“What is Air-crete? Air-crete is a lightweight cementitious material that contains stable air cells uniformly distributed throughout the mixture. It is a concrete which utilizes a stable air cell rather than traditional aggregate. It is also called cellular concrete, foam concrete, light weight concrete, aerated concrete etc. Typical concrete has a density of 140 lb/cu.ft. Air-crete densities range down to 20 lb./cu. ft.
What is the correct water to cement ratio for the cement water slurry?
Typically, a (1 to 2) water to cement ratio slurry is used as a base mixture for Air-crete. The water cement ratio may be varied according to specific project requirements.
Does Air-crete contain either fine or course aggregate?
Air-crete may contain sand but not coarse aggregates. Air-crete is designed to create a product with a low density and a relatively lower compressive strength when compared to plain concrete. The typical density range of Air-crete is 20 – 60 lbs/cu.ft. which develops a corresponding compressive strength range of 50 psi – 930 psi. When higher compressive strengths are required, the addition of fine and less foam will result in a stronger concrete with resultant higher densities.
What type of cement is appropriate for Air-crete? Air-crete may be produced with any type of portland cement or portland cement & fly ash mixture. The performance characteristics of type II, type III and specialty cements carry forward into the performance of the Air-crete.
What are the advantages of Air-crete? There are many benefits to Air-crete in the appropriate application. It is inexpensive to produce, it has good compressive strength, it bonds well, easy to work with, self compacting, self leveling, uses less material, and offers enhanced sound and heat insulating properties. Air-crete is very easy to clean up and can be removed with only hand tools.”
More at the source: Dome Gaia
Here’s my take on this building system. First, I want to compliment them on their excellent video, photography and stunning design aesthetic. The fact that this home has been reposted on countless websites shows how popular it is. However, I do have some comments and questions:
– how thick are the dome walls? what is the R-value?
– the mixture is just cement, water and dish soap?
– it seems better to use a motor vs. burning up a good drill
– estimated time to construct the forms?
– estimated time to construct one dome with 2 skilled masons with air-crete? size of dome?
– do you use steel reinforcement?
– if air-crete is waterproof, why do you recommend using waterproofed plaster?
– how do you prevent the dome from turning black with mold in rainy climates?
– Cement products absorb moisture. Do you add something special to repel water?
– due to the specialized nature of this system, it seems best for contractors who are building lots of houses.