Technology
How a block gets made.
From sourcing to curing, plus the performance data — labeled by what's measured, what's a target, and what's still to be confirmed.
Sourcing
Two delivery routes, no extra trucks.
Cement and limestone dust both come from Garadagh and travel together on one truck. Plastic bales and incinerator ash both come from Temiz Sheher's Balakhani site and travel together on a second. Microsilica, CO2 gas, and cellulose pulp are all sourced locally within Sumgait.
The waste-to-energy plant would otherwise pay to landfill the ash it hands us — supplying it to us instead saves that cost, at no charge to us. Plastic arrives as pre-sorted bales; we sort further by resin code and reject anything that isn't clean HDPE or PP.
Process
Four steps, in order.
Sort & shred
Plastic is dry visual-sorted by resin code — HDPE and PP only, no water tank, since wet plastic throws off the mix — then shredded. Incinerator ash is stockpiled outdoors on a sealed pad for a minimum of eight weeks before use.
Mix
Sorted plastic, weathered ash, limestone dust, cement, and small amounts of microsilica and cellulose pulp are combined in a pan mixer.
Press
The mix is pressed into a two-core hollow steel mold at full block scale, 390 × 190 × 190 mm.
Cure
Instead of curing in water, the pressed block sits in a sealed chamber under CO2 gas for 24 hours. The gas reacts with calcium in the cement and mineralizes into solid calcium carbonate inside the block.
Why the ash gets weathered first. Fresh incinerator ash contains small amounts of metallic aluminum, which reacts with the alkaline cement paste and can crack a block days after pressing. Every batch is weathered outdoors and checked — a visual inspection plus a bubble test — before it's used.
Front face, hollow CMU — to scale
Geometry
Why it's hollow.
Solid, at this density, the block would weigh roughly 25 kg — heavier than the standard stone block it's meant to replace. Two through-cores bring the calculated weight down to about 12.3 kg, roughly a 50% void ratio, while keeping a face shell of at least 32 mm on every wall.
| Gross dimensions | 390 × 190 × 190 mm |
|---|---|
| Core configuration | 2 through-cores |
| Core size (each) | 130 × 120 mm |
| Void ratio | ~50% |
| Min. face shell | 32 mm |
| Target weight | ~12.3 kg |
Performance
What's measured, what's a target.
Lab specimens are 160 × 40 × 40 mm solid blocks. The commercial product is a 390 × 190 × 190 mm hollow block. These are not the same thing, and we test and report them separately.
| Property | Status | Value |
|---|---|---|
| 7-day compressive strength, lab specimen | Measured | 5.1 MPa |
| 28-day compressive strength, lab specimen | Measured | 9.0 MPa |
| ASTM C129-17 minimum (reference) | Reference | 4.14 MPa |
| 24h CO2-cure strength, commercial block | Target | >5.0 MPa |
| Full-scale hollow block production | Planned | Not yet produced |
| Block weight | Calculated | ~12.3 kg |
| Thermal conductivity | Lit. projection | 0.45–0.50 W/mK |
| Fire classification, EN 13501-1 Class B | Target | Not yet tested |
| CO2 mineralized, per 10,000 blocks | Calculated | ~3.5 t |
How it works
Five mechanisms, explained plainly.
Mechanical interlock
The angular shape of the shredded plastic gets gripped by the hardened cement around it, similar to how gravel locks into ordinary concrete. Microsilica helps the cement bond more tightly to the plastic surface. Zhang et al., 2023
CO2 curing
Instead of a water cure, the pressed block sits in a CO2 atmosphere. The gas reacts with calcium hydroxide in the cement and mineralizes into solid calcium carbonate — the same mineral limestone is made of. Tu et al., 2018
Fire behavior
The ash is inert and pre-burned at roughly 1,000°C, and the plastic sits encased in a mineral matrix with limited oxygen. We're targeting EN 13501-1 Class B, but haven't tested for it yet.
Sound
Cement and plastic transmit sound differently, which should reduce how much passes through the wall. This hasn't been measured yet.
Self-healing
The mix carries more cement than fully reacts during curing. Moisture reaching a small crack later can trigger new mineral growth that seals it — a mechanism documented in published research on similar concretes. We haven't tested it on our own blocks yet. Lahmann et al., 2023
What we ruled out
Not every waste stream made the cut.
LDPE soft film
Flat, thin flakes that clump together in the mix and don't get coated properly by the cement paste.
Mixed cable scrap
Real-world cable scrap usually still carries PVC jacketing, which releases hydrogen chloride gas if it ever burns. Only cleanly stripped insulation would be safe, and we can't verify that without certification.
Cement kiln dust
Can carry trace heavy metals and would need leaching tests before use. Left out for now to keep the process simple.
PVC, in any form
Not accepted in any feedstock, full stop.
Environmental impact
Per 10,000 blocks, calculated.
Mass-balance figures from the formulation — to be confirmed once we're running at production scale.
~13.3 t
Plastic diverted
~24.6 t
Incinerator ash diverted
~47.9 t
Limestone dust diverted
~3.5 t
CO2 mineralized (stoichiometric estimate)
Questions about the chemistry or the specs?
We're happy to go deeper on any of this — formula direction, testing plans, or standards we're working toward.