Post by sianski

Thanks again to Martin Butler for another heartening article about good science.

Waste not, want not.
This piece is about the recycling of diapers to build roads, would you believe.
Here are the facts:

‘The Netherlands Builds Roads from Recycled Diapers That Last Longer Than Asphalt

At the edge of a Dutch suburb outside Eindhoven, a new bike lane curves through the trees. It looks ordinary — black surface, smooth edge, painted line. But underneath, the foundation layer is anything but standard. It’s made of used diapers — thousands of them, shredded, sterilized, and pressed into long-lasting road base. This is diapercrete, developed in the Netherlands to build roads and walkways using one of the world's most overlooked waste streams.

Engineers at the HAN University of Applied Sciences and local recycling firm CirTec have developed a multi-stage process to repurpose disposable diapers, which are typically landfilled or incinerated. First, the diapers are steam-sterilized at high pressure to eliminate pathogens and separate layers. The plastic backsheet, absorbent core, and cellulose liner are then processed into three usable materials: polymer filler, thermal insulation, and hydrophilic gel granules.

The most durable portion — the polypropylene and polyethylene fibers — is used to form a load-distributing geotextile that replaces traditional sand and gravel sublayers in roads. This layer resists shifting, absorbs pressure, and drains excess water, reducing erosion and pothole formation. It also weighs 30% less than gravel, making installation faster and cheaper.

In pilot installations, diaper-based roadbeds have shown 20–25% greater longevity than standard materials, especially in high-moisture areas. Tests on rural paths and bike trails show reduced subsidence, better drainage, and lower maintenance frequency. The embedded gel layers even regulate subsurface moisture, keeping frost from expanding cracks during freeze-thaw cycles — a persistent problem in Dutch winters.

At the CirTec test yard, a technician inspects a section of bike path, gently pushing a sensor probe into the surface. The Dutch flag is stitched on her high-vis jacket, and another flag appears printed on the side of a bin full of sterilized fluff pulp. Around her, crates of recycled diaper material sit beside heavy rollers and paving samples — the future of infrastructure stacked like soft bricks.

This isn’t just trash turned useful. It’s infrastructure born from what we throw away.’