How To Repair Etched Concrete

It is possible to repair acid damaged concrete.  Titus Restoration Services, Inc. has performed repairs to acid damaged physical floors successfully as shown in the before and after pictures below.  In 2022 we polished 144,000 square feet of a convention center.  Within a calendar month there was an auto prove and acid was spilled on the finished polished concrete.  Battery acid was spilled on the concrete floor and tracked throughout one of the exhibit halls (approximately 36,000 sf).

How Repairing Acid Damaged Polished Physical is Performed

Polished concrete has become more popular in the terminal iii decades in retail and municipal buildings due to its low maintenance costs.  Due to its popularity and increased square footage installed throughout the world, acrid damage to polished concrete has get more prevalent.  A few building uses that have turned from carpet, vinyl tile (VCT) or other hard surface floor to polished physical include: grocery stores, schools,  liquor stores, big box lumber companies, wearable stores, hardware stores, car dealerships, industries requiring dust free and hands cleaned floors, nutrient warehouses, medical warehouses, and distribution centers, and  fifty-fifty general warehouses.

Buildings Nigh Exposed to Acid Damaged Concrete

The polished physical floors in some buildings are more susceptible to acid damage to their polished concrete floors than others.  Some of the most susceptible floors are liquor stores, grocery stores, and automotive repair shops – or anywhere an acidic liquid could be spilled.

• In a liquor store, an accidentally broken bottle of red wine can impairment a polished concrete floor.  Wine has balmy acidity and the red color makes the stain await worse. Since 2022 stain protection has been developed to protect confronting this hazard merely the product must be allowed to dwell on the floor.
• In a grocery store, any acidic item spilled on the polished concrete could etch the polished finish.  These include vinegar, pickle juice, wine, colas, etc. Hither again, stain protection is now bachelor for this potential hazard as the acids are mild.
• In an automotive store, the hazard is bombardment acid.  While the newest technology in polished concrete stain guards will protect against many oils, in that location is no current polished concrete protection for strong acids such as bombardment acid (sulfuric acid).  Chemically resistant coatings can protect concrete floors from hydrochloric (muriatic) acid or other potent acids.

Understanding  Acid Damaged Physical

Whether it be polished concrete or the concrete flooring of a warehouse, it is not possible to just follow the acid trails with a flooring grinder and properly restore the floor.  It is important to empathize both the characteristics of concrete and acid.  Concrete has a pH of 11 or higher and acids that are strong enough to damage it have a ph of 4 or lower. Upon contact, they are quite reactive but they seek equilibrium and soon they neutralize themselves. Based on this self-canceling reaction, it is more typical than not that the damage is located nearer the surface of the physical rather than deep inside the concrete.

The repair of acid damage to concrete should be left to an experienced professional person, especially when aesthetics are important.   It is very like shooting fish in a barrel to use too aggressive diamond tooling and does irreparable impairment to the aesthetics of the slab. The ability to skillfully blend is of import and requires experience, however is non always 100% possible.  The restoration professional has to know when to cease grinding deeper and incurring more than costs.

About Acid Damaged Concrete

The acid has eaten through the difficult-cap of the concrete and the floor must be restored to preclude further erosion and dusting.  Beneath is a more detailed explanation of the characteristics of a concrete slab along with some key points to consider when repairing acid damage on a physical floor:

1. 1. 1. When a concrete floor is poured, the physical finishers utilize trowels to make it polish.  In a large warehouse, the trowels they use are typically a heavy ride on blazon with a combustion engine and steel smoothing blades.
   1. 1. As the floor is troweled the finest particles come up to the top (this is chosen the concrete cream), then below the concrete foam is sand, and below the sand is pea gravel and larger aggregates.
   1. 1. As the concrete dries and moisture leaves the slab, capillaries of air are left in the concrete making it susceptible to moisture absorption.
   1. 1. Because the fine particles (concrete cream) take risen to the meridian of the slab, the top of the slab is more than dense and harder.  Typically, multiple trowel passes are fabricated during concrete placement to brand the surface very slick and hard.
         1. 1. Typically the concrete beneath the cream is a different color than the surface of the cream.
               • • Typically the foam will have a Mohs hardness of iv-6.
               • • Typically, once the foam is gone, the Mohs hardness will drop 1-2 points to a three-five.
               • Contractors who are experienced in concrete grinding, honing, and resurfacing will use dissimilar diamonds, multiple passes, and special reactive liquid silicate concrete hardening chemicals to restore the surface of the concrete to every bit close to the original Mohs hardness equally possible.
   1. 1. For decades physical warehouse floors have been chemically treated to prevent dusting.  This is a one-time treatment that reacts with the free lime in the concrete to harden it and preclude dusting.
   1. 1. Based on Titus' xv years of experience equally a concrete restoration specialist (and 49 years experience in physical coatings), this acrid has penetrated through this chemically hardened concrete layer and the damaged areas are softer and volition dust more easily.
   1. 1. This acid has damaged the cement paste, not the sand or aggregates.  Microscopically, acid etched physical would resemble a sponge as the acrid travels through the capillaries of the concrete and dissolves the cement paste.
   1. The restoration procedure will require diamond grinding deep plenty to remove the acid marks, which volition, in turn, remove the top layer of concrete that has been treated for anti-dusting and hardening.

How to Repair Acrid Damaged Physical

1. 1. Determine the starting grit of diamond to remove the acid impairment.  Titus does this with a variable speed moisture paw grinder or a three-headed countertop polisher and diamond pads called electroplates.
      1. We volition start with a fine grit and work our way to coarser grits to decide the proper starting grit.
      2. Titus lets the floor dry at each grit as a wet floor is very deceiving, it will hide whatsoever blemishes.
      3. Once the proper grit has been determined, we will apply all the chemicals and finish the test area.  This is a irksome process. Much time is spent waiting for the floor to dry. A heat gun or hair dryer will speed up this process.  Count on three to 4 hours minimum to determine the starting diamond.
   2. Once the starting grit has been determined, wet diamond- grinding the flooring to remove the damaged concrete begins.  Wet grinding is a very important condom issue to Titus. Information technology increases both personnel and building problems apropos silicosis.
   3. Nosotros proceed with multiple finer grit diamonds, decreasing the grit size with each pass, to eliminate visible scratches and keep the floor cleanable.
   4. We autoscrub the floor to remove the concrete slurry from the slab.
   5. Once the floor is clean and dry out, information technology is then time to chemically re-harden and dust-proof the physical floor.  It of import to proceed the chemical wet twenty minutes and to apply the chemical to rejection. .
   6. Finally, remove backlog chemical and re-autoscrub. The restoration is now complete.
      1. Burnishing the floor with a diamond impregnated pad is optional. Adding stainguard to the floor is optional.  It increases gloss and makes the floor more cleanable, only it will not protect against harsh acids.
      2. If oil spills are a business organization, please suggest your contractor.  Stain protection from oil is currently available.

In determination, Titus' goal is to restore the floor to as shut to its original state equally possible. Please annotation the following clarifications:

1. 1. From observing the surface, it is incommunicable to tell how deep the acid has penetrated the concrete.  It may non be possible to remove the lite color of the acrid marks completely. Nosotros accept included pictures of recent work – there is a very faint discoloration in some areas.
   2. Titus volition starting time the restoration process using the least invasive wet diamond grinding process every bit possible.
   3. The floor may incorporate discoloration after restoration.  This is considering:

• • • Until grinding begins, it is impossible to know the depth of acrid impairment.  This would vary based on many things, including the amount and concentration of acrid spilled in whatever given expanse.
  • • The depth of the foam and if the acid damage went through the foam.
    • The colour of the physical below the cream.

Titus will perform the restoration of an acid-damaged flooring with utmost care in gild to render to you a physical floor that is functional in terms of hardness and anti-dusting, and gratis of acid marks.

HP2 Certificate

Source: http://www.titusrestoration.com/blog/floor-restoration/repairing-acid-damaged-concrete/

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