Steel Plate Bonding

SHO-BOND STEEL PLATE BONDING METHOD In this method, steel plates are bonded to the tensile surface of existing slabs to integrate the steel plates with the existing concrete. The SHO-BOND STEEL PLATE BONDING METHOD consists of the two kinds described below. (1) INJECTION METHOD This is the method in which SHO-BOND GROUT is injected into that gap, with an average gap of 5mm set up between the slab surface and steel plate. ■ Detailed Sectional Drawing ■ Detailed Drawing of Plate Holes FEATURES 1. The load-bearing force is increased by bonding to the tension side of the slab, steel plates that play a role equivalent to that played by reinforcing bars. 2. Because of the strong bonding force the adhesive materials possess plus the fact that they do not contain any volatile solvent, there is no hardening shrinkage. 3. Permits work to be executed with the bridge opened to traffic. REINFORCED EFFECTS Test results obtained with actual bridges are given below. Details of test: Comparison of generated stress intensities for before and after reinforcement using wide steel plates. Measuring position: At tension bars and bonded steel plates located at center point of slab span. VEHICULAR LOADING WEIGHT Total Weight (kg) Front Wheel Weight (kg) Rear Wheel Weight (kg) Before reinforcement 20,000 4,750 15,250 After reinforcement 20,100 4,750 15,900 SHO-BOND STEEL PLATE BONDING METHOD The respective generated stress intensities for before and after reinforcement are as listed below. TEST RESULTS Before reinforcement Reinforcing bar 1-direction 2-direction 409 252 Steel plate 1-direction 2-direction 141 66 After reinforcement (kg/cm²) 66 73 Ratio of stress dissipated due to reinforced effects (%) 83.9 91.2 Note: The above values are average measured values obtained by taking a total of nine measurements (3 sets of 3 locations) and averaging them. WIDE PLATES Used for the purpose of reinforcing the slab both in the main reinforcing bar direction and distribution bar direction. NARROW PLATES Narrow plates are used when there is an apparent lack in the amount of reinforcing bars in either the main reinforcing bar direction or distribution bar direction, in comparison with the generated stress intensity, and when it may be judged so from the structural condition. The plates are bonded in the direction where there is a shortage of reinforcements. In other words, reinforcement is performed only for one direction. SHO-BOND STEEL PLATE BONDING METHOD WORK METHOD PRELIMINARY TREATMENT (Plateworking) 1. Treat the surface of the steel plate so as to bring out its texture. 2. Drill such holes as anchor holes and work the steel plate to the desired dimensions. (Slab Preparation) 1. Scrape the surface of the concrete slab with a disc sander, or the like, and level the surface irregularities using SHO-BOND #101. 2. Install anchors for anchor bolts into the slab. INJECTION METHOD 1. After confirming that pretreatment both for the steel plate and slab has been properly executed, proceed to the following work. 2. Clean the plate surface using SHO-BOND THINNER. 3. Attach the injection pipes and air vent pipes. 4. Fit on the steel plate and clamp it with anchor bolts. 5. Using SHO-BOND #101, seal the peripheral area of the steel plate as well as the area surrounding the injection holes. 6. Inject SHO-BOND GROUT through the injection holes. 7. Upon completion of curing, paint the area. PRESSURE ATTACHING METHOD 1. After confirming that pretreatment both for the steel plate and slab has been properly executed, proceed to the following work. 2. Clean the plate surface using SHO-BOND THINNER. 3. Apply SHO-BOND CS to the plate surface and concrete surface. 4. Pressure-attach the steel plate to the slab using anchor bolts, etc. 5. When the material has cured, withdraw the pressure attaching equipment and paint the area.