International Journal of Engineering Research ISSN:2319-6890(online),2347-5013(print) Volume No.5, Issue Special 1 pp : 37-43 8 & 9 Jan 2016 NCICE@2016 doi : 10.17950/ ijer/ v5i1/ 009 Page 37 Cellular Concrete & its facets of application in Civil Engineering S. Nandi, Arnab Chatterjee, Prantik Samanta, Tanushree Hansda Nandi & Associates (P) Ltd, 76/1, Shreerampur (N), Garia, Kolkata 700 084, India Email: nandi.and.associates@gmail.com Abstract -- Cellular Concrete is a cementitious paste of neat cement or cement & fine sand with a multitude of micro / macroscopic discrete air cells uniformly distributed throughout the mixture to create a lightweight concrete. The concrete is manufactured in two methods viz. First by mixing a pre- formed foam (surfactant) or mix-foaming agents mixture into the cement & water slurry with the hardening of concrete, the bubbles disintegrate leaving air voids of similar sizes. Second designated as Autoclaved Aerated Concrete (AAC), consisting of a mix of lime, sand, cement, water & an expansion agent. The bubble is made by adding expansion agents (aluminum powder or hydrogen peroxide) to the mix during the mixing process. This creates a chemical reaction that generates gas, either as hydrogen or as oxygen to form a gas-bubble structure within the concrete to be molded. Each mold is filled to one- half of its depth with the slurry. The gasification process begins & the mixture expands to fill the mold above the top similar to baking a cake. After the initial setting, it is cured under high-pressured-steam (180° to 210°C / 356°to 410°F) “autoclaved” for a specific amount of time to produce the final micro / macro-structure. HPCC has is an excellent insulator & significantly reduces the transfer of heat through concrete member. With a low water absorption, high tensile strength, high fire resistance & sound retention, this corrects deficiencies in the sand reducing bleeding. Besides structural forms cellular concrete finds application in as Flowable Fill or Controlled Low Strength Material (CLSM), Low Density Controlled Low Strength Material (LD-CLSM) which is a an engineered backfill material used as an alternative to compacted fill that can make backfill faster, being self- leveling, making total compaction within a few hours of placement. Compressive strengths can be adjusted according to the project requirements. Placing as a permanent material or permitting re-excavation at a later date is the paramount advantage of this material. Keywords: Cellular Concrete, CLSM, Foam Concrete, CLC, HySSIL 1. Introduction: Foam concrete, Aerated Concrete, Lightweight Concrete, Porous Concrete Foam concrete is a type of porous concrete. According to its features & uses it is similar to aerated concrete. Foamed concrete has been defined in several ways; indeed it has number of synonyms such as cellular concrete & there is confusion between foamed concrete & similar materials such as air-entrained concrete. A definition, cited by Jones (2005), is that foamed concrete is a cementation material having a minimum of 20 percent (by volume) of mechanically entrained foam in the plastic mortar. 1.1 The synonyms are: Gas or Aerated concrete, Lightweight concrete, Porous concrete. 1.1.1 Gas or aerated concrete, where the bubbles are chemically formed through the reaction of aluminum powder with calcium hydroxide & other alkalis released by cement hydration. 1.1.2 Lightweight Concrete  Light weight concrete - or foamed concrete - is a versatile material which consist primarily a cement based mortar mixed with at least 20% by volume air.  It has high flow ability, low self-weight, minimal consumption of aggregate, controlled low strength & excellent thermal insulation properties.  It can have a range of dry densities, typically from 400 kgm - 3 to 1600 kgm -3 & a range of compressive strengths 1 MPa to 15 MPa.  Foamed Concrete can be placed easily, by pumping, if necessary, & does not require compaction, vibrating or leveling.  It has excellent resistance to water & frost, providing a high level of both sound & thermal insulation. 1.2 History Cellular Concrete was first developed in Stockholm, Sweden in the early 1900’s. The original material was known as “gas concrete” to be used in producing heat-insulated building materials. After the Second World War, this technology quickly spread to different parts of the world, mostly Europe & in the Soviet Union. These were used in site reconstruction & in low- rise structures. The first comprehensive review on foamed concrete was presented by Valore in 1954 & a detailed treatment by Rudnai, Short & Kinniburgh in 1963, summarizing the composition, properly. Significant improvements over the past 25 years in production equipment & better quality surfactants (foaming agents) has enabled the use of foamed concrete on a larger scale. Significant improvements over the past 25 years in production equipment & better quality surfactants (foaming agents) has enabled the use of foamed concrete on a larger scale. The first large foamed concrete project in the UK was completed in 1980 at the Falkirk Railway Tunnel in Scotland. The first author was involved in the same from contractor’s side. Around 4500 m 3 of 1100 kgm -3 bulk density foamed concrete was placed in the annulus space surrounding the tunnel. The largest project in the UK required around 70,000 m 3 of 500 kgm -3 foamed concrete encapsulating the utilities supply pipe & cable in the road foundation at Canary Wharf, London, where also the first author was involved. Significant improvements in production