VACUUM DEWATERED FLOORING

SUBMITTED BYRAM TOSNIWAL

UNDER THE GUIDANCE OFProf. SHASHANK U VANAKUDARI

A seminar on,

JAIN COLLEGE OF ENGINEERING, BELAGAVI

CONTENTS• Introduction to VDF • Definition, benefits & History of VDF• Need & Overview of VDF• Process & Equipments• Advantages & Disadvantages of VDF• Steps Involved in VDF & Precaution• Applications • New Techniques for dewatering • Conclusion & References.

FUNCTIONAL REQUIREMENT OF INDUSTRIAL FLOORS

• Trouble free movement of Man, Machines & Materials.• Hygienic/anti-bacterial.• Highly cleanable.• Wear (abrasion) resistant.• Chemical Resistant.• Resistance from Impact and Static Loading.• Ease of Maintenance.• Anti-slip/anti-stain properties• Flammability and Fire Safety.• Scratch/scuff resistance

VDF : Definition

A Flooring Technique to achieve •High Strength,•Longer Life,•Better Finish•Faster Work.•High abrasion & heavy traffic movement

VDF : Benefits

• Concrete with better workability than what is normally possible.

• Improvement in wear resistance, compressive strength, less shrinkage and minimum water permeability.

• Reduction of water content in the concrete by 15-25%.• Tendency of shrinkage and subsequent cracking is greatly

reduced. • Concrete of high initial slump can be used while pouring

HISTORY OF VDF

• It was originally invented by Tremix AB, Sweden many years ago.• 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.• This process was introduced in India by Aquarius Technologies in

1987.

Need of VDF

• 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.

• It renders an economical, time-efficient compaction technique to concrete that can be placed on a medium to high workability.

CONDITION OF CONCRETE BEFORE & AFTER VDF

SCHEMATIC DRAWING SHOWING VDF

COMPARISION BETWEEN STRENGTH OF VDF & ORDINARY CONCRETE

EQUIPMENTS

•Double beam screed vibrator•Vacuum pump with Hose•Suction mat•Power float•Power trowel

DOUBLE BEAM SCREED VIBRATOR

• Light weight• Electrically driven. • Overall length – 4200mm• Width – 410mm• Height – 125 mm• Total weight – 128.5 kg

VACUUM PUMP WITH HOSE

• 7.5 H.P electric motor mounted trolley• Capable of 35 sqm in one operation.• Length – 2200 mm• Width - 660mm • Height – 880mm• Weight – 320kg • Pump capacity- 110 m/Hr

SUCTION MAT• Large single PVC sheet • Under surface Nylon cloth to act as very fine filter. • Top mat is provided with junction box and short hose. • The mat size may be 7.5 5m or as of the panel size

POWER FLOAT

• Surface grinding equipment• It grinds the surface to make it wear resistance• Remove surface modulation prior to final finishing• Overall height – 980mm• Floating speed – 120RPM• Equipment weight – 140kg

POWER TROWEL

• Surface finishing equipment,• Polishes the surface after floating operation.• Overall height – 980 mm• Trowelling speed – 120 RPM• Equipment weight – 145 kg

STEPS INVOLVED IN VDF

• Prepare sound sub-base• Form work over the base• Concreting & Vibration• Double beam screed vibration• Laying of mat & vacuum suction• Power troweling & finishing

Filling of Boulder materials in the flooring area. Compaction of the boulder materials.

Filling of Girt in the boulder material. Fixing of Thiyas

Laying of PCC ( 1:3:6) Laying of Bitumen over PCC

Laying of PVC Sheet & Thermocal Sheets for Thermal Insulations.

Bar Bending work.

Vaccum Dewatering Proccess

Polishing the surface using power trowel

Completed Cold Storage project at KIADB of KAPPEC, Bijapur.

ADVANTAGES OF VDF

• Early setting and high strength. • An ideal water cement ration can be achieved • Increase in compressive strength of concrete by 40-70%. • The surface hardness of the slab increases by 130%. • Water absorption is reduced enormously. • Minimum dusts. • Level floor, high flatness accuracy.

ADVANTAGES OF VDF

• Minimized crack formation, Shrinkage reduced by 50%. • Improved wear resistance. • Elimination or minimization of overtime. • High and early strength, minimize damage to newly cast

floors. • Void-free& Denser concrete.• Elimination of curling• Reduced maintenance cost• Earlier utilization of floors

DISADVANTAGE OF VDF METHOD

• High initial cost.• Need trained labor.• Need specific equipment.• Need power consumption.• The porosity of the concrete allows water, oil and grease to

seep through, consequently weakening the concrete.

DISADVANTAGE OF VDF METHOD

• Joints are a necessity for concrete floors leading to joint breakage as well as seepage of contaminants.

• Concrete floors generate dust due to abrasive movement of vehicles.

• Cleanability becomes a problem due to the presence of imperfections, surface roughness and porosity.

• The best-laid floor (Tremix) can have undulations of above 5mm

APPLICATIONS

• Industrials floor sheds like cold storages, etc.• Workshops, • Railway goods, platforms, • Godowns, warehouses etc. • Canals• Hydro power plants • Bridges ports and Harbor • Airports runways/ Hangers • Cooling Towers

NEW TECHNIQUES FOR DEWATERING

• Permeable and absorbing formworks• Perforated PVC pipes incased in cotton cloth

CONCLUSION

• 200 sqm – 250 sqm of concrete flooring can be done in 8-10 hrs.• Good quality of floors and pavements can be obtained.• The compressive Strength can be increased by 25-45%.• Durability of the floor can be increased.• 15-25% of water can be extracted out.

References

• Construction of a rigid pavement with vacuum dewatering Indian concrete journal volume 71 – page 13

• Dahl G., (1975), "Vacuum concrete", CBI Reports, 7: 75, Part 1, 10 pp. (Swedish Cement and Concrete Research Inst.,).

• Neville A. M., (2011), Properties of Concrete, 5th Edition, Longman Sc and Tech Publishers.

• Vacuum dewatering system/tremix method from Aquarius Technologies Private Limited,india www.aquariustech.net

• Vacuum dewatering procedures Publication #C750290 Copyright © 1975, The Aberdeen Group

• Tanksali Consultants, Bijapur.

Thank You,..

Any Queries ?