From waste to high-performance building material

May 30, 2025

In a noteworthy development toward merging sustainability goals with civil engineering, Japanese researchers have invented a new soil solidifier made entirely from industrial waste that has the properties of a high-strength soil binder, while lacking cement altogether, thus reducing cost and environmental impact when compared to traditional binding materials.

The innovation not only meets engineering performance standards, but also addresses two of the industry’s most significant issues—cement’s carbon footprint and industrial landfill waste—by using construction dust and recycled glass as filler material.

Activated and thermally treated, the resulting mixture delivers compressive strengths exceeding 160 kN/m², meeting construction-grade thresholds for soil stabilization under roads, buildings, and bridges.

“This research represents a significant breakthrough in sustainable construction materials,” notes Prof. Shinya Inazumi.

“By using two industrial waste products, we developed a soil solidifier that not only meets industry standards but also helps address the dual challenges of construction waste and carbon emissions.”

A greener path to infrastructure developmen

Ordinary Portland Cement (OPC), the industry’s go-to soil stabilizer, is responsible for 7–8% of global carbon emissions. Meanwhile, industrial waste such as construction dust and glass continues to accumulate in landfills. The Japanese team’s innovation aims to solve both problems with a single material.

The breakthrough hinges on processing SCP at specific temperatures—110°C and 200°C—to enhance its chemical reactivity while reducing the quantity needed. When mixed with Earth Silica, the geopolymer blend solidifies soil without OPC.

Inazumi explains, “Sustainability cannot come at the expense of environmental safety. Most importantly, we identified and solved a potential environmental concern: when arsenic leaching was detected in initial formulations, we demonstrated that incorporating calcium hydroxide effectively mitigated this issue.”

He adds, “In urban infrastructure development, our technology can stabilize weak soils beneath roads, buildings, and bridges without relying on carbon-intensive Portland cement.

This is particularly valuable in areas with problematic clay soils where conventional stabilization methods are costly and environmentally burdensome.”

From emergency response to global construction

Beyond its sustainability, the new material offers practical advantages. It sets quickly, has excellent workability, and resists damage from environmental stressors like freeze-thaw cycles, sulfates, and chlorides, making it ideal for emergency soil stabilization in disaster zones as well as long-term infrastructure in harsh environments.

For rural development, the material could even be used to produce low-carbon soil blocks of the kind produced in previous endeavors, offering an alternative to carbon-intensive fired bricks or concrete.

Inazui emphasizes the broader vision behind his work: “By developing a geopolymer solidifier from readily available waste streams, we are not only offering a sustainable engineering solution but redefining how we value industrial byproducts in a resource-constrained world.”