Resurf® FAQ

1) What is a polymer concrete?

Resin, Hardener (catalyst) and filler (aggregate/aggregate blend)

2) What is a composite?

Polymer concrete with fiber

3) What is a rapid set mortar?

Speeded-up Portland cement concrete, calcium sulfate, magnesium poly-phosphate, or other inorganic compounds and small aggregates which are mixed with water.

4) What is a polymer modified concrete?

Portland cement concrete or rapid set mortar that uses latex water (or "sticky" water) LMC: latex modified concrete

5) Why are Resurf® II and Resurf® LR polyester not epoxy based?

The reactivity of polyester based systems is very easily controlled for year-round return to traffic in 2 hours or less, regardless of either extreme of ambient temperature. Adjustment of handling and cured physical properties are formulated by PCI.

6) Do polyester resins systems tolerate water well?

No, everything needs to be as dry as practical.

7) Can epoxies be used in cool-cold weather?

No, not if you are in any kind of a hurry to return traffic.

8) Do epoxy systems tolerate water well?

Yes, much better than polyesters and can be formulated for under water applications: Resurf® VO-21. See: Sealing Joints in Wet Culverts

9) Why is VO-21 epoxy based?

Vertical and overhead systems are more easily handled, do not have heat-up problems, plus these are often in very wet areas.

10) Do you recommend sawing?

No! Sawing never follows fracture lines and does much more harm than good. Keep repairs as small as practical. Resurf® II and Resurf® LR feather to zero. Sawed faces transmit cure, thermal, and mechanical stresses down a plane and make failure much more likely. If a product needs or recommends sawing, don’t use it!

11) Are Resurf® II and Resurf® LR general purpose polymer concretes self leveling?

No! They should be tamped aggressively to consolidate well and then screeded to grade. Good tamping and good consolidation squeezes out most air (oxygen slows the reaction significantly). This makes the cure reaction much, much faster and shortens the return to service time several fold.

12) Can I work repairs slightly wetter than label directions?

Yes (see scribed mark on resin measuring pail), but only slightly wetter and only for very shallow (one inch or less) or very narrow or small, featheredged repairs. Good, quick mixing and good consolidation make repairs much easier to work and appear wetter. NEVER work large and deep repairs any wetter than MARKS on the measuring pails! Very deep repairs can be a little under the line on the resin measuring pail. Aggressive tamping will still force a small amount of resin to the surface. This also significantly strengthens the bond to the concrete.

13) What is wrong with using more (much more) than recommended amount of Resurf® resin in Resurf® II or Resurf® LR polymer concrete?

Physical properties were tested at resin content on bag directions and scribed pails. Wetter mixes (much wetter) will have significantly higher cure shrinkage and significantly higher thermal contraction (cold weather) and expansion. These two stresses on the Portland Cement Concrete add together in cold weather when the concrete is also shrinking and highest modulus (most brittle). This math model (when total stresses is greater than a physical value of the concrete) will result in failure. The above is extremely detrimental in large and deep repairs! On banked slabs, wet repairs are much more apt to self level and sag. See numerous videos on our website. 

14) Why is good tamping and consolidation very important? 

It pushes out air (oxygen) that would significantly slow the cure reaction. This is very important. Well compacted repairs can be returned to service much sooner. Good tamping also pushes into crevices and pores to improve contact area and bond strength. Good tamping aids in screeding and finishing to grade. 

15) Does PCI have a general purpose, self-leveling polymer concrete for very wet or underwater repairs?

Yes. Resurf® CRE with very fine aggregate and Resurf® IIE (uses Resurf® II aggregate blend) for larger repairs. These systems use the same epoxy resin and hardener as Resurf® VO-21. Resurf® CRE epoxy resin and hardener also make an excellent bonding agent for bonding fresh concrete to old concrete. We will gladly write job-specific procedures for these or any of our products.

16) Do you generally recommend sandblasting?

Yes, where practical. Sandblasting is a great tool to clean and evaluate spalled concrete.

17) Do you ever recommend pressure washing or slurry blasting?

Yes, for areas where sand or dust is a problem. We will gladly help you write procedures based on which Resurf® product is called for.

18) How do I estimate repair volume and choose batch size?

When broken concrete is removed to “sound” concrete, estimate average depth, width, and length of spall in inches. V=D x W x L = cubic inches. There are 1728 cubic inches in a cubic foot (12” x 12” x 12”). We package Resurf® II and Resurf® LR in 0.5 Cu Ft bags, so 2 bags equals a cubic foot. So, volume in cubic inches of repair ÷ 1728 = Cu Ft. The Cu Ft x 2 = bags estimated.

19) What is the shelf life and what is the guaranteed shelf life of PCI’s polyester and hardener and epoxy systems?

When Resurf® II and Resurf® LR (polyester) resin and catalyst (hardener) are stored reasonably cool and dark (completely blocked from sunlight), PCI guarantees a minimum shelf life of 12 months. All of our epoxy based systems: Resurf® VO-21, Resurf® CRE, Resurf® IIE, and Resurf® Bonding Agent have a shelf life well over 10 years. It is recommended to protect them from hard freezing during storage.

20) How can Resurf® Resin (polyester) be tested for suitable use?

If Resurf® Resin (polyester) is still low viscosity (sloshes in drum or pail), it is OK for use. To test resin and catalyst reactivity, mix a capful of catalyst in 3 oz. paper cup of resin. Set in shade. Gel time should be from 10 to about 30 minutes. See Reactivity Test Video. Ideally, these tests should be performed prior to going to the field. Call us, we will help you. 334-682-4296

21) What is accelerator and when should I use it?

Accelerator (see directions on bottle) is used to significantly shorten the return to service time. It is NOT a hardener, so it can and should be WELL mixed into Resurf® Resin minutes or months before catalyzing and using the resin. Accelerator is usually not used if ambient temperature is 70°F or above. One capful (or less) per 5 gallons Resurf® Resin is plenty fast down to about 60°F or below and 2 capfuls (or less) per 5 gallons resin for temperatures significantly under 60°F. Cold weather emergency repairs (especially at night) benefit greatly from accelerator use and VERY good compaction for quicker return to service. See Reactivity Test video.

22) Is there a minimum or maximum repair depth?

Not really. Resurf® II and Resurf® LR are always recommended to be featheredged to zero. For extremely deep repairs, 1 to 2 Ft or more, we recommend measuring resin a little under the normal mark on the scribed resin pail (1 or 2 gallons). The repair can be done in layers but good tamping/consolidation is essential with each batch. We do not recommend a mechanical vibrator.

23) Can we mix Resurf® II or Resurf® LR with a drill mixer (whip)?

Absolutely Not!

24) Can we mix with a drum or concrete mixer?

Absolutely Not!

25) Can we mix with a mortar mixer?

Yes, usually up to 6 bags at a time and several batches BUT please call to discuss. This can be a disaster!

26) Can we mix in a contractor wheelbarrow with sturdy garden or small mortar hoe?

Please do!

27) How do you recommend cleaning tools?

Scrape clean after each batch. Break clean after curing overnight and when coolest in the morning. Use 1-4# hammers on wheelbarrows, hoes, shovels, trowels, etc. to break off cured polymer concrete. Carefully knock/break out polyethylene pails. Bristle paint brushes are disposable but several spalls can be primed at one time. Primer can be still liquid or gelled for a few hours with same results.

28) Are there any solvents that are recommended for tool cleanup?

No. Methylene chloride will clean a mortar mixer disaster but call us first. Actually, call us before you use the mortar mixer.

29) How far ahead can we prime?

A few hours for polyester systems.

30) What should we do if an unexpected rain shower is imminent?

Cover everything to keep dry. Cover resin, aggregate blends, and all tools. If spalls or joints are ready to prime, then do. If primer is on dry concrete before rain hits, the water is less of a problem and easier to remove. A shop vac is a good tool here after the shower passes by. After removing as much water as practical, the surface can be re-primed and polymer concrete placed.

31) What thickness and widths of Resurf® Joint Forming and Sealing Systems (RJF & SS) are available?

These systems come in 6.5 Ft planks generally available from 1/4” to 3” thickness and 3” to 9” wide in one inch increments. Any custom thickness is available. These are often trimmed or carved so scrap pieces can be saved for later projects. RJF&SS revolutionizes joint forming and sealing in one simple step.

32) Can Resurf® II, Resurf® LR, or Resurf® IIE be applied as a “broadcast buildup” or “broom and sprinkle/seed”?

Yes, this can be an easy, quick and very effective way to repair large and large numbers of fire spalls and other shallow spalls or increase skid numbers. Call us and we will help you write a project specific procedure.

33) What is carbonated concrete and what problem does it cause?

Carbon dioxide reacts with water vapor to yield carbonic acid. This weak and dilute acid reacts over a period of time with the basic nature of the Portland cement concrete to leave a soft carbonated film. Surface carbonated concrete prohibits good bonds with any product for any purpose. This film, along with road oil and other contaminants, must be physically (not chemically) removed for good strong bonds.

34) Are the aggregate bags waterproof?

No, they are poly-lined paper bags. They are somewhat water resistant but definitely NOT waterproof. Keep Dry!

35) Will resin drum bungs or resin faucets leak rain water and contaminate resin?

Yes, tilt, cover the drum top, or store inside.

36) What do you recommend for form release?

A rich solution or dispersion of silicone caulk in gasoline applied one or more hours previous to using polymer concrete is clean and very   effective. Using white silicone caulk makes it easier to see the coverage.

37) Can Portland cement concrete spalls and failures be repaired with asphalt? 

Only for emergency and life threatening repairs, even then they may leave the hole and result in a hole and a bump. Many years ago, 2 excellent reports by Mississippi State University and later by Auburn University described problems with anaerobic bacteria eating on the asphalt secreting many different carboxylic acids, hydrogen sulfide, and numerous thiols. All these and several other acid species destroy the basic Portland cement concrete. Evidence of this attack can often be observed on the underside of bridge spans as cracks and spalls. Stalactites of calcium carbonate and other calcium and sodium salts are often present. See MSU Report Summary and AU Report. 

38) Do you offer a general job planning checklist?

Yes, you can download a general checklist PDF on the All Resurf® Products page

39) Why is your RJF & SS packaged in a plastic bag and box?

For polyester resin systems, it is very important for the sawed-open cells to stay dry. Opened cells will take in water and are difficult to dry. This is not critical when epoxy based systems are used.

40) Are training videos available for all Resurf® products?

Yes, see RESURF® II and also, onsite and classroom training is available and encouraged.

41) Is a hands-on, experienced technical person available 24/7 to answer specific questions or prevent/solve problems?

Yes! Call 334-412-244