CUTTING GREEN CONCRETE WET CONCRETE

Many popular floor saws turn counter-clockwise, also referred to as up-cut rotation. It pushes the concrete to the surface as it cuts and then the skid plate helps to trowel the edge smooth. Technically, this method disturbs the aggregate by nudging it upwards, but all is smoothed over by the skid. The cuts look perfect upon completion, but the edges have been disturbed by the up-cut process. Some fail after they’ve cured with heavy traffic, but the contractor gets paid at the time the job is done. A down cut rotation is always preferred as it does not kick up the aggregate and loosen the joint… BlogGraphic2 See how the top edges of the joint are no longer straight? Picture the saw blade rotation and how it can push the aggregate up and loosen the concrete around the joint. The SG10 cuts downward and does not kick up aggregate, solving this issue. So why can’t you just use a regular down cut saw to cut soft concrete? It takes a very precise saw to cut green concrete cleanly. Most conventional saws allow too much movement both laterally and vertically. Larger diameter blades have more chance of wobble which can also damage the cut. The SG10 uses a 10” blade maximum and can also use as small as 7”. The key to cutting clean is speed and control and that’s where the SG10 comes in. BlogGraphic4 BlogGraphic3 Notice the distance of vertical travel (blade raising and lowering) is minimal on the SG10 as compared with a conventional flat saw. What makes the SG10 great for cutting green concrete? Vertical travel – Notice the distance of vertical travel (blade raising and lowering) is minimal on the SG10 as compared with a conventional flat saw. The lower profile and shorter distance of travel keeps the weight forward and down on the blade. This helps control side to side movement which on its own, is enough to spall a joint. Wheel tracking – The SG10 has four of the same size wheels in parallel; both side to side and front to back. This helps keep a straight true cutting path. Blade position – The SG10 has a center mounted blade, where most saws use side mounted blades. The side mounted blade acts as a point of resistance and makes the saw want to steer in that same direction. This makes it difficult to cut a straight line which is critical. A saw with a center mounted blade wants to cut straight. Debris – A side mounted blade will throw the debris under the outboard rear wheel and can make the saw teeter over the debris. The teetering can disturb the joint. The SG10 throws the debris back between the wheels leaving a smooth surface to ride on. Blade Speed – Most other 10” saws will turn at between 3,000 and 3,600 rpm. The SG10 spins at 6,000 rpm. The higher speed allows the blade to slice through the concrete and aggregate without disturbing it as a low rpm saw will do. Tracking Control – Just as in the front, the SG10 has a rear pointer with a narrow disc that drops down in to the existing cut. This feature keeps the saw tracking straight and true.

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