When a crack affects the performance of the structure, we will repair it to restore its structural properties. Epoxy injection is usually the basis for this type of repair, with or without additional reinforcement. Injected epoxy is actually stronger than concrete and can restore concrete strength, but if there is an underlying problem, such as an overloaded structure or some moving condition, the concrete will simply crack again at another location. With any concrete repair, take that lesson seriously and you'll have a good start.
First find out what caused the damage, make the necessary preparation to eliminate any defective concrete and contamination, then install a repair designed to solve the problem. The worst thing you can do is make a repair that doesn't last. Someone once told me that more than 50% of concrete repairs fail again in two years. That is not a trajectory that inspires confidence.
For some concrete repairs, the best repair material is simply high-quality concrete. However, manufacturers have developed some excellent repair materials including several polymers that lead to increased bond strength and durability. Most current repair materials are polymer-modified concrete, which means that the base material is a mixture of Portland cement and aggregate with an added polymer (usually latex). The strength, adhesion, shrinkage, color, and appearance of the repair material must be compatible with the original concrete, and this is where concrete suppliers can help.
However, if minor defects are commonly seen in your concrete products, you haven't fully addressed the root of the problem. It is recommended to follow proper concrete repair procedures as per current practice before and during any FRP repair. Concrete repair is the process of fixing a hardened concrete surface that, over time, has lost the ability to hold bonding concrete materials together due to damage or environmental exposure. In addition, several concrete beams, with the same composition of the Pull-Off substrates (Table 12, and with dimensions of 100 x 100 x 1000 mm3), were cured with water for 28 days until tested for flexural strength.
Concrete repair and rehabilitation activities contribute to the depletion of natural resources and produce massive amounts of CO2 emissions and inert waste. The bond strength depends on the characteristics of the repair material and the surface roughness of the concrete substrate. If the cross section of the steel has been significantly reduced, new steel will be attached to the existing steel before replacing the concrete. Concrete repairs are often perceived to lack both early performance and long-term durability due to the brittle nature of concrete materials.
Thorough, clean and damp: this is the condition you want your existing concrete to be in before repair. You can then drill core samples for analysis in the laboratory or by a petrograph (someone who studies hardened concrete using microscopy). When a thin layer of repair concrete is to be applied, for example, a bonding agent 2 inches thick or less should be used. In addition, ECC's ability to outperform concrete in real-world repair applications verifies its long-term potential.
Prior to FRP repair, the reader should refer to relevant documents, such as those published by the American Concrete Institute. Proper vibration of fresh concrete is an important process to ensure optimal strength, durability and appearance of quality concrete products. .