Some trends for the construction of slabs industry

Concrete is undoubtedly one of the oldest and most widely used building material in the world. In one form or another various types of concrete have been used for construction purposes since time immemorial. New trends can be seen hitting the construction of slabs in today’s world.

Columns are a crucial part of most buildings. Load bearing columns, unfortunately, tend to be large. Though large columns can be fashioned and designed artistically, thus giving an aesthetically pleasing appearance, they often take up vital space and obstruct free movement as well as vital viewability. Pre-stressing columns imparts additional load bearing capacity to them, thus allowing them to be made slimmer in size and permitting larger spacing between them but even then, their size can create problems.

To have columns with even more load bearing strength, so that their diameter could be further reduced, a new technique has been conceived. This technique results in the production of what is known as spun concrete. The process of making columns of spun concrete is roughly as follows: A steel mould in the shape of the column is made, in 2 halves. The reinforcement cage for the column is also made in 2 parts, one part is placed in each half of the mould, anchored to fixing devices, which are a part of the mould, and pre-tensioned. High strength concrete, up to M-100, is then poured into the mould halves. The halves are then bolted together and placed in a centrifuge.

The mould, with the concrete in it, is then spun for approximately 10 minutes, at 600 rpm. After that, the concrete is left to set, for between 12 to 16 hours, depending on various factors, such as strength required, column size, ambient conditions, etc. The mould is then removed and the column cured, then transported to the construction site. This process produces a very dense, high diameter of only 70cm, capable of taking loads up to 15%, have enabled production of 28 metre high columns, having a diameter of only 70cm, capable of taking loads up to 360 tons, by the use of spun concrete.