A: Problem: When water evaporates from concrete the color of concrete bleaches out (becomes lighter). The water to cement ratio in concrete is what dictates color. Concrete patching compounds that conform to ASTM C 928 often have a low water/cement ratio <0,4. Most concrete walls have a water/cement ratio >0.5. Therefore they won’t match, with the patch being much darker.

Problem: If white Portland cement and gray Portland cement are mixed with sand, they will not be cohesive. White Portland demands more sand to cement than gray. Therefore, a packaged gray mixture and a package white mixture that are properly proportioned will mix and are cohesive.

Problem: Match patching requires that both the patch area and the patch material be similar in moisture content. Therefore, if the wall to be patched has dried out, then the patch must be matched dry.

Solution: Recrete 5 is manufactured in both gray and white and are properly proportioned, and can be mixed in any proportion.

Solution: Mix the gray and white in differing proportions, continuously increasing the amount of white. Add these proportioned mixes to the correct water ratio for patching and mix and allow the patches to dry or dry them in a micro-wave-oven. Mix the wall patch in the proportion that is closes to the color of the wall. The tie hole often has form oil in the void and should be de-grease. A bonding admixture such as Ad-Bond (J-40) improves bond, flexural and tensile strengths and improves workability.

A: Problem: Drilling into concrete is relatively slow, and it is a given that some of the cement laitence will adhere to the side-walls of the hole. Therefore, any hole should be mechanically brushed and vacuumed before inserting an epoxy for doweling. Solution: J-50 or J-51 require that a hole in concrete be surface prepared so that the greatest possible surface area is available for bonding. A 1/8” oversized power driven wire brush is ideal, along with vacuuming the grindings, way to prepare a dowel hole for either J-50 or J-51.

A: The carpet and tile mastic manufacturers made an agreement with EPA to remove all solvents from their carpet and resilient tile mastics. They agreed not to manufacture ¡§cut-back¡¨ mastics, which contained solvents. For this agreement, the carpet and resilient tile mastics manufacturers are exempt form the Clean Air Act. The solvents in the old cur-backs softened the acrylic or chlorinated-rubber curing and sealing compounds so that a good bond was achieved and the curing and sealing compound also restricted vapor transmission or served as a vapor barrier. These new mastics will not bond to any organic compound. Therefore, no membrane forming curing compounds, manufactured in the US today, that conform to ASTM C 309 and are compatible with the currently available carpet and resilient tile mastics.„h Solution: Use a silicate as the curing method, such as Sil-cure (J-13), and delete the need for conform to ASTM C 309. This method is effective if the application is indoors out of any wind.

A: In 6.6.1. in ASTM C 1315 requires that carpet and resilient tile mastics bond to curing and sealing compounds. This is impossible; since the mastics on the market today, are water based and will not bond to curing and sealing compounds. „h Solution: recommend that only area that will not receive carpet and tile be treated with a curing and sealing compound that complies with the other paragraphs of ASTM C 1315, Day-Chem Cure & Seal (J-23) complies with the other requirements of Class A.„h Solution: ASTM C 309 is a moisture retention specification. ASTM C 1315 incorporates: moisture retention, yellowing, chemical resistance and mastic compatibility.

A: Plastic shrinkage occurs when the rate of evaporation of the surface water in the concrete exceeds the available moisture in the concrete. Plastic shrinkage cracks are more common in periods of low humidity and hot weather.„h Solution: Use an evaporation reducer such as Sure-Film (J-74) right after striking off and straight-edging (bull-floating) of the concrete surface.„h Solution: Curing must commence as soon as the concrete is finished as long as there are no water puddles. Delaying curing can produce more defects than just plastic shrinkage cracking.

A: Checking is the result of accelerated drying in small modules at the concrete surface. It can and often is the result of over working the concrete surface. „h Solution: Outside concrete should not be steel trowelled, and an application of curing compound as soon as the concrete is finished will reduce the potential, but will not cure the problem if the surface were over worked. Use Rez-Cure (J-11-W).„h Solution: Checking is not a structural problem it is aesthetic.

A: Different construction materials: concrete, block and brick have highly variable surface densities. Therefore, the ability of a material to penetrate also varies.„X Solution: Use a siloxane J-26-WB or J-27-WB on porous surfaces and silanes J-29 and J-29-A on dense surfaces.

A: All dissipating resins are hydrophobic. They must be applied to a moist surface to spread out and form a membrane. If applied to a dry surface, they will penetrate and not produce a membrane.Solution: Day-Chem Rez-Cure J-11-W is a dissipating resin, and, if it is applied to a moist surface, and if concrete surface is in direct sun-light, the J-11-W will start breaking down in 30 days. Complete dissipation will take longer and the timing is weather dependent.

A: Silanes when applied to dry concrete produce a monomerization reaction, or they produce a plastic-like film just below the surface of the concrete. Silane was developed in Canada to prevent salting form deteriorating concrete pavements. The Canadians did not want this product to change the profile of the concrete surface (they didn’t want the highway to be slippery).Solution: Weather-worker S-40 (J-29) produces its water-repellent-film below the concrete surface so that the concrete will not be slippery.

A: The drying oils (linseed oil and tung oil) are natural product and have been in existence for hundreds of years. They also have been government subsidized, and they are by-product and cheap.„X Solution: Water repellents such as the Weatherworker S-40 (J-29) is a penetrating sealer that does not alter the surface profile (is not slippery) and will last for many years. DSC will give up to a 10 warranty on these products. Linseed oil produces a more slippery surface, will discolor and will last less than a year as a water repellent.

A: Water-proofers prevent any vapor or water transmission and must be capable of resisting hydro-static pressure. Damp-proofers prevent any vapor or water transmission, but are not able to resist hydro-static pressures. Water repellents must resist surface wetting.Solution: DAYTON-SUPERIOR CORPORATION has water repellents: J26-WB, J-27-WB, J-29 and J-29-A.

A: Split-faced-block are very porous.Solution: Use Weather-worker J-27-WB. J-27-WB has the largest molecule size and the highest solids content.

A: Problem: Bonding agents that are re-dispersible (re-emmisable) can produce delamination if the patch becomes wet, well after the application, and is followed by freezing and thawing (ACI 548-00).

Solution: Ad-Bond (J-40) is non-re-dispersible and can be used both inside and outside. Superior Concrete Bonder (J-41) is re-dispersible, and should only be used inside. Levelayer Bonding Agent (J-42) is re-dispersible and should only be used inside.

A: Solution: J-58 has a 30 minute gel time and would be applicable for an overhead bonder application. "Solution: J-58 will not loose bond strength if the concrete surface has no standing water, and the J-58 must be scrubbed into the concrete surface when it is wet to assure bond.

A: Ans. ASTM C-881 has 3 performance categories; Type, Grade and Class. Basically, *Types I and II are high modulus epoxies for use in non load-bearing applications; Type III is a low modulus for overlays and patching while types IV and V are high modulus epoxies for use in load bearing applications

There are 3 Grades:

1 = low viscosity

2 = medium viscosity

3 = Non-Sag (Gel)
Basically there are 3 classes

A = use below 40°F

B = 40 – 60°F

C = Over 60°F


Dayton Superior products meet the following ASTM 881 Specs:
Types I, II, IV, V, Grade 3, Classes B&C: J-50, J-51
Types I, II, IV, V, Grade 2, Classes B&C: J-58
Types I, II, IV, V, Grade I, Classes B&C: J-56
Type III, Grade I, Classes B&C = J-57

A: The Sure Level Epoxy (J-57) is a low modulus epoxy that is recommended for any exterior use. Use ±50 lbs. of clean dry quartz/silica sand per 1 gallon of J-52 Epoxy.

A: It is recommended to use a Grade 2 or a medium viscosity material for there is not enough ‘body’ in a low viscosity material for a proper bond. Typically bonding agents are applied at ±80 sf/gallon and a low viscosity material is not suitable for this type of build up.

A: Yes, it is necessary. By mixing each component prior to blending you are more assured that you will have all the ingredients suspension when blending to provide a homogenous mix.

A: NO. The surface must be clean and sound. ACI 503 states “Concrete surfaces to which epoxies are to be applied shall be newly exposed parent concrete free of loose and unsound materials. Prepare surfaces by mechanical abrasion.

A: Yes. ACI 503 states “Evaluate moisture content for concrete determining if moisture will collect at bond lines between old concrete and epoxy adhesive before epoxy had cured. This may be accomplished by taping a 4’ x 4’ polyethylene sheet to concrete surface. If moisture collects on underside of polyethylene sheet before epoxy would cure, then allow concrete to dry sufficiently to prevent the possibility of a moisture barrier between old concrete and new concrete.”

A: Yes. Epoxies are both mass and thermally dependent. The more mass the greater the exotherm (heat) that develops and the higher the temperature the faster it will harden and conversely, the colder the temperature the slower it sets.

A: After mixing the epoxy you can separate it into smaller pails reducing the mass and giving you a little longer ‘pot life’. Preconditioning of the material is very helpful also. Keep the epoxy cool in warmer weather to give you more time before it ‘tacks off’. In colder temperatures keeping the material warm will help to accelerate the set time.

A: The Sure Anchor I (J-51) is a gel (grade 3) epoxy that is excellent for vertical/overhead use. The J-51 meets ASTM C-881 and is ICBO approved.

A: AASHTO is an acronym for American Association of State Highway and Transportation Officials. The AASHTO M-235 Specification is the equivalent to ASTM C-881.

A: No. C-881 requires an epoxy to be less than 2000 centipoise (cps) in viscosity to be considered “low viscosity”. Epoxies with a viscosity greater than 2,000 cps, but less than 10,000 cps, are considered a Grade 2 or a medium viscosity material. Therefore an epoxy with a viscosity of 70 cps, or one of 1999 cps are both considered a ""low viscosity” but one will readily notice the difference.

A: ľ Problem: Epoxies are two component materials with mix ratios, and the colors are also in two components. If the mix ratio is varied slightly by not thoroughly cleaning the individual containers, there will be variations form container to container.ľ Solution: When using an epoxy that will be exposed, each container must be meticulously incorporated into the end use product. Use Poxy-Plus (J-36) from as large a container as possible to be applied within the pot-life to insure color uniformity.

A: ƒæ Problem: Cartridges are filled by machine that fills each side of the cartridge with a set weight of product. This is difficult if not impossible in the field.ƒæ Solution: There are bulk dispensing equipment available throughout the US for different mix ratio epoxies. Dayton¡¦s epoxy products are available in bulk: J-50, J-51, J-56 are available in cartridges. When the static mixer is used with the cartridges, and the first ounce or two is not used, the product is properly proportioned. The static mixer can be discarded, the caps put on both components and the cartridge can be stored and used when the caps are removed and a new static mixer installed.

A: ľ Problem: In any grouting operation, the product must be homogeneous to produce consistent bearing. A lower viscosity epoxy can easily settle. When the aggregate separates from the epoxy resin the grout is not homogeneous.ľ Solution: J-54 should be used as if it were a dry-packed cementitious grout. The formwork needs to be anchored on three sides and the J-54 packed or rammed into place.

A: J-50, J-51, J-54 resin and hardener, J-56, J-57 and J-58 should be mixed for three minutes with a Jiffler mixer

A: Problem: If the fresh concrete is formed and reinforced, the formwork would have to lowered, the epoxy applied, the formwork and reinforcing installed, and all need to be accomplished within the gel time of the epoxy, which are usually 30 minutes.

A: Problem: Neat epoxy coatings produce a very slick surface. Solution: J-57, and Poxy-Plus will accept sand broadcast into them, but either requires a second coat, within 24, after the excess sand has been removed. The objective is to encapsulate the sand to the point where each grain is 50% embedded into the epoxy.

A: Problem: 100% solid epoxies will not freeze, but they are difficult to bring back to a workable temperature in a hurry. Solution: J-50, J-51, J-54, J-56, J-57 and J-58 will not freeze, but J-36 will freeze.

A: Epoxies are diluted with diluents. Solution: DAYTON-SUPERIOR CORPORATION does not recommend diluting epoxies.

A: Blistering can be caused by not mixing until there are no streaking of the components or if the epoxy is not homogenous. Blistering can also result from placing a bonder on concrete in hot weather in direct sunlight. Aggregates absorb heat and can often be at a much higher temperature than the cement paste matrix. The epoxy bonder that is directly over the hot aggregate blisters by exceeding the temperature at which the epoxy, a thermo-setting plastic, sets. Solution: Mix Resi-Bond (J-58) in accordance with the instruction on the Technical Data Sheet or on the container (three minutes with a paddle or Jiffler mixer). Do not apply to concrete in direct sunlight in hot weather.

A: Problem: Epoxies bond in direct proportion to the surface area that is to be bonded. Smooth dowels, reinforcing bars and threaded rods all have different surface areas in the same diameters, and the unit with the greatest surface area bonds the best. Reinforcing has the greatest surface area, threaded rod has greater surface area than smooth dowels. Solution: Use Sure-anchor I (J-51) with reinforcing bars in control joints, use threaded dowels if a coil tie or coil anchor is used and a smooth dowel should be used in a contraction joint, and don’t for get to grease the non-anchored end of the smooth dowel so that it can allow the concrete to move horizontally but not vertically.

A: High modulus epoxies oxidize in ultra-violet light and chalk. Chalking continues to a certain depth and ceases, and is more of an aesthetic conditions rather than a structural consideration. Solution: Use a low modulus epoxy like Sure-Level Epoxy (J-57 when the application is exposed to the weather.

A: Problem: When water mixes with cement, the paste that is formed shrinks. Non-shrink grouts compensate for shrinkage by some form of expansion. Expansion can be in the plastic state, before initial set, it can be between initial set and final set, the aggregates can oxidize to produce expansion, or if gypsum is used, hydration takes place, attaching molecules of water to the calcium sulfate molecule, increasing its mass.

Solution: Do not use non-shrink grouts for patching unless the grouting area can be restrained through formwork or is placed beneath something. Both Sure-Grip High Performance Grout and 1107 Advantage Grout can be easily pumped into a formed area, provided there is both an entry port and an exit port.

Solution: Use patching compounds such as HD-50, Perma Patch, Polyfast, HD-25 or Thin Resurfacer.

A: Problem: When a non-shrink grout is placed in an area that is not restrained by formwork or placed underneath something, the movement created by expansive properties, without restraint, produce cracking. Non-shrink grouts are expansive because when the water and cement mix the mixture shrinks. There are four methods of expansion: 1. Aluminum powder produces hydrogen gas that produces expansion in the plastic state, 2. Shrinkage compensating admixtures or type K cement, 3. Metallic aggregates that oxidize to produce expansion and 4. Gypsum which takes on water molecule which attach themselves to the gypsum molecule in the process call hydration.

Solution: Trim off excess non-shrink grout, in un-restrained areas after initial set. Initial set in both Sure-Grip High Performance Grout and 1107 Advantage Grout is about 3 hours at 70 degrees F.

A: Problem: When a an oxidizing metal such as iron is used as aggregate in a non-shrink grout, the oxidization of the iron will continue until the source of oxygen is eliminated. Placing a cementitious cover is common practice when an iron (ferrous) aggregate is used. The degree of oxidization was measured by establishing a torque limit on the bolts that positioned and leveled the base-plate or anchor a machine.

Solution: Sure-Grip Metallic Grout does not contain a totally oxidizing aggregate such as iron, but contains metals that partially oxidize. Therefore, it does not have to be capped. The metal aggregate used in Sure Grip Metallic Grout oxidize only to a depth of one to two outer molecules at the surface of the metal, similar to but not the patina on copper.

A: Problem: Before the advent of plasticizers, the more fluid the consistency of a grout, the lower its strength. Most engineers wanted the highest possible strength. The Corps of Engineers established four consistencies for grouts, CRD C 621: dry-pack, plastic, flowable and fluid. The consistencies are qualified by test. Dry-pack, plastic and flowable are tested by a drop table. The drop table has an inscribed circle that is 12” in diameter and a 2”x2”x2” cube of grout I placed in the center of the circle. If it fills 40% of the circle it qualifies as dry-pack. If it fills the circle, it qualifies as plastic, and if it flows to 40% greater than the circle it qualifies as flowable. A flow cone is use to test the fluid consistency and the grout needs to flow completely through the cone in 30 seconds to be classified as fluid. The cone is 6” in diameter with a 45 o angle cone and 1” orifice. Grout is filled to the top of the truncation. Dry-packing is difficult when plasticizers are used as the plasticizers lubricate the aggregate and cement particle producing fluidity, even at low water ratios.

Solution: Dayton Superior Corporation produces Sure-Grip Dri-Pak grout for applications requiring a low viscosity consistency, but will not flow. It does not contain plasticizers, but requires restraint that is adequate to withstand the pressure required of dry packing.

Solution: Sure-Grip Utility Grout can also be dry-packed, or used in either a plastic or flowable consistency.

Solution: Sure-Grip High Performance and 1107 Advantage Grouts can be dry packed, with great care, but were designed specifically for use in flowable and fluid consistencies.

A: Problem: Grouting is essentially a repair operation, and the most important component of concrete repair is surface preparation. The second most important component of concrete repair is curing and protection (ACI 546).

Solution: Simply put, concrete repair requires that, the degree of moisture- saturation in the substrate to be equal to the moisture saturation of the repair material or the substrate will draw water out of the grout thus causing it to weaken or fail. Bonding compounds such as Ad-Bond (J-40) decrease the need for full saturation of the substrate.

Solution: Sure-Grip High Performance and 1107 Adva