Concrete Surface Repair: Strategies, Materials, and Techniques
Module 4
Concrete Surface Repair Strategies
The repair strategy is built around an existing losing stock position and is constructed by purchasing one call option and selling two call options for every 100 shares of stock owned. We use repair strategies when there is a communication breakdown. We can also use repair strategies to prevent a communication breakdown. For example, a miscommunication, a word or phrase that was not clear, not being able to hear the speaker, not understanding the speaker, misunderstanding a situation, etc.
Concrete Surface Repair Materials
- Unmodified Portland Cement Mortar or Grout.
- Latex Modified Portland Cement Mortar or Concrete.
- Quick Setting Non-shrink Mortar.
Concrete Surface Repair Types
- Epoxy injection.
- Routing and Sealing of Cracks.
- Concrete Crack Repair by Stitching.
- Additional Reinforcement for Crack Repair.
- Drilling and Plugging Method.
- Gravity Filling Method.
- Grouting Method of Crack Repair.
- Overlay and Surface Treatments of Cracks.
Types of Stresses in Concrete
The types of stress are compression, tension, shear, bending, torsion, and fatigue.
Surface Repair Performance Requirements
- Proper protection to steel.
- Bond between parent and new materials.
- Dimensional stability.
- Sufficient resistance against most unfavorable environmental damage.
- Appearance of final product/member.
- Affordable and easy application.
What is Corbel Repair?
Corbels are short cantilever deep beam with a shear span, structural members commonly used in reinforced concrete and Precast concrete structures. As known, the corbels are widely used in industrial buildings and highway bridges.
Bridge Deck Repair Process
A deck is the surface of a bridge. A structural element of its superstructure, it may be constructed of concrete, steel, open grating, or wood. Sometimes the deck is covered by a railroad bed and track, asphalt concrete, or other form of pavement for ease of vehicle crossing. A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross.
Aspects of Selecting Repair Material
There are a number of factors such as strength, durability, thermal coefficient of thermal expansion, permeability, low dry shrinkage, chemical and electrical properties, curing, and cost that must be considered to select the most appropriate, compatible, cost-effective repair materials.
Significance of Load Carrying Capacity
Load-bearing capacity is the maximum ability of a structural member or material to take loading before failure occurs. For example, before the onset of unacceptable bending.
Significance of Service/Exposure Properties
Slowing down of the deterioration by providing protection. Local strengthening of the structure to make damaged elements structurally redundant. Modifications to prevent safety hazards or interruption of service resulting from concrete spalling.
Electro-Chemical Chloride Extraction
Electrochemical chloride extraction (ECE) is a process that extracts or removes chloride ions from chloride-contaminated reinforced concrete structures. An electrical current is applied between the embedded steel and an external anode as a rehabilitation option to mitigate ongoing corrosion of the embedded steel. Chloride extraction is carried out by temporarily applying an electric field between the reinforcement in the concrete and an externally mounted anode mesh. At low concentrations, chloride ion has little or no effect on the physical stability of concrete structure but it causes the corrosion of the reinforcing steel in the concrete but at high concentration’ especially at low temperature, it causes expansion and cracking in the concrete.
