Demolition of a bridge in Leeuwarden
Hydraram demolition tools make short measurements with the “Drachtsterbrug” in Leeuwarden.
Begin of September, Van der Wal Sloopwerken from Joure started the demolition of the old Drachtsterbrug in Leeuwarden. To make the big deal, this Frisian demolition contract is making a great deal of equipment. The demolition of the bridge deck, the pillars and the associated landings requires heavy machinery and, in addition, there is a considerable amount of time pressure on the project. The old bridge and viaducts can finally be gone when the new aqueduct is ready. For suitable demolition tools Van der Wal joined Peter Wassenaar of Hydraram in Surhuisterveen. In addition to the sale of Hydraram accessories, Hydraram has a very diverse fleet of demolition tools. It also includes the power of this Frisian company as well. Customers can temporarily rent, so that they get an impression of the capacity and eventually decide to purchase.
However, fittings can also be rented on a project basis for a short period of time. Hydraram has temporarily rented a FX-460 Pro hydraulic hammer, MK-20 multichair, HCC-85V concrete scissor and HRP-72V rotary grinder to Van der Wal. The FX-460 Pro weights 3.2 tons and is deployed to its own Doosan DX380. The hammer is suitable for machines in the weight range of 34 to 50 tons and requires between 190 and 280 bar of working pressure. For optimal lubrication of the chisel bushes and to prevent unnecessary wear, this Hydraram is equipped with automatic grease lubrication. This gives the hammer the right amount of fat. This ultimately saves on maintenance costs. Of course, the operator must keep an eye on whether the fat pattern is almost empty. For the crushing of the bridge and viaducts, a rigid HFP-25V crushing machine is used. It weights 2,450 kg and demands 350 liters of oil per minute. This at a working pressure of 350 bar. The crusher is suitable for machines between 25 and 32 tons and has an jawopening of 852 mm. On the inside of the mouth are knives to cut concrete iron. The maximum power at full opening is 85 tonnes.
A major advantage of rigid crushers is that they are fitted with two changeable teeth on the fixed jaw. This allows the concrete to "rake" and thus remove more concrete iron between the debris, which causes more iron yield. Because of the use of changeable teeth, maintenance costs are low and the rest stops to a minimum. There is no need to be worn and so little heat has to be introduced. This also improves the life of the crusher. This is also used by the own crane, just like the MK-20 multiprocessor, which is fitted with a crushing jig. There can also be chosen for example a steel jug, cutter blade, plate jug and wide jaw. The base yoke weights 1.465 kg and the crush is 1.010 kg. Before cutting, the multiprocessor requires between 200 and 300 l/min and this at a working pressure of 310 bar. The rotation requires 10 l/min and the maximum operating pressure is then 140 bar.
A major advantage of the MK-20 is that it is possible to perform all common demolition work with only one equipment. Depending on the nature of the demolition cycle, one can choose which pelvis one wants to take. Usually customers choose a pinch, a crutch and a steel jug.
The Hydraram HCC-85V concrete scissor is used for the large joints of the bridge and viaducts. This depends on the hired Cat 385C. The scissor weighs approximately 8.5 tons and has a maximum opening of 1,830 mm. The maximum cutting force at the tip of the teeth is no less than 185 tons! On the inside, the concrete scissors have cutters to cut concrete steel. Here's the cutting power at 720 tons. The HCC-85V is a great size for the 90-toner. Often companies want heavier scissors because there is a need for greater closure. But then there's hardly any work and the machine starts to flip. This is bad for both the bowl and the excavator arm. One still has the capacity to tackle cut and cut concrete pieces. Often the priority is to cut as quickly as possible and get down from constructions. In order to be able to work further, the crane must be able to put a bit of effort, as the concrete has not been crushed. That is no different on the project of the `Drachtsterbrug`. The opening and closing of the big concrete scissors requires around 3.9 seconds. Therefore, a very large Hydraram HRP-72V is used for the many crushing work. It will certainly come true. In the heavy concrete slats, the deck and pillars are quite a bit of reinforcement steel. By cutting with a large scissor, a box is fast downstairs and should be cleaned immediately. One can then proceed with the removal of debris as soon as possible and the paws can be demolished.
The use of scissors is requested to limit noise for the inhabitants. This makes the use of the large Hydraram HCC-85C concrete scissors excellent. Even with the HRP-72V one can still cut well. This is due to the large opening of the crusher in this weight class. The teeth are also placed in such a way - especially those on the front of the movable jaw - that the concrete is tightly clamped. This allows the crusher to work as a "scissors". However, this is made to ferment. The HRP-72V has a weight of 7.250 kg and is suitable for 68 to 85 ton excavators. He therefore fits the Cat 374D perfectly. The crusher requires opening and closing between 450 and 600 l / min and a working pressure of 340 bar. Rotation requires 30 l/min and a working pressure of 140 bar. The maximum clearance measures 1.320 mm and the cutting force is 180 ton. The width of the crush is 790 mm. Here too, the manufacturer chooses for knives on the inside. Opening the crusher requires 3 seconds time, closing 3.7 sec.