Fibre Carbon Installation

FIBRE CARBON PLATE INSTALLATION Before Bonding Surface Preparation- the surface has to be clean, dry and mechanically strong and smooth. If the concrete has deteriorated in depth, remove the damaged part manually or mechanically. The surface shall tested before bonding works carry out, make sure the concrete substrate has a tensile strength of > 1.5Mpa. The frequent of test was 2 nos per 100m required or 2 nos per project. In this project, the S.O has requested 2 nos of pull-off test per span to ensure every span’s surface condition are known.

Substrate preparation Flatness of substrate (soffit of R.C Slab) The flatness of concrete surface shall check with the steel straight edge. With the over 2 meter length the out of plane measurement must not exceed 5 mm. For those greater than 5mm requires the use of a system approved leveling resin epoxy to touch up as the leveling base.

The surface preparation was mechanically grinded by power tool after the setting out and marked as per drawing and cleaned by solvent or air compressor.

During strengthening (Climate Check) The climate check is important to ensure the adhesive, Adesilex GP2 was fully bond to the substrate. The list to check before the slab is important especially the moisture concrete, MC (%), relative humility, RH (%) & Dew points (ºC). High moisture content might cause a vapor barrier between the Adesilex and the substrate which everyone doesn’t like. Humidity is simply vaporized water in the air. The percentage of water vapor in the air at a specific temperature, compared to the amount of water vapor the air is capable of holding at that temperature is most often referred to as “relative humidity.” When air is saturated with water vapor, it is said to have reached the “dew point.” At the dew point, water vapor condenses and produces visible water or condensation happened to the concrete surface. Surface substrate’s moisture content less than 4% because the presence of moisture may inhibit adhesion of primer, relative humility less than 80% and dew point more than 3ºC , if the dew point interval temperature was less than 3ºC, the substrate must be heated or relative humidity lowered.

The substrate (concrete slab temperature) and the dew points was measure, (34.6 -22.7) ºC = 11.9ºC > 3 ºC and the relative humility = 49.4% < 80% Moisture content of the concrete surface must be less than 4% M.C = 3.5%

Application Procedure The carbon plate is supplied in rolls that must be cut on site according to the designed and desired length with the electric saw fitted with diamond blade.

The carbon plate was cut to desired length and number before the installation started.

Plastic Sheet

Rough

The carbon plate was protected by the plastic sheet to ensure the surface was clean and rough for bond. The applicator only needed to peel the plastic before apply the adhesive, Adesilex GP2.

Preparation of Adesilex GP2 Mix together the two components that make up Adesilex PG2, Part A and Part B. Pour the Part A into part A and mix with drill fitted with a stirrer until it mix perfectly smooth and even (the same colour grey throughout)

2mm gap allowed for adhesive to pass through

The applicator has custom made the steel mould distribute the adhesive evenly and equally to the carbon plate. The curve shape scraper was use to block the adhesive to pass by the gap of 2mm as the plat was pushing from one side to another side. Bonding the carbon plate E200 First, apply the adhesive on the substrates (concrete surface) with the scraper so the penetrating and contact to the adhesive is wholly. Use appropriate mixing tools, at correct speeds with the most appropriate mixing paddles, to achieve full and consistent mixing, without entraining excessive air.

Pushing direction

The carbon plates are pushed with the light finger pressure on to the concrete surface. The adhesive is thixotropic and will hold the carbon plates in place without the need for additional support.

Following this initial pressure, a hard rubber roller is used to press the plate into the adhesive from the centre to the both end in a manner, which cause the adhesive to be expelled at both edges of the carbon plate. This guarantees that the adhesive is applied thoroughly eliminating voids.

Roll to both end

Roll to both end

The expelled adhesive can be removed with a suitably shaped spatula or by hand. The adhesive layer thickness should average 2mm (minimum 1mm to maximum 3mm)

Seal the edge of strips and removed expelled adhesive.

For post inspection after strengthening, the applicator must check on the adhesive thickness and any voids between the strips and substrates. Besides, the pull off tests was required to carry out on the test specimens.

Average thickness =(3.01+4.02+3.41+3.07)/4 mm = 3.37mm – 1.4mm (Carbon plate thickness) = 1.97mm - Acceptable (1mm to 3mm )