Technical Solutions

carbon fiber reinforcement is better than traditional reinforcement?

Compared with the traditional reinforced concrete cross-section or reinforced steel concrete reinforcement, carbon fiber reinforcement has the advantages of space saving, easy construction, no need for solid steps on site, easy guarantee of construction quality, basically no increase in structure size and weight, good resistance to degradation, and long-term performance

(1) Carbon fiber reinforcement has high tensile strength, which is 7-10 times that of steel with the same cross section.

(2) Light weight, only 1/4 of the density of ordinary steel.
(3) The long-term carbon fiber reinforcement is good, which can resist the degradation of chemical degradation and the hostile environment and climate change.
(4) The construction is convenient and quick, labor-saving and time-saving, and the construction morality is easy to guarantee.
(5) Carbon fiber reinforcement has a wide range of applications, and concrete components, steel structures, and wooden structures can be reinforced. Can greatly improve the bearing capacity, seismic performance and long-term performance of components.


Carbon fiber reinforcement is the end of the damaged construction. Carbon fiber reinforcement treatment has become the most sought-after method of reinforcing and reinforcing structural members in the modern construction industry. Whether it is a large city or a small village, the built structure has cracked, damaged, or even broken the environment after a certain period of time due to weathering, excessive load, and unqualified materials, etc., bringing great safety risks to people's production and life . In order to guarantee the safety of people's lives and property, the most economical method is to use scientific skills to end the reinforcement and reinforcement of the damaged building components.

Plate series property
Plate series property: the remendy repair and strengthening of thr plate and beam of concrete structures; the strengthing of thr openings around the wall and plate; the strengthing of beam of wooden building; the remedy repair and strengthening of tunel and cable lines; the strengthening of bridge plate, bridge pier and girder.

Composite rebar series main applications
Composite rebar series main applications: construction,transporation industry, coal mine tunel,parking structures,half coal roadway,slope support,subway tunnel,rock srface anchoring,seawall and dam etc.

Unidirectional fabric series were widely used
Unidirectional fabric series were used in aerospace,building reinforcement and so on. The basic steps of project operation as below:
• 1.concrete surface preparation, crack repair, leak stop, get rid of the aged, loose
concrete part
•2. brush primer (0.2-0.4kg/m2)
• 3.base surface preparation( putty 1.0-1.5kg/m2)
• 4.brush epoxy resin on the surface(0.4-0.5kg/m2)
• 5.stick the carbon fiber fabric onto structure
• 6.saturate the fabric by brushing epoxy resin along the fabric, ensure that there is nobubble existing in the composite matrix( very crucial) 0.1-0.2kg/m2
•7.if more following carbon fiber fabric layer, brush 4-6times each layer
• 8.FRP wrap operation is completed, however, keep the structure from any impactduring the following 24hrs

Bidirectional fabrics series are widely used
Bidirectional fabrics series are widely used as the basic material for aerospace, defense, leisure, automotive products, industry and the medical sector as well as other applications includes building construction repair and strengthening.

Prestressed CFRP plate reinforcement system
Reinforcement of bridge’s prestressed Plate
Reinforcement of bridge’s prestressed Plate of Highway from Panjgur to Hoshab in Pakistan
1. Introduction 
No. 2 bridge Pakistan highway from Panjgur to Hosha is located in the place 8 kilometers away from Panjgur, leading to Hosha in the west, and the whole length of bridge is about 324.8 m.
However, for various reasons, the bridge had still not taken reinforcement renovation by March, 2016. From October 9, 2015 to November 2, 2015, the evaluation and bridge technique condition and load test were carried out. By comparison between the old and new test reports, bridge diseases are further serious, the quantity of cracks increases, and individual crack’s width is enlarged. The corrosive cracks of prestressed concrete box increase. Reinforced concrete cracks increase, the individual crack width. Structure concrete carbonation depth is increased, and the intensity is reduced. Bearing damage is increased, and bearing displacement is too large. The expansion cracks on the surface are seriously damaged. Main bridge’s bearing capacity is insufficient, and cannot meet the requirement of the designed load and carrying capacity.
2. Materials for Reinforcement
  carbon fiber plate, sticky trap glue, anchor plate and tensioning machine
3. Design of maintenance and reinforcement engineering 
Based on the check of overall bridge structure, it can be seen that the bridge has the problems of different degrees in structural safety, durability and driving comfort. In order to ensure the bridge structure’s security, durability and driving comfort, and a and properly recover the original functions of various bridge components, the bridge reinforcement shall be immediately conducted, further to prevent diseases from being more serious; otherwise the service life for the bridge’s structure safety and driving safety cannot be guaranteed. The scheme of using prestressed Plate for repair and reinforcement engineering is as follows:
In order to improve the whole strength of the bridge, enhance the bearing capacity of components and slow crack propagation, the measure of using bonded prestressed carbon fiber plate is taken to reinforce and maintain. Within the scope of beam bottom of the first stage of the main bridge (1st ~ 6th holes of the main bridge), the second stage (7th -11th holes of the main bridge), and the third stage (13rd-14th holes of the main bridge), the bottom of the beam, the prestressed carbon fiber plate is bonded forward the bridge. Within the scope of prestressed concrete continuous box beam bottom of the first stage and the second stage, six prestressed carbon fiber Plates are made for every piece of box beam bridge, and the thickness of each carbon fiber board is 1.4 mm, its width is 100 mm, and its length is 17000 mm. Within the scope of the beam bottom of simple supported-continuous small box of the third stage, two prestressed carbon fiber Plates are made for each small box beam bottom. The thickness of each carbon fiber board is 2.0 mm, its width is 100 mm, and its length is 22000 mm. The tension control stress of prestressed carbon fiber is 1000 mpa, and the control strain is 6‰. The measured value of tensile elastic modulus of carbon fiber plate needs to be higher than 160 gpa, and the fiber volume content should be higher than 70%. The prestressed carbon fiber board system uses the matching prestressed anchor plate and tensioning machine, but the single-ended tensioning or tow-ended tensioning are made at the same time. Anchor plate adapts alloy anchor plate with high strength and corrosion resistance; the fixed end and tensioning end use high-strength chemical anchor bolt and the concrete beam structure for connection.
Construction technique of bonded prestressed carbon fiber plate
(1)Construction preparation: It shall set up the construction stent, purchase the main materials and process and manufacture anchorage steel components. According to the condition on site, the construction stent that is suitable for construction shall be set up, with construction layout. In the reinforced beam surface, according to the design drawings, the construction layout is made. It shall determine the position of carbon fiber plate and anchorage on both ends.
(2)Processing of concrete surface: The concrete structure of beam steel is directly exposed to air with certain humidity for a long time. During the construction of bonded carbon fiber plate reinforcement, it needs to remove embrittled and loose layers, so as to enhance the cohesive force. For the embrittled and loose layers of concrete surface, it should use hard diamond grinding wheel to grind them out and make the new surface shown, as well as completely remove loose floating layer with a wire brush. In order to ensure the design gap between the carbon fiber plate and the concrete (rubber thickness is 3~5 mm), and realize the carbon fiber plate is straight and unimpeded when tensioning, the concrete’s high convex shall be polished by diamond grinding piece, and epoxy repair glue should be adopted to repair concrete low concave. If concrete humidity is bigger when it is bonded, manual dry processing should be made for the bonded surface of the concrete.
(3)In position for the tensioning end of carbon fiber plate and fixed-end components, drilling and planting are made for high-strength screw in accordance with the design drawing: the method of planting reinforced bars is used for installation, and the drill with the drilling diameter that should be matched with the bolt diameter is used for drilling; positioning and drilling of planting reinforced bars: before drilling, it shall determine the position of the bean steel and mark it; when drilling hole has contradiction with reinforced location, appropriate adjustment is made for the hole position, and it should be vertical to the beam body when drilling. The blower nozzle stretches into the bottom of the hole and the clean air is blown into it, pulling out of the nozzle, which is repeated three times. The scrub brush is inserted into hole, rotating flush back and forth for three times. The hair dryer blowing nozzle gets into the bottom of the hole, which is repeated 3 times;
The oil dust on the planting bolt should be cleaned up. Before planting the bolt, acetone is used to clean the hole wall, hole bottom and bolt. The special injector for planting glue is adopted for perfusion, and the amount is as much as two-thirds of the hole depth, ensuring a little glue overflows after implantation of bolt. After injecting glue, it shall immediately make the one-way rotating to insert bolt, until it reaches the design depth, to ensure the top of the screw is at the same plane, and correct the bolt verticality. Before the glue is cured, it cannot touch or vibrate the embedded bolt, avoiding the viscidity.
(4)After screw curing meets the designed strength, tensioning-end and fixed-end steel parts shall be installed: the grease is brushed onto the contact part of anchorage parts and the carbon fiber board; acetone is used to clean the surface of concrete parts contacted by the carbon fiber plate; carbon fiber board is installed on the fixed end and tensioning end, and carbon plate glue is made between the carbon fiber plate and beam bottom. After the glue for carbon fiber plate is primarily fixed, compression bar can be installed; when installing compression bar, shim is installed at the bottom of the anchor bolt to keep 0.8 cm gap between the bar and concrete crack, so that the carbon fiber plate can slide freely when tensioning. At the same time, before the compression bar and prestressed carbon plate, rubber piece is stacked to prevent carbon plate from being damaged. After compression bar is installed in place, jack is installed at tensioning end, to make sure that jack midline mergers with carbon fiber board line in a horizontal position, with pressure tensioning till 15﹪of the designed tension stress value, and the anchorage tensioning moves to the starting line. Pressure tensioning makes it reach 30% of the designed tension stress value; it shall check whether there is glue liquid extrusion overflow between the carbon fiber plate edge and the beam surface; if there is no liquid extrusion overflow for some parts, it shall relieve pressure and then make tension; it shall check whether anchorage displacement corresponds to prestressed tension.
Tension is increased with certain phrase until 50﹪, 70%, 90﹪ and 100﹪ of the designed tension stress value. After each level of the tensioning is finished, screw is fixed with a wrench, and sustained load between each level is five minutes, to record the location of the tension-end clamp, with the comparison of the deviation between measured and calculated value. It shall check whether the concrete displacement of tensioning anchorage meets the requirements of theoretical elongation; according to the requirements of specification, the error of concrete displacement of tensioning anchorage and theoretical elongation should be not more than ±10﹪.
When prestressed force is applied to 100%, the final carbon fiber plate’s tensile value is calculated, and the sustained load is 5 minutes. After the tension, double nut is used to fix tensioning screw. Jack is removed. Too long tensioning screw is cut,  and the back-end shall be 3 cm.
(5)Curing maintenance: the curing time shall be reasonably controlled based on construction environment temperature and material properties of carbon fiber composite plastic; when construction environment temperature is below 25 ℃, curing time shall be relatively longer. In carbon fiber plate’ prestressed tensioning system, anchorage are steel part, prone to rust. Because carbon fiber plate is resin composite, and should avoid the erosion of ultraviolet ray; after completion of tensioning inspection, epoxy resin mortar with good cohesiveness, anti-corrosion and good durability is used, and the not less than 3mm epoxy resin mortar is coated for anchorage and carbon fiber plate.

Application of 400g unidirectional
Application of 400g unidirectional prepreg to anticorrosion for oil pipeline in Dubai

In 2015, Dubai Petroleum Pipe Line Administration found mechanical damage in somewhere of oil pipeline in routine inspection, where the outside diameter of pipeline was 559mm and normal wall thickness was 10mm. On the topmost of surface of pipeline existed recession due to mechanical damage. The recession was 15mm deep, and external diameter was about 200mm. The measurement result of pipeline wall thickness at the recession showed that the wall thickness of pipeline at the recession thinned by about 2mm. 

Application of carbon-fibre composite reinforcement technology to pipeline reinforcement is provided with following advantages:  
①Solderless without flame operation, able to restore in running status of being under pressure; 
②Simple and rapid construction and short operation time;  ③The characteristic of elastic modulus of carbon fibre being very close to that of steel makes the composite able to bear as much pipeline pressure as possible, reduce stress level of defected pipeline, and limit dilatational strain of pipeline;  
④With high tensile strength, the carbon fibre can realize extremely high security when applied to pipeline restoration; besides carbon-fibre composite has excellent creep resistance with strength basically unchanged with increase of service time;

⑤The reinforcement layer of carbon-fibre composite has small thickness, which can facilitate subsequent antiseptic treatment; 
⑥Carbon fibre reinforcement has flexible winding and laying modes, hence able to reinforce defects (including high welding seam reinforcement and severe misalignment)of circumferential weld and spiral welding seam, and restore irregular pipelines such as elbow, T-joint and reducers, etc.  
⑦Can be applied to restoration and reinforcement of defects such as erosion, mechanical damage and crack, etc. or applied to pressure lifting and reinforcement for the whole section of pipeline, showing the field of application is extensive.  

Reinforcement scheme

The research result by related departments is to emergently repair the pipeline using carbon-fibre composite 400g unidirectional prepreg reinforcement technology. The repair scheme is to first filling resin to fill and restore the recession, then wind high strength carbon fibre 400g unidirectional prepreg around the pipeline.  
 After establishing reinforcement scheme, used finite element analysis software to calculate and verify this scheme.    First calculated the stress distribution on pipe wall when flawless pipeline bears internal pressure. With pipeline in good condition, when it bears internal pressure of 3MPa, the loop stress in the pipeline should be 83.85MPa. Established finite element model to analyze this scheme. In the finite element model, simulatively calculated recession. To facilitate establishing model, took only one eighth of pipeline to establish model.  
   In finite element model, took 207GPa for elastic modulus of steel material, 0.3 for Poisson ratio, and 450MPa for yield strength. Set the running pressure in pipeline as 3MPa, number of reinforcement layer for carbon-fibre composite as 6. According to above conditions, obtained the distribution nephogram for hoop stress in non-reinforced pipeline and reinforced pipeline.

The calculation result showed that severe stress concentration existed at the edge of recession in non-reinforced pipeline. The maximal hoop stress reached 322MPa, far exceeding the hoop stress for pipeline wall when flawless pipeline bore pressure of 3MPa.  And this stress was close to yield strength of steel material. When the internal pressure fluctuated in the pipeline, endurance failure was deadly easy to occur at stress raisers under action of fatigue load.  If it is not reinforced, the wall thickness at recession may continue to reduce, rendering the stress concentration at pipeline recession more severe.  
  After reinforced with carbon-fibre composite, the pipeline's loop stress reduced significantly, with the hoop stress in the most severe region being 164MPa. This stress was lower than yield strength of steel material, and pipeline distortion was still within elastic range. After reinforced, the pipeline's stress concentration will be largely alleviated, and the pipeline will be in safe range of stress. 

The construction flow after the reinforcement scheme is established is: 
①Pretreat the external surface of pipeline to remove erosion resistant coating; 
②Use electric descaling tool to burnish the surface of pipeline, to reach descaling requirements of St3 level;  
③Use cleaning agent to clean the surface of pipeline and dry it intensively;  
④Smear filling resin at recession, repair till the surface of defected position is leveled off;  
⑤After the filling resin is solidified preliminarily, wind high strength carbon-fibre composite and guarantee the composite covers the defected position, wind 6 layers;  
⑥Make antiseptic treatment for the reinforced area, then backfill.  
After restoring above defected pipeline by reinforcement, the pipeline's normal running pressure was restored with satisfactory effect.

600g unidirectional carbon fiber cloth
Singapore international convention center Reinforcement with 600g unidirectional carbon fiber cloth

I. Project overview

Being the largest exhibition hall in Asiaand one of key investment projects of government, Singapore Expo was put into formal use in April 2002 with a total investment of 220 million SGD, standing 25 hectares. It incorporates an exhibition hall of 60,000 sqm and an outdoor saloon of 25,000 sqm, 10 meeting halls of varying sizes and 9 parlors, equipped with advanced translation, communication and transmission facilities.  Besides a parking lot  able to accommodate 2,200 cars and two taxi stations, the expo center also possesses the second largest dining hall inSingaporewhere 10,000 people can have diner, to provide the exhibitors with commercial meal service of different levels. 

Due to frequent use, the exhibition hall was not maintained and reinforced for more than one decade. Considering more exhibitions in future and huge visitors flow rate every day, the building began to be refurbished and reinforced in May 2014. 

II. Reinforcement material

600g unidirectional carbon cloth and carbon fiber glue

Major mechanical property indices

Object name

Normal value for tensile strength (MPa)

Elastic modulus





Bend strength


Interlaminar shear stress


Normal tensile cementation strength of fiber composite and concrete(MPa)

Carbon cloth (grade)







and is concrete cohesive failure

Design of maintenance and reinforcement work

The general structure inspection shows that the building of exhibition center has problems of varying degrees in structural security and endurance.  To guarantee security and endurance of building structure and restore original functions of each part of building, the building should be immediately maintained and reinforced to hinder the damage from further developing, or the buildings' structure is not secure enough. The design scheme of reinforcement using carbon fiber unidirectional cloth reads as follows: 

After sealing the surface for the crack of building, paste carbon cloth to the beam segment where crack spreads. Define scope of pasting carbon cloth to beam bottom according to the detection conclusion and technical parameters provided by the detection unit. Paste carbon cloth to general column position where the structural crack locates according to the position of structural crack as specified in detection report, with primary load bearing wall in basement pasted with carbon cloth. 

III. Construction process of pasting carbon cloth

1.Measurement engineering: loft on bridge-girder according to the position of pasting carbon fiber defined in construction drawing, draw up area of pasting carbon fiber, process this area, the four corners for pasting area and column all need to be rounded with radius of rounded angle being 20mm. The requirement on accuracy of measurement: the error shall not be greater than ±10mm.   

2Facing treatment: the surface of concrete in the construction operation area shall be burnished using angle grinder with burnished depth not smaller than 0.5mm. The burnished surface layer shall be complete without any adhering laitance layer, loose material, dust, oil or grease. The ash and loose materials shall be removed with air pressure nozzle and brush. After burnishing the facing, the dust on the surface shall be thoroughly cleaned away using forced-draft fan or dust collector and kept dry. The surface smoothness is required to be less than or equal 5mm/m. The sticking place of corner and concrete surface shall be rounded and burnished to be arc-formed, with radius beam of arc not smaller than 20mm. 

3Crack restoration: When pasting carbon fiber to the elastic crack which has been tightly sealed, seal by fully brushing the whole area. 

4Shearing of carbon cloth

(1)Shear carbon cloth strictly according to the size required by design. 

(2) Bevel shearing carbon cloth is strictly prohibited and wire drawing shall be prevented; 

(3)Keep the sheared and shaped carbon cloth clean from pollution. 

5Prepare and brush primer

(1)Prepare base glue strictly according to the process stipulation provided by the manufacturer

(2)Smear evenly priming resin on the surface of concrete using roller brush. After the surface of primer is dry to touch, go to next step as soon as possible.   


(1)Prepare leveling material strictly according to the process stipulation provided by the manufacturer

(2)For repairing surface of concrete, adopt acetone to wipe off the floating dust on surface, use leveling material to fill up the surface depression, the position with offset or corner shall be made into smooth curve surface instead of having edges and corners.   

(3)Use leveling material to restore corner into slick circular arc with radius not smaller than 20mm.   

(4)Use scraper with tool tip width ≥100mm to fill up, repair and level the depression, the leveling degree shall be without obvious trace of scraper blade or scraper and grain being smooth.

(5)After the surface of leveling material is dry to touch, go to next step as soon as possible. 

7Prepare and brush impregnating resin or pasting resin  

(1)Read carefully the working instructions provided by manufacturer before preparing agglomerant

(2)Define the intermixed quantity of resin each time according to actual onsite environment temperature and pasting area to avoid failure and waste.   

(3)Measure and prepare strictly according to proportion by weight

(4)Prepare according to mixing proportion of manufacturer and technological requirements, and arrange special personnel for watching. Oily soil and impurities shall not exist in whipping container and on beater. Whip clockwise unidirectionally till the color becomes uniform without bubble produced, and prevent dust or other impurities from getting in.   

(5)Use up the prepared agglomerant as required within controlled use hours. 

(6)Wipe again the surface of concrete to ensure no ash on pasting area before pasting carbon fiber

(7)Evenly smear the impregnating resin prepared according to the process stipulation provided by manufacturer to pasting area. When brushing structural adhesion to surface of concrete, brushing must be stable, accurate and even, i.e. stable: brush with moderate force without flowing, dropping or falling as far as possible; accurate, brushing is within control line; even: the thickness pasted within brushing scope is even.   

8Paste carbon cloth

(1)Lightly paste carbon cloth to the required position with hands. Pasting carbon cloth is also required to be stable, accurate and even. Unwind with moderate force to make carbon cloth not crinkle or fold and spread smoothly. Adopt dedicated roller to roll along direction of fiber. One must roll from one end to another end, and it is inadvisable to repeatedly roll and knead one position. In rolling, make glue permeate the fiber cloth, to realize plump soakage and make bubble extruded, make impregnating resin fully saturate carbon cloth. Don't damage carbon cloth in rolling. When carbon cloth needs to be lapped, all circumferential lap length shall not be smaller than 200mm.    

(2)Repeat above steps for pasting multilayer, and it is advisable to paste the next layer as soon as possible after the impregnating resin on fiber surface is dry to touch  

(3)Evenly smear impregnating resin on the surface of the last layer of carbon cloth

 9Completion: Maintain for 48 hours, during which time the carbon fiber surface shall be prevented from being scraped or touched by sharp objects and pulled artificially. To facilitate subsequent concealed construction, during 6-12 hours after carbon cloth is pasted, spray sand to carbon cloth to coarsen it to the degree that it is viscid to touch. 

10Construction technique measures and key quality control points

(1)The conformity certificate for leaving factory for raw material of carbon fiber and performance indices in product quality detection report must be inspected and checked when material is delivered to the site.   

(2)Surface treatment of substrate concrete is one of the most critical procedures in reinforcement with carbon cloth, which shall be taken seriously. Remove thoroughly the floated coat to expose concrete structure layer, and weed out the poor concrete such as stripped, loosened, beehive and eroded concrete on the surface of to-be-reinforced member. Level off with epoxy resin mortar. If the member has crack, first conduct crack pouring or joint sealing, then burnish to be leveled, clean impurities off, and keep dry. The base plane is required to be leveled off and continuous without recession, and internal and external corner shall be smooth.   

(3)Prepare the glue used for pasting carbon fiber strictly according to product description. The field environmental conditions shall conform to product requirements.   

(4)Prepare a small amount of adhesive each time, as the remnant adhesive and the adhesive exceeding operable time of glue shall not be reused.   

(5)The lap length of carbon cloth in the impact direction of fiber shall not be smaller than 200mm. 

(6)To guarantee carbon fiber sheet can reliably coordinate with concrete, additional anchorage measures can be taken.   

(7)Blank accurately. The carbon cloth strips with uneven edge and recessed and convex corners are prohibited to be used. 

(8)In pasting carbon fiber, rolling must be done properly in place to guarantee fiber material is fully steeped for effective pasting.   
(9)Enhance inspection and acceptance of pasting work of carbon fiber. The quality of bonding between carbon cloth and concrete shall be inspected using hammer to knock or using hands to press the surface of carbon cloth. The total active area shall not be smaller than 95%.  When the hollow area of carbon cloth is smaller than 10000mm2, one can remedy by injecting glue via needle tube. When the hollow area is greater than 10000mm2, it is advisable to cut off the carbon fiber sheet at hollow area, and re-lap with equivalent carbon fiber sheet with lap length not shorter than 100mm.

Aramid Glass Hybird Fabric
Aramid Glass Hybird Fabric Reinforcement on Old Bridge of Changwat Suratthani,Thailand

1Project outline

In March, 2011, the flood disaster in the south ofThailandwas severe, as of 29 a total of 10 people died from unremitting six-day flooding. Especially Changwat Suratthani, where the impounded surface water reached up to 3 meters because of the flood and a lot of bridges were destroyed. In order to speed up the strengthening process of bridges and improve the flood control ability, undirectional reinforcement of glass fibre is adopted.

    The loading text on the first step of first page and the second step of third page of the main bridge is conducted after detecting the bridge, according to loading test results, the strain calibration coefficient of principal measurement point at controlling section of the first step of first page of main bridge is greater than 1, the relative residual value of strain and deflection is less than 20%, and the strain and deflection calibration coefficient of principal measurement point at controlling section of the second step of third page is greater than 1, the relative residual value of strain and deflection is less than 20%. The bearing capacity of this bridge is insufficient.

    The bridge pier and beam column are also subject to different degrees of damage, which made a serious impact on stability of the bridge as well as on safety and smoothness of vehicle driving, under the strike of the flood.

2Reinforcement materials

 Main mechanical performance index

Product name

Standard value of tensile strength (MPa)

Elasticity modulus (Gpa)

Elongation (%)

Fabric (I class)




 Engineering design of maintenance and reinforcement

The scope of pasting fabric at beam bottom is determined according to detection conclusion and technical parameters provided by testing unit. An overall fabric is pasted at the position of its bridge location according to structural crack location in the report (the 13th hole of right width and 14th hole of left width of main bridge, 5th hole, 7th hole and 14th hole of ramp), of which for the reason that the 13th and 14th hole have pasted prestressed glass fiber board in the third page of main bridge, the fabric is only pasted on the 12th and 15th hole, the 5th hole of Z ramp being the first page, the 7th hole being the second page and the 14th hole being the third page, therefore, the fabric is pasted on all lines at ramp.

3Construction technology of pasting fabrics

3.1Surveying engineering: make a lofting on the bridge according to the location of pasting fabrics confirmed in construction drawings, draw out the area of pasting fabrics and carry out the construction process to paste the area, the four angles of the column are required to be circular bead with radius of 20mm. Measurement accuracy required: the error is no greater than ±10mm.

3.2.Surface treatment: the concrete surface within construction work area are all polished with angle grinder, the polishing depth shall not less than 0.5mm, and the surface layer is required to be intact without any plasma skin, loss mass, dust oil and grease. Use air compressor nozzle and hairbrush to eliminate the dust and loss materials. There’s a need to adopt ensilage dump blower or dust collector to completely sweep away the surface dust and keep dry. The surface evenness is required to be equal or lesser than 5mm/m. At the paste location of intersection angle, a bevel process is carried out on the concrete surface to polish into arc shape, which the the radius of beam is not less than 20mm.

3.3 Crack repair: as to elastic fracture sealed, make a closed repair with full-brash way of the whole area while pasting fabrics.

3.4Clipping of fabrics

1Tailor the fabrics in strict accordance with the size the design required.

It is strictly forbidden to chamfer the fabrics and prevent it from wiredrawing phenomenon.

Pay attention to keep the tailored fabrics clean without pollution.

3.5 Collocate and brush underlying glue

Collocate the underlying glue in strict accordance with process stipulation provided by manufacturer.

Use roller brush to evenly paint on the concrete surface with underlying resin. Carry out the construction of next process as soon as possible after being confirmed to be dry with finger touching on glue surface.

3.6 Leveling materials

Collocate leveling materials in strict accordance with process stipulation provided by manufacturer.

The repair on concrete surface selects acetone to wipe off the floating dust on the surface, use leveling materials to fill the surface indentation, smear it as smooth hook face without edges and corners in the position of segment difference and intersection angle.

Use leveling materials to restore as smooth arc at intersection angle, the radius is greater than 20mm.

Use the scraper, whose the width of tool bit ≥100mm, to repair and level, the leveling degree is subject to the grain of unobvious trace of scraper blade and scarping knife by visual inspection.

Carry out the construction of next process as soon as possible after being confirmed to be dry with finger touching on surface of leveling materials.

3.7Collocate and brush impregnating resin or paste resin

Please read the operating manual offered by the manufacturer carefully before collocating the binder.

 Ensure each mixing amount according to the actual environment temperature on the spot and paste area in order to prevent waste.

Collocate in strict accordance with metering of weight ration.

Collocate according to mix proportion offered by manufacturer and technological requirements and there must be a special person responsible for it. There shall be no oil and impurities in the mixing container and on the stirrer. Stir it towards one direction (clockwise) until the color and lustre are equal without bubbles produced, and prevent dust and impurities from sneaking into.

The binder collocated shall be used up within service time as required.

Scrub the concrete surface again before pasting fiberglass to ensure no dusts on the paste surface.

Smear the collocated impregnating resin on the paste position evenly with the process stipulation offered by manufacturer. It’s a must to conform to the requirements of stabilization, accuracy and uniformity when brushing structural adhesive on the concrete surface, namely: stabilization means brush with an appropriate force and try not to fall off to the greatest extent; accuracy means the brushing is within the control line; uniformity means an accordant thickness within brushing scope.

3.8 Paste fabrics

1Paste the fabrics on the specified position with hands pressing gently, there’s also needed to be steady, accurate and uniform when pasting the fabrics, and it requires an appropriate force for unwinding so as to make it smooth without crumple, fracture. Use specified roller to roll towards the fiber direction, it’s a must to roll from one side to another side when rolling, and it’s inadvisable to roll and rub at one position back and forth, let the glue permeate into fibers in the rolling to achieve a full inflitration and squeezed-out bubbles so as to make impregnating resin soak into fibers fully, it’s forbidden to damage fibers when rolling. An overall lap length of all directions is greater than 200mm when it’s required to carry out an overlap joint of fabrics..

Repeat the above steps when making a multilayered paste, carry out the following paste process as soon as possible after the impregnating resin on fiber surface being confirmed to be dry with finger touching on glue surface.

Smear impregnating resin evenly on the last fabric surface.

3.9Completion of works: the maintenance time is 48 hours and guard against using sharp instrument scraping and touching fiber surface and pulling by people. In order to facilitate the follow-up underground engineering, carry out a rough sand-scattering processing on fiber surface, subject to be adhesive on figures, during 6-12 hours of fabric paste.

3.10Construction technology measures and quality control points

1 It’s obliged to check and test performance index of factory certification and product quality inspection report of raw material products of fiberglass when entering the construction site.

The concrete surface treatment of base materials is one of the most critical processes for fiber reinforcement construction, and it requires to wipe out floated coat, reveal the concrete structure layer and clear away peeling, loosened, cellular and corrosive faulty concrete on the component surface reinforced. Use epoxy mortar to repair to be smooth, carry out a gap filling or joint sealing treatment in advance if the component is crannied, then polish it smoothly, clean up and keep dry. The interarea is required to be smooth without umbilication and the corners of Yin and Yang shall be sophisticated.

The colloid used for paste fibers shall be collocated in strict accordance with product specification, and the field environmental condition shall conform to the requirements of the product.

Collocate a small amount of adhesion agent each time, it’s forbidden to reuse the remaining and overdue adhesion agent.

The overlapping length of force direction of fibers is not less than 200mm.

In order to ensure that the fiberglass may reliably coordinate with concrete in phase, an additional anchoring method can be adopted.

Fine laying-off, it’s forbidden to employ fiber strips with irregular edge and outer-concave and inner-convexchannel angle.

In the process of pasting fiberglass, there’s a need to roll in place to guarantee the fiber materials are fully impregnated and effectively pasted.

Enhance the inspection and acceptance work of fiberglass paste. The paste quality between fiber and concrete is tested by using a hammer to stroke or pressing the surface of the fiber, and the total effective area is not lower than 95%. Needle-injecting colloid method can be adopted to rectify when the empty drum area is less than 1000m2. When the empty drum area is greater than 1000m2, it’s appropriate to cut off the fiberglass at the position of empty drum and conduct a lap joint again to paste equivalent fiberglass sheet, and the length of lap joint is greater than 100mm.

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