VDF
flooring work for civil structure that is both time
efficient and medium to high workability process
to create a facility that is safe, healthy and
comfortable concrete flooring to be done by used of vacuum dewatering concrete flooring (VDF) technology.
This process is a means to efficiently remove excess water from newly placed, compacted
and leveled concrete surfaces. Vacuum treatment of concrete has been refined to specially
address concreting of large exposed surfaces in hot weather conditions. Vacuum dewatering greatly
improves the abrasion and impact resistance of the concrete surface. The vacuum dewatering results
in coarse aggregate in the fresh mix being drawn to the top surface a further contributing
factor in achieving wear-resistant concrete surfaces the surface of vacuum treated concrete is free of
pitting, an important consideration for abrasion resistance and the possible exposure to a
continuous flow of liquid over the member. Technologies applied in concrete flooring will improve concrete
flooring physical behavior.
This method used like concrete flooring in warehouse, concrete road,
parking area, production area in industrial buildings.Nowadays this vacuum dewatering technique for
concrete flooring is excessively using by various contractors & builders in order to get good
quality & to achieve speed in construction of concrete floors. This paper provides a review on a new way
of concrete flooring by the used of vacuum dewatering concrete technique/remix method in the
area of concrete flooring in civil structure with its advantages & dis-advantages of VDF system.
 |
| VDF at parking |
A high quality concrete floor or pavement requires not only to be level, but it should also have high wear resistance, high compressive strength, reduced shrinkage and minimum water permeability.The Vacuum Dewatered (VD) Flooring method is a system for laying high quality concrete floors with superior cost-effectiveness. The key to the use of this method is the dewatering of concrete by vacuum process. Surplus water from the concrete is removed immediately, after placing and vibration, reducing the water-cement ratio to an optimum level.
1) Adopting the VD flooring method facilitates use of concrete with better workability than what is normally possible.
2) A lowered water to cement ratio due to vacuum dewatering leads to improvement in each of the properties of concrete like wear resistance, compressive strength, less shrinkage and minimum water permeability.
 |
| VDF application |
4)
By lowering the water-cement ratio, the tendency of shrinkage and subsequent
cracking is greatly reduced.
5) Since the water-cement ratio is lowered through vacuum dewatering, concrete of high initial slump can be used while pouring.
History
The vacuum dewatering process, patented in the United States, nearly half a century ago, has attracted increased interest in recent years after several Scandinavian firms simplified the equipment enough to make it practical for almost any builder Vacuum dewatering is used widely throughout Europe today, and in Sweden the method is used for 40 to 50 percent of all concrete floors. Basically,the process improves strength, durability, and other properties of concrete by reducing the water-cement ratio immediately after the mix is placed, usually in floors and other flatwork.Tremix or vacuum dewatering flooring is popularly known in India, is actually Vacuum dewatering process of concrete. It was originally invented by Tremix AB, Sweden many years ago. This process was introduced in India by Aquarius Technologies in 1987. In 1991 to start production of Vacuum System in India. It became so popular in India that almost everybody related to concrete flooring industry, may be manufacturers / contractors / consultants started calling this process by the name of its inventor.
Needs of VDF
1) The mixing water added to a concrete mix exceeds the amount of water required to fully hydrate the cement constituent.
2) The additional water functions as a lubrication medium to allow mixing, placing, leveling and consolidation. In conventional concreting practice, an important challenge is the prevention or limiting of evaporation of mixing water out of the freshly placed concrete.
3) The uncontrolled removal of water from the concrete matrix can result in adverse effects such as plastic shrinkage cracking. Excessive bleeding of concrete can negatively interfere with surface characteristics such as resistance to wear. Thus the durability and service life of the flooring element is in question. Concreting in areas exposed to the elements, specifically in hot and windy conditions poses even higher demands in order to produce quality, durable concrete.
Advantages
1)
Reduction in W/C ratio leads to early setting and high strength.
2) This system removes the excess water after pouring of the concrete & thus an ideal water cement ration can be achieved
3) Increase in compressive strength of concrete by 40-70%.
4) The surface hardness of the slab increases by 130%.
5) Water absorption is reduced enormously.
6) Minimum dusts.
7) Level floor, high flatness accuracy.
8) Minimized crack formation, Shrinkage reduced by 50%.
9) Improved wear resistance.
10) Elimination or minimization of overtime.
11) High and early strength, minimize damage to newly cast floors.
12) Void-free& Denser concrete.
Disadvantages
1) High initial cost.
2) Need trained labor for the vacuum dewatering process.
3) Need specific equipment for vacuum dewatering like vacuum pump.
4) Need power consumption
during dewatering process
0 Comments
For more Information Please Comment