In use for more than four decades, light weight concrete has proven in its principle for economy and benefits over the years of usage, writes M.V.S.Giridhar

As an effective technology, light weight concrete not only promises to reduce the weight on a concrete structure but also minimises the heat transfer from atmosphere to concrete surface such as terrace and fills in voids. It is also cost effective, faster, better and long lasting.

In use for more than four decades, light weight concrete has proven in its principle for economy and benefits over the years of usage. Synonymous to foamed or aerated concrete, it is also a green product and the densities could be varied from 400 to 1600 kgs/m3 based on the application.

Fly ash, cement and silica are the key ingredients of this building material which coming with good mechanical strength and low thermal conductivity, ensures that simple but highly technological processing can be done directly at a given site.

Also, the concrete contains confined air pockets which reduce its weight substantially and achieves savings in structure.

How it works

Light weight concrete perfectly fills the space, reduces the weight on the structure, reliably transfers the load and functions as thermal and acoustic insulating layer. The table below shows that broadly speaking the K value for light weight concrete lies between 0.08 w/mk at the lower densities and 0.62 w/mk at higher densities.

The technology could also be described as an exceptionally economical process since it comes with advantages such as high productivity, low manipulation and labour costs, less number of workers and substantially reduced construction time.

Light weight concrete of 500 to 600 kgs/m3 density for floor screed is an extremely good underlay for making good levelled floor for laying ceramic and vitrified tiles, wooden plank floor, carpeting by vinyl or fibre.

The key advantage being less weight on the SLAB (concrete structure), transfer of sounds from top floor to bottom floor reduced due to acoustic insulation properties, faster pace construction and it forms an ideal surface.

The system of it include consistent and fine pore texture at different densities, low water uptake, strength gain early and good 28 days compressive strengths, good thermal and acoustic properties apart from wide range of rheological, adhesive and thin-set properties.Due to wet production process and possible selection of required mechanical and physical properties, lightweight concrete is also used as fillers in various spaces with densities ranging from 400 to 1,000 kgs/m3 and certain others areas such as sunken bath rooms, stabilization of voids, abutment walls, pouring out dead spaces with complicated shape, pouring outer walls of swimming pools, sports arena and roof top gardening.

(The writer is a consultant in city and can be contacted at ‘' )