I would like some feedback on any experience of using Fibermesh Products as substitute for secondary reinforcement in pavements and slabs-on-grade. I'm working in Saudi Arabia where the climate is very harsh on concrete and rebar corrosion is very widespread. The temperatures here are high during the Summer months and pouring and curing pavements is troublesome.

I am very happy to meet you here. I know fibermesh quite well and use it 60.000 bags per year in Turkey in precast, industrial slabs, topping and screed application. Also there is exist Microban-B to stop microbiological growing in the concrete.

Before using any fibers steel one (NOVOCON) or syntetic one (FIBERMESH) you should check what you want to obtain.....

And learn correctly the limits (what it can be or not)of fiber reinforced concrete.

I will happy to provide more specific information if you have any curtain problem or recent project.

Specific information is send docs, sample, tips, design, dosage, etc.

bye

merbas
Great to hear that you have used Fibermesh in Turkey. I want to use the Fibermesh in sidewalk pavements and driveways to houses in order to eliminate using galvanized steel mesh. Have you experienced any problem in finishing slabs on-grade? The specific gravity of the Fibermesh is only 0.91 which means that it will tend to float to the top of wet concrete. I would like to hear more on what you consider are the limitations to using Fibermesh concrete
Regards

MPHenry

gravity of fibermesh is 0,9kg/lt. according to ASTM 1116-C fiber reinforced concrete specification, if any concrete has 0,1% fibers by volume we called it fiber concrete. Therefore for 1 M3 concrete volume we should add minimum 1lt fibers and this means 0,9kg/m3 is minimum dosage. Fibermesh provide in soluable bags in 0,9kg/bag.

on the other hand, the lenght of the fibers is important. usally chosen same lenght of max aggragate diameter, ie. if your max. aggragate dia 19mm, you should use 19mm (3/4") fibers.

mike

if your slab "ground suppoted slab" this means load well carried by earth, wiremesh is useless. because of placing correctly (50mm from top) even you use spacers, it will be impossible.

what it is main idea of fibers?
1. stoping settlement
2. homogeniusly distribution of aggregate.

plastic concrete while like soup, agg. will settle to bottom and blading water appears on the slab. this water quickly evaporate and slab will shrinage. Fibers reduce shrinage settlement cracks.

uniform distribution of aggregates provide surface hardining and abbrassion resistance.

in pathways and driveways, it will work properly, without problem, but I advice also a cure product.

On the other hand, as beauty and functionaly I offer you exposed aggragate surfaces. Exposed Aggregate Surface (EAS) is visiable aggragate technic and ideal for low traffic ways.

it can be coloured concrete or colour aggragate solution.

bye

murat

Murat
Thank you for your advise. I will be trying out the fibermesh in a repair job we are carrying out on a boat ramp. The surface of the existing ramp is deteriorated and we are going to apply a new 10cm. surface screed using fibermesh to control cracking and shrinkage. This will be a very good test case for the material as it will be exposed to the harshest environment available in the Middle East.
Regards
Mike

mike
where do you buy FIBERMESH?
murat

Murat
I will be purchasing the FIBERMESH from

The Building Products Co. Ltd (SCIC)
PO Box 4
Riyadh 11411
KSA

Tel: +966(1)4027287
Fax: +966(1)4025565

Regards

Mike

WHat will Fibermesh do the modulus of rupture in a slab (MOR) ?
I am designing a 6" slab with steel reinforcement. If the MOR is higher then I don't need as much steel. An ACI book states that the MOR for a plain 3,000 PSI slab is 493. How much will Fibermesh increase that ?
Thanks,
Bill

Merbas
I have not poured the concrete screed using Fibermesh yet. We are holding back on the job until November when the temperatures are lower. Our temperatures at the moment are in the high 40's with humidity running at 80-90%. Not very pleasant weather. Will you keep you informed on developments.
Mike

Bill

The use of fibers is primarily to control cracking in the concrete and to improve the durability of the finished structure. Any increase in the MoR is incidental as the distribution of the fibers is so random as not to be used with confidence in a design guide. The partial factor of safety on the material component would be prohibitively high.

regards

Ginger

Merbas
We are now ready to pour concrete using Fibermesh as outlined in previous correspondence. I would like to know exactly how one goes about mixing in the Fibermesh fibers into the concrete mix. Do you add them at the batching plant? Do you add them on site prior to the pour by mixing them into the mix using the delivery truck?
A friend of mine said it is very difficult to get an even distribution of fibers throughout the concrete mix, is this true? His experience was that the fibers tend to go into a ball and do not distribute. Also he felt that the more you mixed the worse the problem got. What is your experience?
I would appreciate a response as soon as possible as I would like to pass on your experience to our Project Engineer in the field.
Regards
Mike

mike,

I use to fibermesh as non structural reinforcement since 1997. I do not know why your friend said that it would not mix well. Fibermesh fibers deliveried in a special packing ambalage which called fas-pack where soluable in the water.

You can add fibers into concrete either batching plant or at the site in the truck mixer, results will be same.

just mixing the fibers in five minutes high speed turn is enough for well mixing, without opening bag.

just jump to bags into truck mixer without openning dosage must be 0,9kg/m3.

Fibermesh will increase the slump a bit, but never change of maniabilty (workablity) of concrete. If it is necessery just add some fulidifier, no water please.

my experience for well mixing, if the truck mixer capacity is 8m3, please fill the truck only 7m3.

Other way is filling mixer 8m3 and mixing in five minutes in a ramp. Back wheels must be higher then front wheels. In this position there is not concrete presure in the neckle of the mixer drum so that blades mix concrete from top to bottom easily.

If you mention the brand name of truck mixer such as volvo, samsung, etc. I can help more.

My previous experience for samsung truck mixer from lafarge.

Fibemesh made polypropilen, therefore not consumed any water from the concrete.But I can not say same things for nylon or PE fibers.

I have satified results from fibermesh my all jobs.

I always thing that "I wish to sell fibermesh, because it is fonsional and realy works in the concrete."

Although I'm not an expert in the field of concrete, I can provide you with some feedback from the perspective of a consumer.  I've read your discussion and based on my experience would highly recommend against using Fibermesh, particularly in a desert environment.  I live in a hot, dry location with highly alkaline soil.  The slab under my house is Fibermesh reinforced and cracking badly after less than ten years.  Both the builder and the makers of Fibermesh are involved in a lawsuit.

Fibermeshing it?
 
Aside from several niceties about Fibermesh, such as
shrinkage issues, surface wear/tear, permeability, ease
of working with, non-corrosive properties, cost consi-
derations, 'fad' factor (we always want somethin 'new')
etc, etc, we need to look at the down-to-earth issues
of what we expect and need from the finished product
called concrete: strength, hardness, resistance to va-
rious influences (even such as dynamic forces), bend,
etc. And we cannot but conclude that fibers
- may not bind well with cement 'water-based' paste thus
  making concrete effectively 'porous' and weaker (and
  adding more of them will make matters worse) - to pro-
  ve this point (and even if they did bind with cement!)
  do you remember that rebars have ridges? and that wire
  mesh should be welded at cross points? do you know why?
  So? How do you expect to emulate that with lose fibers?
- being plastic and hence elastic even stretchable do
  not and cannot reinforce anything sturdy such as conc-
  rete (remember: they do not have 'hooks' or 'knots' at
  their ends, either to hold anything together). This is
  why the 'visitor's' house has its foundation falling
  apart. Period. Fibermesh does not perform as a stru-
  ctural asset which in plain English means it takes
  away structural properties of concrete. And concrete
  without its important structural properties (which it
  has to have even in a garden path) is not concrete a-
  nymore but a weakened crumbly mixture of sand, gravel,  
  cement granules/dust, fibers and whatever else we add.
  It still holds out when not exposed to much of stress
  but 'in spite of the fibers', not because of them doing
  anything much for it it seems.

Some may hold on to it trying to find justification upon
justification as is common with humans (same as tobacco
companies keep on staying alive with all their reasoning
which with some people works). But for how long? So I de-
finitely put in a word of caution.
                                      - engineer -
                                 

viveutvivas, Have you looked into Caprolan RC nylon fibers??
They do have the hooks at their ends.  Not only that, but the nylon actually absorbs the water to become one with the matrix.  Try it and you will like it.  I guarantee no problems.

Does anyone know of or have experience with water vapor transmission problems with a slab-on-grade concrete foundation using fibermesh?  Our home is four years old and we have already replaced all of the flooring.

polypropylene naturally weak at clorine enviroment in high temperature.

Therefore in desert conditions before pouring concrete you shoul use PE geotextiles under the bottom of concrete structure.

Murat ERBAS / Electrical Engineer M.B.A.
SPI Engineering & Foreign Trade Ltd.
Acibadem AYPIM POB 242 Istanbul 81020 Turkey spiengtr@ttnet.net.tr
Tel : +90.216.342.76.07

I note that a previous comment mentioned Caprolan nylon fibres. Nylon is considerably stronger than poly about twice as stong I believe, and does not float . When pumping concrete you can use nylon microfibres to stengthen the mix.