Structural lightweight concrete

The use of structural lightweight concrete in shipbuilding The use of structural lightweight concrete in bridge construction and reconstruction of bridges The use of structural lightweight concrete in the process of building and creating more resistance against earthquake The use of structural lightweight concrete in precast industry The use of structural lightweight concrete in the construction of offshore structures

Recently Nano Technology has been introduced in Civil Engineering applications. One of the most used nano material is Nano Silica (NS). This is the first Nano product that has replaced the micro silica. The advancement made by the study of concrete at nano scale has proved that nano silica is much better than silica fume used in conventional concrete. Nano silica possess more pozzolanic nature, it has the capability to react with the free lime during the cement hydration and forms additional C-S-H gel which gives strength, impermeability and durability to concrete.

Structural lightweight concrete has an in-place density (unit weight) on the order of 1400 to 1900 kg/m3 compared to normal weight concrete with density in the range of 2000 to 2400 kg/m3. For structural applications the concrete strength should be greater than 17 MPa. The concrete mixture is made with a lightweight coarse aggregate. In some cases a portion or the entire fine aggregate may be a lightweight product. Lightweight aggregate used in structural lightweight concrete are typically expanded shaleو clay or slate materials that have been fired in a rotary kiln to develop a porous structure.