Study On The Cutting For Ceandbead Wear Of Concrete Sawing With Diamond Wire

As a common modern engineering structure building materials, concrete is widely used in buildings, bridges, tunnels, airport and mine. With the wide application of concrete, concrete cutting has become a huge industry. Especially after the Second World War, the countries all over the world have invested hugely in construction industry which causes the development of concrete sawing technology. Sawing the concrete with diamond wire is a new technology of diamond tools. The diamond wire saw can adjust the cutting direction and the wire length according to the work condition, therefore the sawing depth is unlimited. Some very large concrete structures dismantle and some concrete in the special environment can be sawed easily with this new technology. So there is a good application area for the wire sawing. Compared with the concrete sawing with circular blade sawing, the research on the concrete sawing with diamond wire is not reported widely.In this paper, the plain concrete and reinforced concrete was studied with the sintering diamond wire. Firstly, the effect of machining parameters, sawing length and concrete structure on the sawing force were studied. Then, the wear of diamond bead with the machining process was studied. The main conclusion is as follows:1. Sawing force increased with the increase of feed rate and the decrease of wheel speed. The increase of sawing length also improved the sawing force. Empirical formula shows that the sawing length and feed rate had positive influence on the sawing force. Wheel speed has most important influence in the sawing force, but it is negative influence.2. The addition of rebar has little effect on the sawing force in the whole sawing process. However, the sawing force would be increased when the wire touch with the rebar.3. The diameter of the diamond beads were smooth wear when it through the strong wear in the initial stage. The wear in the front of bead is faster than it in the middle and end of bead. The whole bead likes a taper when it enters the steady wear stage.4. After dressing, the protrusion of diamond grit on the bead surface is about80um, about20%of the diamond grit diameter. The protrusion of diamond grit decreases to60μm after some sawing process.5. The wear of diamond grit can be divided as emerge, whole, polishing, micro-fracture, macro-fracture and pull-out. The morphology rate of emerge, whole and micro-fracture decreased rapidly with the machining process. However, the morphology rate of macro-fracture ad pull-out increased rapidly at the same time. The rate of polishing is not change obviously.6. When the diamond wire cut concrete, there are many wear method for the diamond grits. The ideal wear process for the diamond grit is whole-polishing micro-fracture-macro-fracture-pull-out. Unfortunately, many diamond grits wear abnormal.This thesis results will provide the reference to how to saw the concrete with diamond wire reasonably and how to develop the new diamond wire production using to sawing concrete.