TecEco Gaia Engineering Technologies
TecEco Gaia Engineering technologies include any technologies on our web site that are sustainable including those under the Syncarb banner dealing more specifically with the Syncarb project for recyling CO2 and Carbonsafe banner which deals with making products from the output of Syncarb and any of our other technologies.
The TecEco Cement System is an example of Gaia Engineering
TecEco Cements comprise a blending system of hydraulic cements such as ordinary Portland Cement and reactive magnesia[1] and usually also a pozzolan and were invented in response to technical problems exhibited by Portland Cement and the need for more sustainable binders. The range of new technically superior binders that have been developed include Tec, Eco and Enviro-cements.
Tec-Cements (5 -20% MgO, 80 – 95% PC) contain more Portland Cement than reactive magnesia[1]. Reactive magnesia[1] hydrates in the same rate order as Portland Cement forming Brucite which uses up water reducing the voids:paste ratio, increasing density and possibly raising the short term pH. Reactions with pozzolans are more affective and we recommend the removal of lime (which is far to mobile and reactive to be left in a durable binder) in this manner. After all the Portlandite has been consumed Brucite and CSH control the long term pH which is lower and due to its low solubility, mobility and reactivity results in greater durability. Other benefits include improvements in density, strength and rheology, reduced permeability and shrinkage and the use of a wider range of aggregates many of which are potentially wastes without reaction problems.
Eco-Cements (20-95% MgO, 80-5% PC) contain more reactive magnesia[1] than in Tec-Cements. Brucite in permeable materials carbonates forming stronger fibrous minerals and therefore presenting huge opportunities for waste utilization and sequestration. Portland cement is the catalyst.
Enviro-Cements (20-95% MgO, 80-5% PC) contain similar ratios of MgO and PC to Eco-Cements but in non permeable concretes brucite does not carbonate readily. Higher proportions of magnesia[1] are most suited to toxic and hazardous waste immobilization and when durability is required. Strength is not developed quickly nor to the same extent.
Technical issues addressed by the new TecEco Cement technology include:
- Durability
- Sulphate and chloride resistance
- Carbonation
- Corrosion of steel and other reinforcing
- Delayed reactions (e.g. alkali aggregate and delayed ettringite)
- Freeze-thaw
- Rheology
- Workability, time for and method of placing and finishing, stick and rebound with mortars.
- Dimensional change including shrinkage
- Cracking, crack control
- Bonding to brick and tiles
- Waste immobilization and utilization
- Efflorescence
Concretes are already a relatively sustainable material. With low cost high thermal capacity they supply essential thermal mass to buildings. With the advent of TecEco technology, concretes will offer greater opportunities for sustainability with other improved properties such as:
- Improved insulation
- Lower binder aggregate ratios
- Greater durability
- Lower embodied and lifetime energies
- Waste utilization
- Abatement and sequestration
printer friendly
[1] Reactive magnesia is also variously known as caustic calcined magnesia, caustic magnesia or CCM. The temperature of firing has a greater influence on reactivity than grind size as excess energy goes into lattice energy.