How to repair cracked concrete, spalled concrete, rusted bars. Easy, effective & practical solution

Summary

This video provides practical solutions for repairing concrete affected by rusting rebar and cracks. It explains the causes of concrete spalling due to rust expansion and outlines a step-by-step repair process, including removing loose concrete, cleaning surfaces, rust removal, applying a rust-resistant agent, and using high-strength polymer mortar for repairs. The video emphasizes the importance of proper techniques to ensure durable results and concludes with tips on curing the repaired area. Perfect for homeowners facing similar issues, it combines expert advice with accessible methods.

Takeaways

• 🛠️ Understand spalling: Concrete spalling occurs due to rust on rebar, leading to cracks and even falling concrete.
• 🔍 Identify the problem: Check for visible cracks and rusted rebar to determine the extent of the damage.
• ✂️ Step 1 - Chipping and Hacking: Remove loose concrete around cracks using chisels and hammers.
• 🧹 Step 2 - Surface Cleaning: Clean the area thoroughly to ensure proper bonding between old and new concrete.
• 🧼 Step 3 - Rust Removal: Use a wire brush and rust remover chemicals to clean rust from rebar effectively.
• 🛡️ Step 4 - Coating with Rust Resistant Agent: Apply zinc coating on exposed rebar to prevent future rust.
• 🔗 Step 5 - Applying Bonding Agent: Use a bonding agent before repair to ensure strong adhesion between layers.
• 🏗️ Step 6 - Repairing with Mortar: Prefer high-strength fiber-reinforced polymer mortar for repairs instead of traditional mortar.
• 💧 Step 7 - Curing: Water the repaired area twice daily for three days to ensure proper curing.
• 📢 Share and Subscribe: Encourage viewers to share the video and subscribe for more practical tips on concrete repair.

Q & A

What is the primary problem addressed in the video?

The video discusses the issue of concrete deterioration due to rusting rebar, leading to cracks and spalling in concrete structures.

What causes the expansion of rebar in concrete?

Rust forms on embedded rebar, increasing its volume significantly, which creates internal pressure and leads to cracks in the surrounding concrete.

What is the first step in repairing cracked concrete?

The first step is chipping and hacking away any loose concrete around the cracks to ensure a solid base for repair.

Why is surface cleaning important after removing loose concrete?

Surface cleaning removes any remaining loose material that could hinder the bonding between old and new concrete.

How should rust be removed from rebar?

Rust can be removed using a wire brush followed by a rust remover chemical, ensuring the rebar is clean before applying any protective coatings.

What is the purpose of applying a rust-resistant agent to rebar?

The rust-resistant agent, usually zinc, acts as a barrier against moisture and air, preventing further rust formation on the exposed parts of the rebar.

What is a bonding agent and when should it be applied?

A bonding agent is applied to ensure a strong bond between old and new concrete, and it should be applied just before the repair process while it is still tacky.

What type of mortar is recommended for concrete repairs?

High-strength fiber-reinforced polymer mortar is preferred because it provides better results than traditional mortar and prevents cracking.

What should be done if the repair area has excessive mortar thickness?

For excessive thickness, the repair should be done using shuttering methods, while conventional methods are suitable for thicknesses less than 2 inches.

Why is curing important after completing repairs?

Curing the repaired area for at least three days helps ensure proper hydration and strength development of the new concrete.