• Using a skid steer scarifying attachment or concrete milling equipment, mechanically scarify the base concrete substrate to a CSP 9 profile. A more rough, textured surface promotes better bonding of the high-strength topping to the base concrete.
• Installing Tapcon anchors around the perimeter of the scarified concrete slab helps increase the mechanical bond between the base concrete and the topping material.
• Metco Low-Mod Epoxy Bonding Agent should be used to bond a high-strength concrete topping to a properly prepared concrete substrate, as shown in the installation video above. The combination of 100% solids epoxy and broadcast aggregate creates a tenacious bond to the base concrete.
• Acrylpave Bonding Agent can also be used to bond a high-strength concrete topping to a properly prepared concrete substrate. Acrylpave should be mixed with portland cement to a thick, slurry consistency. With a stiff broom, scrub the Acrylpave Bond Slurry into the saturated surface damp base concrete. Do not allow Acrylpave Bond Slurry to dry or puddle.
• Utilizing a concrete ready mix truck, allow the topping material to mix until a 5-inch to 6-inch slump is achieved. The powdered superplasticizers and low water-cement ratio will yield high ultimate strengths and increase durability against wear and abrasion.
• A heavy-duty power screed – roller screed, vibratory truss screed, etc. – should be used to place the topping in order to achieve maximum consolidation and density.
• Similar to ordinary concrete, when the topping will support a man and finishing machine, float surface with float shoes on trowel blades to consolidate surface and fill any imperfections. Trowel surface to produce a hard, smooth surface with subsequent finishing operations.
• Metalcrete Industries strongly recommends having an on-site product representative present during the concrete topping application. Having a Metalcrete representative on-site during the application provides the finishing crew direct access to a product specialist that can answer questions, offer experience-based advice, or provide general recommendations.