Foam concrete

[3][4][5] Following this research, new admixtures were developed in the late 1970s and early 80s, which led to the commercial use of foamed concrete in construction projects.

It offers significant thermal and acoustic insulation and can be cut, carved, drilled and shaped with wood-working tools.

The foaming agent must be able to produce air bubbles with a high level of stability, resistant to the physical and chemical processes of mixing, placing, and hardening.

[1] Foam concrete compounds utilising fly ash in the slurry mix is cheaper still, and has less environmental impact.

It is therefore important to ensure that the air entrained into the foamed concrete is contained in stable, very tiny, uniform bubbles that remain intact and isolated, and do not thus increase the permeability of the cement paste between the voids.

[14] In recent years foamed concrete has been used extensively in highways, commercial buildings, disaster rehabilitation buildings, schools, apartments and housing developments in countries such as Germany, USA, Brazil, Singapore, India, Malaysia, Kuwait, Nigeria, Bangladesh, Botswana, Mexico, Indonesia, Libya, Saudi Arabia, Algeria, Iraq, Egypt, and Vietnam.

Foamed concrete has been investigated for use as a bullet trap in high intensity US military firearm training ranges.

[15] This work resulted in the product SACON being fielded by the U.S. Army Corps of Engineers, which when worn out, can be shipped directly to metal recycling facilities without requiring the separation of the trapped bullets, as the calcium carbonate in the concrete acts as a flux.

[16] The energy absorption capacity of foamed concrete was approximated from drop testing and found to vary from 4 to 15 MJ/m3 depending on its density.