RepCon 928 (Pack of 6)

Application

Surface Preparation

• Clean the Surface: Ensure the concrete is sound, free from oil, grease, dust, laitance, or contaminants. Saw cut the perimeter of the repair area 1/8” deeper than the repair depth for a notched edge, enhancing durability.
• Abrade the Surface: Mechanically abrade to a minimum Concrete Surface Profile (CSP) of 5, following ICRI 310.2 guidelines, ensuring a saturated-surface-damp (SSD) condition without standing water.
• Steel Reinforcement: Clean exposed steel of rust and apply SpecPrep SB. Apply a spray or brush coat of SpecPrep SB to SSD concrete and proceed with the repair mortar application wet on wet or within the open time specified in the SpecPrep SB datasheet.

Mixing and Application

• Mixing Instructions: Use 4.75 to 5.0 pints (up to 5.25 pints for non-DOT, more flowable applications) of clean water per 50-pound bag. Mix with a low-speed drill or mortar mixer, adding water to the container first, then gradually the RepCon® 928 powder. Mix for 2-3 minutes until homogenous.
• Application Depth: Apply from 1” to 2” without aggregate extension. For deeper repairs in heavy traffic areas, extend with clean, SSD 3/8” aggregate up to 60% by weight for over 1” repairs or up to 100% for over 4” repairs, mixing for an additional 2 minutes. Pre-dampen the aggregate and adjust the mixing water accordingly.

Placement

Firmly trowel or screed RepCon® 928 into the area, ensuring full contact with the surface. Allow initial set before finishing with a hand trowel. Excessive troweling isn’t required.

Finishing and Curing

Match the texture with surrounding concrete without adding water during finishing. Use SpecFilm as a finishing aid if needed. In DOT applications or severe conditions, use an ASTM C309 compliant SpecChem curing compound.

Test Data

• Initial setting time of 40 minutes, with a final set at 45 minutes at 70°F, as per ASTM C266.
• Achieves a compressive strength of 3200 psi in 3 hours, progressing to 9625 psi over 28 days.
• Bond strength of 2245 psi after 7 days, in accordance with a modified ASTM C882.
• Flexural strength measured at 1250 psi within 7 days, increasing to 1350 psi by 28 days.
• Demonstrates nearly 100% durability after 300 freeze-thaw cycles according to ASTM C666.
• Exhibits low chloride ion permeability at 866 coulombs within 28 days.
• Modulus of elasticity stands at 5.5 x 10^6 psi, indicating significant resistance against deformation.