Q: Can the production cost of a slab, beams and walls be reduced by the use of lightweight concrete in comparison to conversional concrete?

A: (Kelly) I doubt that the use of lightweight concrete will actually reduce the cost of a project. It is lighter and more insulating, but is also less strong in compression. The aggregate might actually cost more, depending the the resources available in your locality.

Q: I know that building costs will depend on area and type of construction. Are you able to give me a rough ball park comparison between typical "stick built" or prefab and concrete construction - such as pumicecrete? We are wanting to build such buildings for our art school and I am putting a fundraising letter together. Want to give some cost comparisons to our supporters.

A: (Kelly) Much of the cost of construction with either approach is the same. A stick-built wall might be a bit less expensive, because it is so standard that the trades people are all set up for this approach. The difference might be about 5% at the most. But a lightweight concrete building would be much more substantial, probably last longer, and be somewhat more earth-friendly.

Q: I was in Kashgar China to look at magnesia cement, perlite panels, light weight concrete. The product is good .6m x 3m x .15m . The cost however including shipping and taxes comes to $14 sq meter. The cost of technology, astronomical. I want the product for the earth quake areas, the idea is not to make a lot of money but to support and develop a sustainable system. Have experimented with mgo mgcl and perlite, got no where. Please suggest a line of action.

A: According to the e-mail the problems that this gentleman has are: cost of technology and physical behavior of material at site, therefore what I recommend is for him to produce my aggregate so he can have a sustainable source of lightweight aggregate for him to produce the elements of concrete that he needs. In order to quote this gentlemen what will be his cost in producing this aggregate I will need the following data:
1.-Capacity required per year
2.-Cost of following local materials: a.- Cement cost/lb or per kg; b- Gypsum cost/lb or per kg; c- Natural sand cost/lb or per kg.
With this data I can tell him what will be his cost per ton of aggregate (Material Only); from here he can calculate his indirect costs + time of amortization of equipment, etc. And if he needs to have a total cost in manufacturing lightweight concrete we can help him if required. In other words he will have the flexibility to produce as much lightweight concrete as needed.