Physical and functional characteristics of foam concrete: A review

With the increase in global warming, the construction sector is trying to find an alternative to ordinary concrete due to its high dead weight and thermal conductivity. Researches are going in different directions and presently the emerging trend is the use of foamed concrete, which is a lightweight concrete having more strength-to-weight ratio with density varing from 300 to 1800 kg/m3. This reduces the dead load on the structure, cost of production and labour cost involved during the construction and transportation. Also, the large number of pores in the foam concrete reduces the thermal and sound absorption, thus making the structure appropriate for all climatic conditions. The paper reports an in-depth review of foamed concrete in terms of its components, fresh state and physical properties like consistency, stability, workability, drying shrinkage, air-void system and water absorption. It also includes a brief review of foam concrete prepared using various types of foams such as chemically expanded and air cured foams. Various mechanical properties like compressive strength, flexural strength and elastic modulus are also discussed. In addition, to have more understanding about the variable aspects that promote a better habitable atmosphere for all climatic conditions functional characteristics like thermal conductivity, fire resistance, acoustic properties and resistance to aggressive environment are also presented. Apart from this, the paper reports a brief outline of various applications of foam concrete.