American Concrete Institute - Latest News and Information
The video introduces RAP 14 hydrodemolition as an advanced method for concrete removal, outlining its application, safety protocols, and benefits compared with traditional jackhammer techniques. It emphasizes the need for thorough pre‑construction meetings and detailed planning to manage high‑pressure water jet systems safely. Key technical advantages include superior surface preparation that avoids micro‑fracturing, enhanced bond strength for overlays, and the ability to remove carbonated or chloride‑contaminated concrete without damaging reinforcing steel. Equipment operates at 15,000–40,000 psi with low water volume, and specialized robotic rigs can service bridges, tunnels, and curved structures while minimizing vibration. The presenter cites real‑world examples such as a bridge deck expansion joint, deck‑coating removal using a hydraulic deck mower, and vacuum‑assisted sludge capture systems. Safety measures highlighted include full PPE, de‑energized conduits, shoring considerations, and strict wastewater containment with discharge limits of ≤300 mg/L solids and pH control, referencing ICRI and ASM testing standards. Adopting hydrodemolition can reduce worker injuries, improve repair durability, and meet tighter environmental permits, but requires investment in specialized equipment and rigorous planning. This shift promises lower lifecycle costs and higher performance for infrastructure owners.
Benjamin Estrich, a structural engineer with Martin Martin Consulting, outlines RAP 13 – the methacrylate flood‑coat procedure used primarily on bridge decks, parking structures, and industrial floors. He emphasizes that the material is a sealer, not a structural repair, intended for...
The video introduces RAP 3, a guide to concrete repair using low‑velocity spraying, a technique that propels engineered cement mixes at roughly 20‑30 feet per second—significantly slower than traditional shotcrete’s 80‑100 fps. The presenter emphasizes that the method relies on pre‑packaged, water‑mixed materials...
