Foam concrete, also called cellular concrete, is typically made of water, cement and foam. This mixture may also include aggregates or chemicals added to change its physical properties. It is a lightweight material with low density and limited strength in most applications. It is typically a self-levelling and compacting material that is more resistant to cracking and shrinkage than standard concrete mixes. Some foam concrete mixes include Portland cement that is mixed with the cement and foam by itself or mixed with pulverized fly ash. It may also include limestone. Each of these mixtures makes a cement product ideal for different applications, but typically all foam concrete products become more resistant when compressed and aren't vulnerable to liquefication or settlement once hardened.