Repairs with composite materials – welding metal plates to concrete elements
RELATED MATERIALS
EPOMAX EK – two‑component epoxy putty
EPOMAX L20 – two‑component epoxy injection resin for gaps 0.1–1.0 mm wide
EPOMAX L10 – two‑component epoxy injection resin for gaps 0.5–3.0 mm wide
I. NATURE OF THE PROBLEM – REQUIREMENTS
Cracked structural elements may need strengthening by attaching thin metal plates to their surfaces. The bonding between the steel plate and the concrete must be strong, durable and free of voids. The repair system should accommodate small gaps between plate and substrate and restore the element’s load‑bearing capacity.
II. SOLUTION
Use stainless steel plates 1.0–1.5 mm thick and bond them to the concrete by injecting epoxy resins. Depending on the size of the gap, EPOMAX‑L10 (0.5–3 mm) or EPOMAX‑L20 (0.1–1 mm) is used as the injectable resin. The plates and voids around them are sealed and supported with EPOMAX‑EK epoxy putty before injection.
III. APPLICATION
1. Remove any existing plaster from the area where the plate will be installed.
2. Grind and smooth the concrete surface; then clean it thoroughly using high‑pressure water or compressed air.
3. Sandblast the inner surface of the steel plate to roughen it.
4. Mechanically fix the plate to the concrete with nails or bolts. Seal all edges with EPOMAX‑EK epoxy putty and install injection nozzles around the plate at intervals of about 20–30 cm.
5. After the EPOMAX‑EK has hardened, inject the epoxy resin (EPOMAX‑L10 or EPOMAX‑L20):
• Insert the resin outlet tube into the first nozzle (start from one end if the plate is on the underside of a beam or from the lowest nozzle if it is on the side).
• Adjust the pressure pot tap to force resin into the nozzle until it flows out of the adjacent nozzle.
• Cap the filled nozzle, then repeat the injection at the next nozzle. Continue until all nozzles are filled.
• The next day, break off the nozzle projections and restore the plaster if needed.
IV. REMARKS
- To minimise thermal movement of the metal plate, replace the removed plaster with a 2 cm thick cement mortar reinforced with ADIPLAST polymer latex.
- The resin injection requires two people: one to hold the outlet tube and cap the nozzles, and another to control the pressure pot.
- Mix each epoxy component thoroughly; ensure complete mixing of components A and B.
- Do not pour EPOMAX‑L10 or EPOMAX‑L20 directly into the pressure pot; mix the two components in their container and then place this container inside the pot to avoid contamination and premature hardening.
- Take into account the pot life of the resin and the ambient temperature so it does not harden before injection is completed.
- Clean the pressure pot and equipment immediately after use with SM‑12 solvent.
- Wear protective gloves and goggles during mixing and injection, and follow the safety instructions on the product labels.
RELATED MATERIALS
EPOMAX EK – two‑component epoxy putty
EPOMAX L20 – two‑component epoxy injection resin for gaps 0.1–1.0 mm wide
EPOMAX L10 – two‑component epoxy injection resin for gaps 0.5–3.0 mm wide
I. NATURE OF THE PROBLEM – REQUIREMENTS
Cracked structural elements may need strengthening by attaching thin metal plates to their surfaces. The bonding between the steel plate and the concrete must be strong, durable and free of voids. The repair system should accommodate small gaps between plate and substrate and restore the element’s load‑bearing capacity.
II. SOLUTION
Use stainless steel plates 1.0–1.5 mm thick and bond them to the concrete by injecting epoxy resins. Depending on the size of the gap, EPOMAX‑L10 (0.5–3 mm) or EPOMAX‑L20 (0.1–1 mm) is used as the injectable resin. The plates and voids around them are sealed and supported with EPOMAX‑EK epoxy putty before injection.
III. APPLICATION
1. Remove any existing plaster from the area where the plate will be installed.
2. Grind and smooth the concrete surface; then clean it thoroughly using high‑pressure water or compressed air.
3. Sandblast the inner surface of the steel plate to roughen it.
4. Mechanically fix the plate to the concrete with nails or bolts. Seal all edges with EPOMAX‑EK epoxy putty and install injection nozzles around the plate at intervals of about 20–30 cm.
5. After the EPOMAX‑EK has hardened, inject the epoxy resin (EPOMAX‑L10 or EPOMAX‑L20):
• Insert the resin outlet tube into the first nozzle (start from one end if the plate is on the underside of a beam or from the lowest nozzle if it is on the side).
• Adjust the pressure pot tap to force resin into the nozzle until it flows out of the adjacent nozzle.
• Cap the filled nozzle, then repeat the injection at the next nozzle. Continue until all nozzles are filled.
• The next day, break off the nozzle projections and restore the plaster if needed.
IV. REMARKS
- To minimise thermal movement of the metal plate, replace the removed plaster with a 2 cm thick cement mortar reinforced with ADIPLAST polymer latex.
- The resin injection requires two people: one to hold the outlet tube and cap the nozzles, and another to control the pressure pot.
- Mix each epoxy component thoroughly; ensure complete mixing of components A and B.
- Do not pour EPOMAX‑L10 or EPOMAX‑L20 directly into the pressure pot; mix the two components in their container and then place this container inside the pot to avoid contamination and premature hardening.
- Take into account the pot life of the resin and the ambient temperature so it does not harden before injection is completed.
- Clean the pressure pot and equipment immediately after use with SM‑12 solvent.
- Wear protective gloves and goggles during mixing and injection, and follow the safety instructions on the product labels.
