Textile-reinforced mortars TRM

[edit] Introduction

Carbon fibre material has a wide range of applications, as it can be formed in various densities, shapes and sizes. Carbon fibre is often shaped into tubing, fabric, and cloth and can be custom-formed into any number of composite parts and pieces.

Carbon fibre sheets have historically been used to strengthen structurally deficient concrete structures. However, these sheets are typically applied with adhesives that can become dangerous in the event of fire. In additions, the sheets do not work well if applied on wet surfaces (they may even fall from the structure if they become too wet).

Textile-reinforced mortars (TRM), also referred to as fibre-reinforced cementitious mortars (FRCM)) or textile-reinforced concrete (TRC), are produced as a type of textile woven from carbon or other advanced fibres with an open-mesh configuration. This is then embedded in cement- or hydraulic-lime-based mortars.

Since 2000, textile-reinforced mortars have been explored as a potential replacement for fibre reinforced polymer (FRP) methods of reinforcing structurally deficient concrete. Generally, TRM has demonstrated its ability to strengthen concrete and masonry structures in a manner that offers protection from seismic activity. With the addition of thermal insulation materials, TRM may prove to be a valuable for building envelope energy retrofit purposes.

[edit] KICT TRM method

In 2018, researchers from the Korea Institute of Civil Engineering and Building Technology (KICT) led by Dr. Hyeong-Yeol Kim began developing a structural engineering method that combined a carbon fibre grid with cement mortar to create a new type of textile-reinforced mortar panel. In 2020, a patent for the technique was granted.

[edit] Thin panels

The KICT method produces thin precast panels made from a carbon fibre grid and a layer of cement mortar. It can then be applied as cast-in-place construction.

The thin panels (approximately 20 mm-thick) are put on the surface of the structure. The space between the panel and the existing surface is filled with cement grout which acts as an adhesive.

The carbon fibres and the cement mortar in the panels are highly resistant to fire and are generally considered noncombustible materials. These panels can be applied during any weather conditions and will stay in place even if water is trapped between the surfaces.

[edit] Test results

Tests conducted by the research team indicated that the failure load of concrete structures strengthened with the TRM panel increased by at least 1.5 times.

The durability test and analysis of the TRM panel indicates that the lifespan of the panel is more than 100 years. This increase can be attributed to the cement mortar, developed by KICT, which contains 50% ground granulated blast furnace slag, an industrial by product generated at ironworks.

[edit] Applications

This method of construction using TRM panels may be suitable for building facades or repairs. It could also be used as strengthening materials for other applications, such as highway facilities, car parks or other structures where there is exposure to extreme weather.

[edit] Production

The cement mortar used in the TRM panels is generally less expensive than conventional mortar. This may reduce construction costs by about 40% compared to existing carbon sheet attachment methods.

[edit] Related articles on Designing Buildings Wiki

• Carbon fibre.
• Concrete.
• Fire in buildings.
• Mortar.
• Polymer concrete.
• Reinforced concrete.
• Types of mortar.

[edit] External resources

• EU SCIENCE HUB, Strengthening of Concrete Structures with Textile Reinforced Mortars: State-of-the-Art Review.
• Justia, Patents Assigned to KOREA INSTITUTE OF CIVIL ENGINEERING AND BUILDING TECHNOLOGY.