AGOM EXPANSION JOINTS INSTALLATION PROCEDURE

Transcription

1 AGOM EXPANSION JOINTS INSTALLATION PROCEDURE

2 HOW TO REALIZE A JOINT LINE When you have to realize a joint line, workers have to install many units jointed together with a groove-and-tongue junction welded with special glue. Actually the AGOM expansion joints type AGWJ and AGFLEXJ are supplied in two meters long elements with the exception of the AGFLEXJ 330 that is one meter long. The joint fixing is obtained by chemical anchors. The nuts are locked using a dynamometric key so that a permanent compression strength is given to the joint. In that way the horizontal forces, due to braking of vehicles and to the reaction that rubber oppose to the joint deformation (shrinkage, flu age, thermal variations etc.) are transmitted by friction between the rubber and the concrete. AGOM expansion joint can be installed also on a metallic infrastructure. AGOM EXPANSION JOINT JOINT MOVEMENT DIMENSION A x H x L DISTANCE P WEIGHT [Kg/m] AGWJ 50 ± x35x AGWJ 70 ± x35x AGFLEXJ 30 ± x32x AGFLEXJ 50 ± x42x AGFLEXJ 80 ± x46x AGFLEXJ 100 ± x53x AGFLEXJ 140 ± x78x AGFLEXJ 160 ± x82x AGFLEXJ 200 ± X70X AGFLEXJ 250 ± x78x AGFLEXJ 330 ± x100x Pag 2

3 EXPANSION JOINT TYPE AGWJ EXPANSION JOINT TYPE AGFLEXJ AGFLEXJ AGFLEXJ INSTALLATION PROCESS FOR AGOM EXPANSION JOINTS Before installing an expansion joint is very important to make sure of the bridge movements (see general rules to calculate bridge movement pag. 7) and to check the asphalt thickness in order to verify if the chosen type of joint can be correctly installed and what is the better type of installation. There are mainly two type of installation, one of which suitable for little expansion joint and the other for bigger one. Layout a ground plan for the joint and mark the cut width at both side of the axis. Using a diamond disc cutting machine, cut and remove the asphalt to obtain the recess of the enquired width and depth for each respective AGOM expansion joint type. Pag 3

4 TYPE 1 - INSTALLATION FOR LITTLE EXPANSION JOINTS For little expansion joints like AGOM AGWJ and AGFLEXJ the installation type 1 is suggested. W 1 A H S If S>30 mm use levelling mortar If S < 30 mm use levelling epoxy resin G I 1. After demolition and leaning of the slab, the steel reinforces will be prepared and the levels verified. 2. The gap will be protected with a polystyrene piece and the modules of expansion joint will be centred on the structural joint applying polyurethane sealant or the epoxy bedding at the tongue & grove interface before installing the adjoining element in order to achieve a waterproof connection. 3. The points where the anchoring are to be placed will be marked and drilled. The holes will be flushed thoroughly with compressed air and will be filled with a fast curing pour able epoxy grout before to insert the anchor bolts vertically down. After that Workers will start the casting of the mortar. 4. Once the mortar is set and the protection removed, washers and nuts will be located on the bolts. Nuts will be adjusted with the appropriate tightening torque using a dynamometric key. Epoxy sealant product will be used to fill all the bolt hole cavities. Pag 4

5 TYPE 2 - INSTALLATION FOR AGOM EXPANSION JOINTS For all type of expansion joints and particularly for bigger expansion joints, the installation type 2 is suggested. W2 A H S G if S > 30mm use levelling mortar if S < 30mm use levelling epoxy resin I SEAT JOINT HEIGHT [H] WIDTH [W 1 ] [W 2 ] GAP [G] DISTANCE [I] AGWJ AGWJ AGFLEXJ AGFLEXJ AGFLEXJ AGFLEXJ AGFLEXJ AGFLEXJ AGFLEXJ AGFLEXJ AGFLEXJ Pag 5

6 1. After demolition and leaning of the slab, the gap will be protected with a polystyrene piece and the levelling mortar will be applied to form a layer of level bedding for the expansion joint. 2. Once the mortar is set, the modules of expansion joint will be centred on the structural joint and the points where the anchoring are to be placed will be marked. Then the modules will be removed and the holes will be flushed thoroughly with compressed air. JOINT ANCHOR material: C40 zinc plated [M x B] HOLE Ø DEPTHT AGWJ 50 M12 x 190 ø AGWJ 70 M12 x 190 ø AGFLEXJ 30 M12 x 190 ø AGFLEXJ 50 M12 x 190 ø AGFLEXJ 80 M14 x 200 ø AGFLEXJ 100 M16 x 200 ø AGFLEXJ 140 M16 x 200 ø AGFLEXJ 160 M16 x 200 ø AGFLEXJ 200 M20 x 230 ø AGFLEXJ 250 M20 x 230 ø AGFLEXJ 330 M24 x 300 ø The holes will be filled with a fast curing pour able epoxy grout before to insert the anchor bolts vertically down. 4. When the anchoring is hardened, Workers will start laying the first AGOM expansion joint element applying polyurethane sealant on the epoxy bedding at the tongue & grove interface before installing the adjoining element in order to achieve a waterproof connection. Pag 6

7 5. Modules will be aligned and washers and nuts will be located on the bolts. Nuts will be adjusted with the appropriate tightening torque using a dynamometric key. Epoxy sealant product will be used to fill all the bolt hole cavities. 6. Transition strips: Be sure that the asphalt walls and the module walls are completely clean and dry. After that workers will prime carefully the asphalt walls, the module walls and the bottom surfaces of the two side gaps by using a brush or a roller. Before the priming will be cured, they will prepare and apply the epoxy based product by mixing properly the epoxy resin with siliceous arid. The epoxy resin will be applied by using a shovel (previously wet in solvent) in order to make easier the application. The resin must be very well levelled in relation to the module and the asphalt. 7. Once the mortar cured, transition strips will be painted with pure resin. In order to accomplish a clean finish, a paper tape should be placed along the edges of the joint and all along the asphalt before painting the transitions. Those tapes will be removed once this task is finished. GENERAL RULES TO CALCOLATE THE BRIDGE MOVEMENT The movements to be considered for the expansion joints, arise from the following causes : Thermal expansion and contraction of the superstructure and in certain cases even of substructure Shrinkage of concrete Creep in the concrete Elastic shortening under prestress Displacement of the structure under load, temperature variations or any other action. Because expansion joints are installed at a late stage in construction, therefore, some of these movements will already at least partly have been taken place. Hence less total movement has to be considered for the expansion joints than for the bearings at the same location. It s possible to calculate the maximum opening movement of the expansion joint by adding all the irreversible and reversible movements due to concrete retraction and creep, thermal movements and elastomeric bridge bearings deformation. At the same way it s possible calculate the maximum closing movement of the expansion joint by adding the thermal movement and the displacement of the structure under load or any other action. Pag 7

8 A) Irreversible movements Concrete retraction: Regardless of the factors that should be taken into account, such as degree of ambient humidity, piece thickness, concrete composition, typical strength, number of reinforcements and diameters, etc, an approximate value of 0,25 mm. per metre is taken, with the correction corresponding to the elapsed time since the piece concreting and joint installation (100% in 2.5 years). Concrete creep: Regardless of the factors that should be taken into account, such as degree of ambient humidity, piece thickness, concrete composition, typical strength, number of reinforcements and diameters, etc, an approximate average value of 0,20 mm. per metre is taken, with the corresponding correction (100% in 10 years). B) Reversible movements Thermal expansion and contraction: Maximum and minimum temperatures of the structure location area have to be considered, as well as the assembling temperature and its structure and thickness. The approximate average value o thermal expansion/contraction is 0.01 mm. per metre and degree of centesimal temperature. Pag 8

9 where the correction factor K H is related with the thickness and the type of structure SOLID SLABS VOILED SLABS CAISSON SLABS THICKNESS K H THICKNESS K H THICKNESS K H 0,30m 1,15 0,60m 1,09 1,67m 1,06 0,60m 1,00 0,90m 1,05 2,22m 1,00 0,90m 0,97 1,20m 1,02 2,78m 0,97 1,20m 0,95 1,50m 1,00 3,33m 0,95 The displacement of the structure under load or any other action. For this example let's consider only the movement due to elastomeric bridge bearings under a maximum horizontal force of 18,000 kg, which deforms all the elastomeric bearings upon which the structure rests, and instantaneous deflection factor G = 14 Kg/cm2 Pag 9