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General Forums => Personal Blogs => Topic started by: Enthalpy on April 02, 2023, 11:51:19 AM

Title: Cement and Concrete without Carbon Dioxide
Post by: Enthalpy on April 02, 2023, 11:51:19 AM
Hi dear friends!

The transport and energy sectors find or adopt solutions, but buildings construction still emits CO2. The amounts are big, progress is imperceptible.

Cause is the production of lime from CaCO3 to CaO by heat. While heat can be clean, the release of CO2 by the reaction seems inevitable. CaO serves then to make cement, concrete etc, I believe by reacting with silica and aluminosilica plus water to make hydrated calcium silicates that bind stones, gravel, sand.

Can this improve?

Ceramic-based glues can bind stones, ceramics and more. They typically contain a fine (dehydrated?) ceramic powder in water, sometimes with other volatile liquids. They seem stronger than concrete. Examples (competition exists):
  Ceramabond by Aremco (https://www.aremco.com/ceramic-adhesives/)

Some adhesives are expensive by composition, like ZrO2. Others use Al2O3, SiO2, MgO. A small glue pot sells for 100usd presently. But the production involves "only" purification, pulverizing, dehydration by heat that can emit no CO2. I hope the other steps can become cheap after a true effort of research and industrialization.

Most such glues need heat to set. Some, including Al2O3 and MgO, accept just under 100°C for 2h. This demands a limited adaptation effort by the construction sector and saves even time and constraints over present methods.

The importance is huge. Your turn! Ideas, suggestions, proposals, comments, opinions even diverging, rants...?

Marc Schaefer, aka Enthalpy