VDF Method Statement is discuss in this post. It is a technique of reducing the water cement ratio on top surface of concrete slab. This improves the performance of concrete in work-ability and gives high strength. This reduces the small holes forms on the concrete surface. It makes the concrete slab to set sooner and harder. And by performing this the setting time of concrete improves and it attains more strength early. This increase the  compressive strength of slab.

VDF Method Statement

The surface preparation is the first works begins with cleaning concreting area without dust on surfaces. And grade slab concrete pours over PCC with required reinforcements embedded inside it. And levels and finish neatly.

This grade slab is the base slab for vdf flooring. The laid grad slab cures to attain  its minimum compressive strength for required time period. After this the entire area divides and marks into alternative panels as per design requirements. These panels frames and fix using ISMC ( steel c – channels ) of required depth and as per slope requirements. The reinforcement works carries inside these panels as per design with proper cover. And concreting proceeds with approved design mix grade of concrete.

Screed vibrator

This laid concrete levels properly and uniformly with the help of screed vibrator. It is a less weight double beam element assembled with ms tubes fixed with a motor above it. And drives electrically with help of manpower.

Filter pads

After leveling the filter pads places above the leveled concrete surface. It lays above leveled concrete surface to prevent the washing away of cement along with water. These are rolled mats consisting of multiple layer of net filters in it. And it comes in a size of 1.2 in width and 3.8 meters in length. These filter pads lays at the center of the panel leaving space at margins along four sides. This space provides for placing suction mats over filter pads.

Suction mat & Vacuum Pump

The suction mats places above filter pads for suction of moisture and excess water in slab. This suction mats connects to a vacuum pump to observe and collect all the excess water and moisture. These mats comes in a size of 4 m x 4 m minimum and can be made as per design panels. It is a large mat made of a single pvc sheet. At center of this mat a junction box fixes with a provision of hose pipes. This pipe connects to a vacuum pump.

After finishing the process of sucking out all wet moisture content, the slab allows to dry for certain time period. And the troweling process starts. This troweling starts with mechanical power floaters with disks and continuing with blades attached to powerful motors.

Mechanical Power Floaters

These rotating disks and blades runs above the dry concrete surface forming a uniform smooth surface emerges at top layer of concrete panels.

After these finishing with mechanical power floaters, the C-channels removes. And the alternate bay concrete adjacent to finished panel concretes and finishing completes. These vdf floor allows to cure for required time period.

Diamond cutter for Grove cutting

To prevent the formation of cracks above flooring and preventing cracks passing to other panels, these panels separates. It is done by cutting them in to specified groves using diamond cutter with steel concrete cutting blades within 48 hours.

To carryout the grove cutting, the connection joints between two panels identifies and marks above it. This performs to identify the exact line joint in-between two panels. After this the grove cutting executes. This size of groves varies depends considering the design, loads and usages. For normal floors a grove size of 5 mm in width and 25 mm in depth executes. And for heavy duty floors like runways, hangars, warehouses, it is of 10 mm width and 30 mm depth.

Sealants

The groves forms in these panels seals with sealing agents and sealants. The polysulphide sealants uses most for filling the groves. In larger grove sizes and running meter of grove is more, excess amount of chemicals consumes.

Backer rods

To prevent the excess consumption of chemical sealants backer rods uses. It is a white color elastic material made of foam. These backer rods embeds inside groves at certain depth. And above it the sealants fills uniformly and finishes neatly. These backer rods and sealants are elastic in nature, it allows the free movements of concrete expansion and contraction. It executes to prevent formation of cracks.