Can you permanently fix cracks in concrete structures?
Theodoros Yfantidis
Exports Director | Building Peace of Mind in the Construction Sector
On the 24th of August 2016, a massive earthquake hit Amatrice, Italy. Hundreds of people died and half of this small town was destroyed. The same happens anywhere in the world, after a major earthquake takes place. Life seems to stop. But life, fortunatetly or unfortunately, goes on. And life wihout a shelter, that is a house, cannot really be. So what can a person in Amatrice, or anywhere in the world, do when she has a #concrete #structure full of cracks, but she desperately needs to repair it in order to be able to live in?
She will defintely need to use some materials that will restore the concrete structure back to a monolithic piece (this means that her structure needs to be something like one big stone). These materials need to have high mechanical strength, strong bonding, high sealing ability and a viscosity that will allow them to be injected into the cracks and fill every single gap.
One of the solutions can be the #injection of #epoxy #resins. Most probably, she will find different type of products, with different viscosities that will allow her to fill any crack in any width.
So after finding a highly qualified application crew, the procedure roughly goes as follows:
- Any existing plaster/ render in the area of the crack should be removed and the surface of the concrete must be cleaned thoroughly.
- The crack is sealed with an epoxy putty. At the same time some special nozzles are positioned and fixed along the entire length of the crack.
- Once the epoxy putty has hardened, the resin injection procedure can be carried out. The two components of the epoxy resin are mixed and then put in an injection pot. Then, by applying pressure, the material can be injected into the cracks.
- The resin outlet tube is placed in the first nozzle. If the crack is horizontal, the procedure starts from one end, if it is vertical, from the lowest nozzle.
- The resin is forced into the nozzle until it starts to come out of the next nozzle, or until it is impossible to apply more pressure.
- The first nozzle is sealed with a special cap and then the resin is forced into the immediately adjacent nozzle until it starts to come out of the next one, and so on.
- The procedure mentioned above is carried out on all the nozzles. The next day the nozzle projections are removed, by being broken off, and any pre-existing plaster/ render may be restored.
All comments are welcome. #BuildingPeaceOfMind
Owner, ANAGHA ENGINEERS
8 年That totally depends on type of cracks, ie due to dynamic loading or some other reasons. Various flexible high strength materials are available to repair moving cracks
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8 年How to treat dynamic crack?
Civil Engineer
8 年I read article veary carefully I found it very interesting. In example given here, I'm preatty sure that the main problem is bearing capacity of concrete structure, not concrete cracks itself and I doubt that this could be solve with the injection of the epoxy resin. Epoxy resin could be good potential solution to stop water penetration into the concrete but after repair of conrete structure from the structural point.
Civil-Structural Engineer M.Sc
8 年Are we aiming to the same target in each case by filling the cracks with epoxy/resin? I suppose that we aren’t. Are we always aiming to make the cracked member monolithic in order to behave as such when subjected to some type of loading (how much realistic is to try to do such thing when concrete, as a material, is by default cracked)? The main purpose of filling the cracks is for sealing against moisture/water and consequently against corrosion, isn’t it? If the width of cracks is large in vertical members or in beams, probably we have to do some other type of intervention. The (negative) consequence as concerns the stability/integrity of each structural member of the bearing structure, when cracks are not so large of course, is mostly the reduction of its stiffness and not so much about its strength (when a member is subjected to compression, cracks tend to close, while in tension the reinforcement is called to do the work). In other words, sealing is the main purpose when filling the cracks, isn't it..?
Sterling Contracting inc.
8 年I have also done many hundreds of feet of crack injection, curb, walls, floor, in coolers/freezers outside inside, and delaminations, some delaminations that had been under standing water for some time, ive had only a couple delaminations that have failed and not because of moisture. I think that moisture is very rarely a problem.