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. This led to the development of related lightweight concrete which are now known as cellular concrete, foamed concrete, aerated concrete and autoclaved cellular concrete.
After the Second World War, this technology quickly spread to different parts of the world, mostly Europe and the Soviet Union. The applications were for economical large-size structural panel units. These were used in site reconstruction and low-rise structures. It wasn’t till the late 1950’s when this was introduced to the US as foamed or cellular concrete. The applications were for floor, roof and wall units. Having low compression strengths, it limited this product to fills and insulation only.
The major use in recent years in the United States has been over plywood on wood floor systems or over hollow-core precast slabs. The material is also used in light density for roof fills 481 kilograms per cubic meter [30 pounds per cubic foot] providing good insulating properties. Even today this material still generate low compressive strengths limiting it to these two applications. Range options are 3.45 MPa [500 psi] to 6.89 MPa [1,000 psi] for midrange nonstructural densities and 10.3 MPa [1,500 psi] to 24.1 MPa [3,500 psi] for higher densities 1762 kg/m³ [110 lb/ft³].
Concrete design has evolved rapidly in the last 30 years. Construction technology has seen the introduction of a variety of concrete products to the market as well as an increased use of supplementary cementitious materials and recently blended cements. Emphasis has been placed on creating more durable concrete through changes to the mix constituents and proportions, including the aggregates, admixtures and the water-cement ratio. These changes have been reflected in national and hopefully will lead to global/International design, standards, performance specifications and codes which address such factors as performance, durability, permeability, cement constituent ratios, and limitations on impurities. This evolution, along with improved reinforcing steel strength, has lead to modifications in design philosophy - most notably the use of thinner structural members.
As for a lower weight of these structural members, there are many applications for which a 1602 kg/m³ [100 lb/ft³] or lower structural concrete would be beneficial. With normal lightweight concrete in the 1,442 - 1,681 kilograms per cubic meter [90 - 105 pounds per cubic foot] range requires lightweight fine aggregate as well as coarse. When natural sand is used with lightweight coarse aggregates, strengths of 34.5 - 48.3 megapascals [5,000 - 7,000 pounds per square inch] can be obtained but the weight runs from 1,842 - 2,002 kilograms per cubic meter [115 to 125 pounds per cubic foot] adding to the weight. With High Performance Cellular Concrete [HPCC] the weight is significantly reduced to a 1041 - 1522 kilograms per cubic meter [65 to 95 pounds per cubic foot] with a 34.5 to 48.3 megapascals [5,000 - 7,000 pounds per square inch] resulting in improved structural efficiency in terms of strength/weight ratios, with fewer structural components, and a consequent reduction in the number and size of reinforcements. Panel width can be manufactured as thin as 63.5 millimeters [2.5 inches].
It is ideally suited for precast concrete products as larger units can be handled with the same handling equipment or manually for same size units, resulting in speed and economy in construction. These units in addition to smaller ones can be lifted or managed by down-sizing machinery resulting in reducing site cranage requirements and maximizing the number of concrete elements on trucks without exceeding highway load limits reducing transportation delivery cost.