zone) evolution, and application-specific design protocols, paving the way for future research.
As the construction industry grapples with the need for sustainable and low-carbon materials, pumice presents a compelling solution. Aligned with circular economy and climate resilience objectives, pumice-based concrete could shape the future of construction. The review, published in the journal Next Materials, which translates to Next Generation Materials in English, provides a roadmap for harnessing the full potential of this volcanic rock. As Moolchandani puts it, “The future of concrete is not just about strength and durability, but also about sustainability and resilience. Pumice offers a path towards that future.” The ball is now in the court of researchers, engineers, and policymakers to turn this potential into reality.