Welded Wire Mesh - Reinforcing India

Saturday, 22 December 2012

Weldmesh Reinforcement - Introduction

Welded Wire Fabric (WWF), commonly Welded Mesh, is a prefabricated reinforcement consisting of parallel series of wires having a very high yield (Fe-480). The wires are cold drawn or cold-rolled, welded together in square or rectangular grids. Each wire intersection is electrically resistant – welded continuously by an automatic welding machine.

Welded Wire Mesh is bonded to concrete by a positive mechanical anchorage at each intersection.

Benefits of Welded Wire Fabric:

I. Controlled Manufacture

Weldmesh is manufactured from hard drawn steel wire and thus has a tensile strength not less than 580 N/mm²while the tar steel used in traditional construction maybe as low as 250 N/mm²

II. Proper Distribution of Steel

Weldmesh provides equal distribution of steel reinforcement within the concrete slabs, affecting the strength. The number of small diameter wires spread across the cross section help in arranging the concrete slabs according to the specification.

III. Better Anchorage/Bond

Since the HYSD bars are tied with barbed wire at the intersection, they tend to be loose and shifty whereas a weldmesh sheet is strong in its intersection and rarely falls apart.

IV. Better Crack Resistance

o Research into crack width and the width prediction formulae adopted by the building cost show the maximum widths are propotional to the distance from the surface to the closest reinforcement i.e. to bar spacing and concrete cover and the inter reinforcement spacing.

o Weldmesh is much superior in restricting the crack width to acceptable limits in concrete slabs because of smaller diameter of wire used, closer and with uniform spacing.

o Thinner wire with closer spacing is efficient in ensuring more homogenous 2-way stress distribution throughout the concrete volume thereby controlling crack propagation as well as the crack width.

V. Easily Handled and Placed

Being welded automatically at joints, little labor is required for placing and fixing. When properly supported it remains fixated in its position during concretization.

VI. Adaptable For Forming And Shaping

Weldmesh possesses the right degree of ductility to allow it to be bent, shaped or fashioned readily on the job, yet it is sufficiently rigid to maintain its shape after bending.

VII. Higher Characteristic Strength

Use of Weldmesh with Fe-480 grade results in savings in steel area or steel weight required to the tune of 15% vis-à-vis HYSD bars of Fe-415 grade and to the tune of 47.92% vis-a-visplain mild steel bars of Fe-250 grade.

VIII. Better Corrosion Strength

Welded Wire Mesh, with thinner wires at closer spacing and more concrete cover, has relatively smaller cracks restricting the ingress of moisture and air to steel.

Buiilding Codes: For Welded Wire Mesh in Reinforcement

IS:4948-1974 (Re-affirmed 1992)

This standard covers Welded Wire Mesh for the general use, such as fencing, window grill crates and other such uses for the concrete reinforcement. The chemical composition of the steel wire to be used for the manufacture of Welded Wire Mesh shall conform to S:226 - - 1969

IS:1556-1982 (Re-affirmed 1989)

This standard covers the requirement for hard-drawn Steel fabric consisting
of Hard - drawn steel wire with cross-wires electrically welded to them for use as a concrete reinforcement.
The wires used in the manufacture of weldmesh shall be hard-drawn steel wire conforming in all respect, to the requirements of IS:432 (Part II) - 1982 and suitable for welding.

IS:432 (Part II) - 1982

Specification for Mild steel & Medium Tensile Steel Bars & Hard drawn steel wire for concrete reinforcement.

SP:16 (DESIGN AIDS For IS:456-1978)

Presents tables and charts for steel grade fy 480 N/mm2 also in all grades of concrete.

SP:34-1987
"Hand Book on Concrete Reinforcement and Detailing" has elaborated the arrangements to be made for provision of welded wire mesh reinforcement in various types of structural members with Welded Wire Mesh as reinforcement.

Limit State Design can be used by the designers of concrete structural members with Weldmesh as reinforcement.

Design Aids for Reinforcement
The use of Medium tensile steel (Plain Bars) and Hard drawn Steel Wire Fabric has been permitted as concrete reinforcement vide Section 1.2 of the above standard. The specifications are given in IS:1566 and IS:432 respectively.

IRC:58-1988
Indian Road Congress recommends the use of Welded Wire Mesh in the reinforced pavements.

http://www.4shared.com/office/ESv83KSf/IRC-58.html

CPWD Schedule of Rates - 1997

The Welded Wire Mesh as the reinforcement material exists in the above "Schedule of Rates" under steel Reinforcement section.

ASTM & CSA

The American Society for Testing & Materials has established specification for the Welded Plain and the deformed fabric.

Few Important Publications:

(a) "Structural Welded Wire Fabric, Manual of Standard Practice"

(b) "Structural Welded Wire Fabric Detailing Manual"

Friday, 21 December 2012

In Making 3: Filming Weldmesh

In Making 2: Filming Weldmesh

In Making 1: Filming Weldmesh

CONCERTINA COIL: Manufacturing Details

MM Industries is the only manufacturer & service provider of Punched tape Concertina Coil in Chhattisgarh according to Defense specification no. : IND/ENGG/PRO/1245-B.

It is made of CR carbon steel and Spring Steel Core Wire coated with Corrission Preventive fluid and is a revolutionary concept for high security fencing as it cannot be intruded and gives total protection.

So it is very suitable for high security zone like Naxal affected areas, Strategic locations, Dams, Airports, Thermal power plants, Mines, Industries and Prisons etc. It is quite economical, durable and secured.


Copyright: http://www.mmweldmesh.com

Welded Wire Mesh: Manufacturing Details

We manufacture Welded Wire Mesh ranging from 1mm to 12mm, using MS, GI and SS wire. Surrounded by wire mesh today, the product is used in variety of fields. The kind of flexibility in specifications we provide, has allowed us to serve Common Fencing, Poultry mesh and Tree guards. We have put weld mesh to strategic use too, constructing safer roads. Over the years, MM Industries has spread its distribution network through large traders spread across India.
Reinforcement is one of the emerging and most significant areas where Welded Wire Mesh becomes essential. Weld mesh is the most effective replacement for the traditional tar steel in reinforcement, used all over the world for many years now.

REINFORCEMENT USES:

RCC Roads	Flooring	RCC Pipe	Fireproofing Walls
Pavements	Runways	Canal Lining	Water Tank