What Is Wire Mesh In Construction?

What Is Wire Mesh In Construction
Welded wire mesh Construction material A building worker is spraying on welded wire mesh Welded wire mesh, or welded wire fabric, or “weldmesh” is an electric fusion joined grid consisting of a series of parallel longitudinal wires with accurate spacing welded to cross wires at the required spacing.

What is wire mesh used for?

Wire mesh, which is also referred to as wire cloth or wire fabric, is an extremely versatile product that has thousands of different applications throughout the world. What makes wire mesh such an adaptable product is that is can be produced in a countless number of specifications.

  • Depending upon manufacturing capabilities, there are almost endless combinations of opening sizes and diameter wires that can be produced, either in a woven or welded construction.
  • Wire mesh is commonly used in industrial applications when separation or filtration is needed; it is also popular for use in commercial applications, like insect screening or animal fencing,

More widespread applications for wire mesh include: various types of security mesh, like window, machine and stairwell panel guards, fireplace screen, bird screen, gutter guards, ventilation and RFI shielding, More recently, wire mesh has emerged into the architectural field and the art scene,

Edward J. Darby & Son, Inc. prides itself on maintaining one of the most complete and extensive wire mesh inventories in the United States. Darby weaves, welds and stocks thousands of different wire mesh specifications including: woven and welded wire mesh, space (clear opening) wire cloth, standard or market grade, milling grade, and bolting grade.

In our 160 plus years of an industry leader, Edward J. Darby & Son, Inc. has supplied wire mesh to a broad range of industries and fields including: agricultural, automotive, biometrics, building & construction products, chemical, coal, electronic, food, glass, heat treating, insulation, machining, mining, oil and oil refining, plastics, pharmaceuticals, rubber, textile and tobacco.

What is wire meshing?

A great variety of shapes and applications – “Wire mesh” is a generic term. It refers to two- or three-dimensional lattices made from two or more metallic wires which are linked to one another by different processes such as welding, weaving, netting, or knitting.

What is wire mesh concrete?

Wire Mesh – Using wire mesh is a common method to reinforce poured concrete. The wire mesh makes a square grid pattern which is laid down before the concrete gets poured. The wire mesh is usually one layer of a two-dimensional grid that runs along the length and width of the poured concrete, but not the height.

What are the types of wire mesh?

What Weave Types are Available? – For standard woven Wire Mesh products, there are three main weave types to choose from: Plain, Lock Crimp and Intercrimp. What Is Wire Mesh In Construction Plain Wire Mesh is a traditional weave formed with straight warp wires and fill wires assembled in a simple over, under weave. The resulting product will exhibit a simple appearance with a relatively smooth surface. Plain weaves are often utilized in Wire Mesh items with a higher mesh count. It is likely that many of the wire cloth items you encounter in daily life will exhibit a Plain weave. What Is Wire Mesh In Construction Lock Crimp Wire Mesh also features straight wires assembled in a classic over, under configuration. However, this Mesh is characterized by a pinched, or locked, section of wire at each intersection. As the wires in one direction are woven above or below perpendicular wires, they are mechanically formed into secure “bumps” and “reverse bumps.” The locked wires create additional rigidity and security to prevent shifting or separating. What Is Wire Mesh In Construction Intercrimp Wire Mesh is made with wires that have been crimped in a zig zag fashion. When it is woven into a Mesh, there will be several crimps between each wire intersection. This texture creates a heightened grip between the crossing wires, therefore adding rigidity. In addition to helping the wires stay in place, these crimps are also beneficial for adding a unique visual interest. What Is Wire Mesh In Construction Intercrimp Wire Mesh as stairway railing Infill Panels

Where do we put wire mesh?

How Wire Mesh is Made Wire mesh sheet is a highly versatile product used for a wide variety of applications, from safety fencing, concrete reinforcement, light fixtures, to air filtration. can be made of many different metals – such as carbon steel or stainless steel – with a range of gauges and hole sizes.

How strong is wire mesh?

Stainless Steel Mesh Properties That Make it Strong – If you’re pondering the question, “how strong is stainless steel mesh?” here are some of its main properties:

Tear and puncture-resistant. Tensile strength between 850-900 pascals (efficiently prevents knife cutting and bullet shooting). There is resistance to severe circumstances, such as high/low temperatures (1472-2102°F) and high pressures, acids, and alkaline solutions. Highly corrosion-resistant and durable due to a 16% or higher percentage of chromium.

How is wire mesh measured?

MESH, MESH COUNT – The terms, “mesh” and “mesh count”, are often used interchangeably and represent one of the most important concepts in the industry. Both “mesh” and “mesh count” refer to the number of openings per linear inch – a critical component when specifying wire mesh. 4 x 4 MESH (.047″ Dia. Wire) 8 x 8 MESH (.028″ Dia. Wire) 20 x 20 MESH (.016″ Dia. Wire)

What is the difference between fiber mesh and wire mesh?

Advantages of Fiber Mesh Concrete –

Fiber mesh concrete is quicker and easier to work with. Fewer things can go wrong on-site when using fiber mesh concrete. Fiber mesh concrete requires adequate mixing time and energy to disperse the fibers properly. Synthetic fibers are corrosion resistant, while wire mesh concrete isn’t. Fiber mesh concrete is often cheaper than wire mesh concrete. The maintenance cost involved in warehousing decreases since the need for construction joints decreases or is eliminated. Compared to wire mesh concrete, it requires less space on-site and fewer deliveries, freeing up precious space and decreasing traffic.

Is wire mesh better than fiber?

The use of welded wire mesh in residential slabs has been on the decline for the last ten years as more contractors switch to synthetic-fiber-reinforced concrete. Synthetic fibers — which are often called Fibermesh, a well-known brand — have been marketed as a substitute for wire mesh in residential slabs.

  1. Most contractors are eager to avoid the hassle of wrestling with wire mesh, and prefer the easier option of ordering synthetic fibers from their ready-mix supplier.
  2. Jon Hanson is the vice president and estimator at Walker Construction, a concrete contractor in Stowe, Vt.
  3. We used to buy bundles and bundles of rolls of wire mesh, but we don’t do that anymore,” says Hanson.

“Now we use Fibermesh in just about all our slabs, unless it is a structural slab with a rebar mat.” Wire Mesh versus Fibers Although often seen as a substitute for wire mesh, synthetic fibers, at least at manufacturers’ recommended dosages, don’t perform the same function.

  • Properly placed wire mesh helps hold together a hardened slab, even if the soil settles slightly.
  • Unlike most synthetic fibers, wire mesh also controls drying shrinkage cracking — the type of cracking which can occur during a period of several weeks after the pour.
  • At typical dosages, the benefits of synthetic fibers occur only during the first few hours after the concrete is placed; after that time, they provide no real benefits.

Many studies have verified that synthetic fibers, unlike wire mesh, reduce plastic shrinkage cracking. Plastic shrinkage cracking occurs as the concrete makes the transition from liquid to a hardened slab. “Synthetic fibers help with avoiding plastic shrinkage cracks, but they don’t do much after the concrete hardens, in terms of providing a lot of strength for the slab later on,” admits Hal Payne, marketing services manager at Synthetic Industries, the manufacturer of Fibermesh.

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These bundles of fibrillated polypropylene fibers open up as the concrete is mixed, forming a more tenacious bond with the cement paste than monofilament fibers.

Plastic shrinkage cracking occurs only in weather conditions that encourage premature drying of the concrete surface. Although it is definitely a concern on a hot, dry, windy day, there is probably no danger of plastic shrinkage cracking when concrete is poured in cool, cloudy, windless conditions.

The reason that synthetic fibers have been successfully marketed as a substitute for wire mesh is that most nonstructural residential concrete slabs don’t need much reinforcement. Barring unusual soil conditions, if a residential slab is being placed on a well-compacted subbase, wire mesh — or, for that matter, synthetic fibers — can be safely omitted.

Depending on whether you want to control either plastic shrinkage cracking or drying shrinkage cracking, either synthetic fibers or wire mesh may be used. And if a residential slab actually needs reinforcement — either because it is partially unsupported or because it is load-bearing — then what you need is rebar, not wire mesh or synthetic fibers.

Hairy slabs? Some concrete contractors worry that fiber-reinforced concrete will produce a difficult-to-finish, hairy slab. “When synthetic fibers first came on to the market, we had these real long, real thick fibers,” says Payne. “Finishers didn’t like them, because it was hard to get the fibers mixed in and the concrete was hard to finish.

Since then the whole industry has changed. We now use a mix of fiber lengths and diameters, and the product gets mixed in easier.” Hanson, who has installed a lot of fiber-reinforced concrete, hasn’t had any finishing problems. “The power trowels go right over it, and lay the fibers down,” says Hanson.

“Many of the fibers will pop up later, but ultraviolet light burns them off, as long as they are exposed to daylight. After a year you don’t see them anymore.” Fiber Options Polypropylene is the most commonly used synthetic fiber, but other types of fiber, including nylon and polyolefin, are also available.

#use of fibremesh/wire mesh in building construction

Polypropylene fibers come in two different formats: fibrillated and monofilament. Fibrillated fibers have been deformed and shredded to form a net-like mesh that engages more tightly with cement paste than monofilament fibers. The main disadvantage with fibrillated fibers is their tendency to protrude from a slab.

Contractors who don’t want to wait for protruding fibers to wear off can burn them off with a torch, or specify monofilament polypropylene. Although monofilament fibers are less tenacious, they are less likely to stick up than fibrillated polypropylene. Another alternative is to specify nylon fibers, which also lay down better than fibrillated polypropylene.

Permeability, Although some synthetic fiber manufacturers have claimed that fibers make concrete less permeable, there is no evidence that this is true, at least at common dosage levels. “A few years ago, we claimed, along with other companies, that the use of synthetic fibers reduced the permeability of concrete,” says Fibermesh’s Payne.

  1. We have changed that claim.
  2. Fibers really don’t affect permeability.” Neal Berke, principal scientist at Grace Construction Products, a manufacturer of polypropylene fibers, agrees.
  3. In good quality concrete, fibers have no effect on permeability,” he says.
  4. To reduce the permeability, you’d be better off adding a water reducer and lowering the water-to-cement ratio.” What’s the best dosage? The recommended dosages provided by synthetic fiber manufacturers are not necessarily the optimal dosages for fiber concrete.

Most ready-mix suppliers charge an extra $7 or $8 per cubic yard to add 1 1/2 pounds of polypropylene fibers to their concrete, amounting to an upcharge of about 10%. This dosage level has been chosen by the fiber manufacturers to make synthetic fiber’s price competitive with wire mesh.

  1. Fiber concrete is a wonderful technology with many good uses, at the right dosage,” says Parviz Soroushian, professor of civil and environmental engineering at Michigan State University.
  2. But the manufacturers’ recommended dosages are not really sufficient to improve the hardened concrete properties.

At 0.1% by volume, which is equivalent to the typical manufacturers’ recommendations of 1 1/2 pounds per cubic yard, the benefits are marginal in hardened concrete. You need about 3 pounds of fiber per cubic yard. Once you double the dosage, you have much to gain — improvements in impact resistance, toughness, and control of drying shrinkage cracking.” Bob Cruso, president of Nycon, a manufacturer of synthetic fibers, doesn’t dispute Soroushian’s points.

We would love to be able to promote higher dosage levels, and we do for some applications,” says Cruso. “But we have to look at what we can offer at a price that is somewhat equal to welded wire mesh, because that’s what we are competing against. That’s unfortunate, but that’s the way it is.” Contractors interested in achieving the best possible performance from synthetic fibers should consider the option of doubling the normal fiber dosage recommended by the fiber manufacturers.

Before adjusting the dosage, though, be sure to consult with your ready-mix supplier and the fiber manufacturer’s technical experts, since higher fiber dosages may require less aggregate and more cement paste in the concrete mix. Fiber Manufacturers In addition to Fibermesh (Synthetic Industries; 800/635-2308; www.fiber-mesh.com ), several other manufacturers make polypropylene fibers, including Columbian Fibersource (800/821-4391; www.fibersource.org ), Forta (800/245-0306; www.fortacorp.com ), and Grace Construction Products (877/423-6491; www.graceconstruction.com ).

What is the difference between wire mesh and rebar?

The Differences Between Wire Mesh Panels and Rebar – When choosing a material for your facility, it helps to know the value of the leading options. Two of the most popular construction materials are rebar and wire mesh panels, To help guide you regarding the differences between these two options, we’ll address the subject and highlight which product is best suited for your applications.

What is wire mesh? Wire mesh is manufactured from cold-reduced, deformed steel and is laid out in a series of square panels. When used in concrete projects, the mesh panels have ridges that help form the attachment to the concrete structure. The wire mesh can add significant strength to the concrete and ensure optimal flexibility for a range of architectural applications.

What is rebar? Rebar is also made from steel but is generally laid out in larger squares than you would ordinarily find in wire mesh panels. Rebar is often used when cracking occurs in a concrete structure, as a reinforcement material. Which offers the best value for my project? Wire mesh is more cost-effective One of the foremost considerations in most structural projects is the total cost for the material.

Wire mesh panels are more cost-effective. Because mesh arrives at the site in a roll, there are fewer labor expenditures to consider during installation. Rebar can be stronger but might be considered overkill for projects While rebar is often stronger than wire mesh, you might find that the level of strength provided by rebar is overkill for most projects.

Heavy-duty wire mesh can offer the required level of durability while limiting your costs considerably. Wire mesh can offer greater flexibility Wire mesh is designed to offer high levels of flexibility when combined with concrete for structural projects.

Contractors often find that the smaller squares of the mesh and the thinner steel material can be used in a great range of applications compared with bulkier rebar. Working with a qualified manufacturer of wire mesh panels can help your organization reduce its mesh costs and ensure you find the right product for your applications.

Our experts at California Wire Products are committed to helping each client achieve full value when sourcing wire mesh material and our service is designed for both convenience and optimal levels of communication. To discover more about the many benefits that wire mesh can bring to your upcoming projects, please call our team at California Wire Products today.

Why is wire mesh used in plaster?

Quality Products of Sri Maruthi Wire Netting Company – உழவனின் காதலன் Plaster mesh is most often used to form the skeletal layers of plaster and putty based constructs. Maruthi provides international grade plaster mesh for excellent protection in conditions with variances of temperature and humidity, and under considerable mechanical stress. As reinforcing material, plaster mesh is used for building internal and external decoration, especially in plastering work. It protects the plaster layer surface from cracking and increases the mechanical strength of the plaster layer. What Is Wire Mesh In Construction

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Does all concrete need wire mesh?

Reinforcement for Floors on Ground – Is reinforcement necessary? NO With uniform support and short joint spacing. YES When long joint spacing is required or when joints are unacceptable in floor use. Although short joint spacings alleviate the need for reinforcement, wire mesh will allow for increased distance between joints if correctly placed in the upper portion of the slab, at least two inches below the surface.

In these slabs with longer joint spacings, the purpose of wire mesh is to hold random intermediate cracks tight. Plastic fibers should not be expected to replace wire mesh in a slab on ground. However, although not affecting joint spacing, plastic fibers are used to reduce plastic shrinkage cracking. Plastic shrinkage cracks are those that occur immediately following concrete placement, before the concrete has hardened.

Plastic fibers are commonly dosed at 0.1 percent by volume for slabs on grade; this is equivalent to 1.5 pounds per cubic yard. Although polypropylene fibers are among the most common for controlling plastic shrinkage cracking, there are many types of fibers in addition to polypropylene, including other plastic materials, such as nylon.

What are the 3 types of wires?

Name the three types of wires used in household circuits. Out of these three, which wire is used as a safety measure especially for those appliances that have a metallic body. State the colour of insulation used for this wire. How does this wire ensure the safety of the user? Answer Verified Hint: The three wires used in the electric power line to our house have a different purpose.

  1. We use a colour code for insulating these wires to minimize confusion.
  2. Because of these wires, there is a chance of getting shocked by appliances so as a safety measure we use one of these wires for electrical earthing.
  3. By knowing what this process is we can answer how that wire ensures the safety of the user.

Complete answer: The three types of wires used in household circuits are Earth wire, Live wire, and Neutral wire. What Is Wire Mesh In Construction Out of these Earth wire is used as a safety measure especially for those appliances that have a metallic body. The colour of insulation used for this wire is Green.This wire ensures the safety of the user as the metallic body linked to the earth wire maintains its potential at that of the earth’s zero potential.

  1. The user does not receive any form of electric shock as a result of the leakage.
  2. If the live wire comes into contact with the metallic body of the appliance, the current flows directly to the ground via the earth wire.
  3. Because it does not require our bodies to transfer the current, we do not experience an electric shock.

In this way, the electric appliance is protected from harm caused by excessive current, and we are also protected from electric shock. Note: Live wire is a positive wire generally red in colour. The neutral wire is a negative wire generally black in colour.

The electric power that we receive in our houses is by the main supply, commonly called mains. The meter board distributes these cables to various electric appliances throughout the house. : Name the three types of wires used in household circuits. Out of these three, which wire is used as a safety measure especially for those appliances that have a metallic body.

State the colour of insulation used for this wire. How does this wire ensure the safety of the user?

What are the 4 types of wires in use?

2. Wire Lettering – The letters THHN, THWN, THW and XHHN represent the main insulation types of individual wires. These letters depict the following NEC requirements:,

  • T – Thermoplastic insulation
  • H – Heat resistance
  • HH – High heat resistance (up to 194°F)
  • W – Suitable for wet locations
  • N – Nylon coating, resistant to damage by oil or gas
  • X – Synthetic polymer that is flame-resistant

Can you use wire mesh in concrete slab?

Concrete Wire Mesh Helps Minimize Concrete Slab Cracking and Settling – In fact, the best way to minimize the chance of cracking and settling is to use fiber mesh and WWM in the same slab. Like any structural product, WWM won’t do its job unless it’s installed correctly. It’s crucial to ensure that welded wire mesh be placed on chairs of the proper height. Otherwise, the mesh won’t effectively hold the slab together. | Photos: courtesy IBACOS Wire that’s not placed on chairs will not be effective, but in the rush to get jobs done, some crews eliminate the chairs and roll the wire directly out over the plastic sheeting that covers the dirt. Making sure all of this gets done right can be a training and quality assurance challenge for the builder, and avoiding that challenge may be one reason why so many opt for synthetic fiber for these applications. But in soils that make settling likely, this type of oversight really needs to be a priority.

How much wire mesh do I need for concrete?

The Steel Mesh calculator – When wondering if you need mesh in your concrete slab, or figuring out how much mesh you need, firstly, you need to calculate the area of your concrete slab. To do this simply multiply the length of the slab by the width. Here is the formula: Length x Width = Slab Area (m2) For example: What Is Wire Mesh In Construction For measuring a more complex concrete slab design, try to break the total area into separate rectangles or squares. Calculate each one and then add them all together to find your total area, for example: What Is Wire Mesh In Construction Now that you have your area calculation, you need to divide the area by 12.5. This will give you the number of steel mesh sheets required to reinforce your concrete slab. Here is the formula: Slab Area (m2) ÷ 12.5 = Total number of 6m x 2.4m sheets For example: What Is Wire Mesh In Construction

What is wire mesh called?

Basics of Wire Mesh – Wire mesh is fabricated by the intertwining, weaving, or welding of wires of various thicknesses to create proportionally equal parallel rows and intersecting columns. Also known as wire fabric, wire cloth, or hardware mesh, the production of wire mesh involves the weaving of wire on industrial looms, leaving square or rectangular gaps between the wires. What Is Wire Mesh In Construction There are a limitless number of shapes, sizes, and configurations of wire mesh made from an assortment of highly durable and resilient materials whose major function is to separate, screen, structure, and shield various applications and processes. The types of wire include galvanized steel, stainless steel, aluminum, steel, and copper alloy wire.

Is wire mesh expensive?

The approximate cost of wire mesh is $20-25 per square foot.

Does mesh rust?

Understand Why Architectural Mesh Is Stainless Steel? – Architectural wire mesh is a series of stainless steel wires that become interlocked after a stringent weaving process. As these wires are made from 316 stainless steel, architectural mesh, by itself, will not rust.

That said, contaminants, such as dissimilar alloys and corrosive airborne particles, can compromise the mesh surface and raise the chances of rusting.W.S. Tyler has been helping architects weave their vision into reality for 20 years and wants you to feel confident in your decision to incorporate architectural wire mesh into your architectural design process.

To help, we wrote the article below to provide insight into why we choose to weave our architectural wire mesh from stainless steel wires:

Why Architectural Mesh Is Predominantly Stainless Steel

Do you need wire mesh?

Reinforcement for Floors on Ground – Is reinforcement necessary? NO With uniform support and short joint spacing. YES When long joint spacing is required or when joints are unacceptable in floor use. Although short joint spacings alleviate the need for reinforcement, wire mesh will allow for increased distance between joints if correctly placed in the upper portion of the slab, at least two inches below the surface.

In these slabs with longer joint spacings, the purpose of wire mesh is to hold random intermediate cracks tight. Plastic fibers should not be expected to replace wire mesh in a slab on ground. However, although not affecting joint spacing, plastic fibers are used to reduce plastic shrinkage cracking. Plastic shrinkage cracks are those that occur immediately following concrete placement, before the concrete has hardened.

Plastic fibers are commonly dosed at 0.1 percent by volume for slabs on grade; this is equivalent to 1.5 pounds per cubic yard. Although polypropylene fibers are among the most common for controlling plastic shrinkage cracking, there are many types of fibers in addition to polypropylene, including other plastic materials, such as nylon.

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Should I use rebar or mesh?

· Support: – Considering the support constraint, rebar is undoubtedly stronger than wire mesh. Several constructors consider rebar for domestic jobs. For thicker driveways and locations that involve greater traffic, rebar is always a good option to consider.

Is wire mesh better than fiber?

The use of welded wire mesh in residential slabs has been on the decline for the last ten years as more contractors switch to synthetic-fiber-reinforced concrete. Synthetic fibers — which are often called Fibermesh, a well-known brand — have been marketed as a substitute for wire mesh in residential slabs.

Most contractors are eager to avoid the hassle of wrestling with wire mesh, and prefer the easier option of ordering synthetic fibers from their ready-mix supplier. Jon Hanson is the vice president and estimator at Walker Construction, a concrete contractor in Stowe, Vt. “We used to buy bundles and bundles of rolls of wire mesh, but we don’t do that anymore,” says Hanson.

“Now we use Fibermesh in just about all our slabs, unless it is a structural slab with a rebar mat.” Wire Mesh versus Fibers Although often seen as a substitute for wire mesh, synthetic fibers, at least at manufacturers’ recommended dosages, don’t perform the same function.

Properly placed wire mesh helps hold together a hardened slab, even if the soil settles slightly. Unlike most synthetic fibers, wire mesh also controls drying shrinkage cracking — the type of cracking which can occur during a period of several weeks after the pour. At typical dosages, the benefits of synthetic fibers occur only during the first few hours after the concrete is placed; after that time, they provide no real benefits.

Many studies have verified that synthetic fibers, unlike wire mesh, reduce plastic shrinkage cracking. Plastic shrinkage cracking occurs as the concrete makes the transition from liquid to a hardened slab. “Synthetic fibers help with avoiding plastic shrinkage cracks, but they don’t do much after the concrete hardens, in terms of providing a lot of strength for the slab later on,” admits Hal Payne, marketing services manager at Synthetic Industries, the manufacturer of Fibermesh.

These bundles of fibrillated polypropylene fibers open up as the concrete is mixed, forming a more tenacious bond with the cement paste than monofilament fibers.

Plastic shrinkage cracking occurs only in weather conditions that encourage premature drying of the concrete surface. Although it is definitely a concern on a hot, dry, windy day, there is probably no danger of plastic shrinkage cracking when concrete is poured in cool, cloudy, windless conditions.

The reason that synthetic fibers have been successfully marketed as a substitute for wire mesh is that most nonstructural residential concrete slabs don’t need much reinforcement. Barring unusual soil conditions, if a residential slab is being placed on a well-compacted subbase, wire mesh — or, for that matter, synthetic fibers — can be safely omitted.

Depending on whether you want to control either plastic shrinkage cracking or drying shrinkage cracking, either synthetic fibers or wire mesh may be used. And if a residential slab actually needs reinforcement — either because it is partially unsupported or because it is load-bearing — then what you need is rebar, not wire mesh or synthetic fibers.

Hairy slabs? Some concrete contractors worry that fiber-reinforced concrete will produce a difficult-to-finish, hairy slab. “When synthetic fibers first came on to the market, we had these real long, real thick fibers,” says Payne. “Finishers didn’t like them, because it was hard to get the fibers mixed in and the concrete was hard to finish.

Since then the whole industry has changed. We now use a mix of fiber lengths and diameters, and the product gets mixed in easier.” Hanson, who has installed a lot of fiber-reinforced concrete, hasn’t had any finishing problems. “The power trowels go right over it, and lay the fibers down,” says Hanson.

  1. Many of the fibers will pop up later, but ultraviolet light burns them off, as long as they are exposed to daylight.
  2. After a year you don’t see them anymore.” Fiber Options Polypropylene is the most commonly used synthetic fiber, but other types of fiber, including nylon and polyolefin, are also available.

Polypropylene fibers come in two different formats: fibrillated and monofilament. Fibrillated fibers have been deformed and shredded to form a net-like mesh that engages more tightly with cement paste than monofilament fibers. The main disadvantage with fibrillated fibers is their tendency to protrude from a slab.

  1. Contractors who don’t want to wait for protruding fibers to wear off can burn them off with a torch, or specify monofilament polypropylene.
  2. Although monofilament fibers are less tenacious, they are less likely to stick up than fibrillated polypropylene.
  3. Another alternative is to specify nylon fibers, which also lay down better than fibrillated polypropylene.

Permeability, Although some synthetic fiber manufacturers have claimed that fibers make concrete less permeable, there is no evidence that this is true, at least at common dosage levels. “A few years ago, we claimed, along with other companies, that the use of synthetic fibers reduced the permeability of concrete,” says Fibermesh’s Payne.

We have changed that claim. Fibers really don’t affect permeability.” Neal Berke, principal scientist at Grace Construction Products, a manufacturer of polypropylene fibers, agrees. “In good quality concrete, fibers have no effect on permeability,” he says. “To reduce the permeability, you’d be better off adding a water reducer and lowering the water-to-cement ratio.” What’s the best dosage? The recommended dosages provided by synthetic fiber manufacturers are not necessarily the optimal dosages for fiber concrete.

Most ready-mix suppliers charge an extra $7 or $8 per cubic yard to add 1 1/2 pounds of polypropylene fibers to their concrete, amounting to an upcharge of about 10%. This dosage level has been chosen by the fiber manufacturers to make synthetic fiber’s price competitive with wire mesh.

  • Fiber concrete is a wonderful technology with many good uses, at the right dosage,” says Parviz Soroushian, professor of civil and environmental engineering at Michigan State University.
  • But the manufacturers’ recommended dosages are not really sufficient to improve the hardened concrete properties.

At 0.1% by volume, which is equivalent to the typical manufacturers’ recommendations of 1 1/2 pounds per cubic yard, the benefits are marginal in hardened concrete. You need about 3 pounds of fiber per cubic yard. Once you double the dosage, you have much to gain — improvements in impact resistance, toughness, and control of drying shrinkage cracking.” Bob Cruso, president of Nycon, a manufacturer of synthetic fibers, doesn’t dispute Soroushian’s points.

  • We would love to be able to promote higher dosage levels, and we do for some applications,” says Cruso.
  • But we have to look at what we can offer at a price that is somewhat equal to welded wire mesh, because that’s what we are competing against.
  • That’s unfortunate, but that’s the way it is.” Contractors interested in achieving the best possible performance from synthetic fibers should consider the option of doubling the normal fiber dosage recommended by the fiber manufacturers.

Before adjusting the dosage, though, be sure to consult with your ready-mix supplier and the fiber manufacturer’s technical experts, since higher fiber dosages may require less aggregate and more cement paste in the concrete mix. Fiber Manufacturers In addition to Fibermesh (Synthetic Industries; 800/635-2308; www.fiber-mesh.com ), several other manufacturers make polypropylene fibers, including Columbian Fibersource (800/821-4391; www.fibersource.org ), Forta (800/245-0306; www.fortacorp.com ), and Grace Construction Products (877/423-6491; www.graceconstruction.com ).