Stehr - Manhole Cutter
Your professional tool for use in
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Surface repaving and repair
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New road construction
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Restoration of embedded assemblies
Prior to repaving and repairing the surface, the embedded assemblies are ground free. At least 15 such assemblies can be freed in one hour's time. Then the asphalt grinder can remove the surface without encountering any obstacles. Work then continues as for new construction.
A dummy cover is laid over the shaft during new construction and the roadway is completely paved over and compacted. Then the (previously surveyed) embedded assemblies are ground free. The advantage: Optimal compaction around the edges of the shaft.
For the restoration of embedded pre-cast assemblies, one grinding is used to cut the old shaft frame free and open up enough room to emplace the new element. The cutter head's size and configuration are geared to the type of restoration being made.
Grinding time is about two minutes per shaft. The hard-metall grinder chisel has a very long service life that averages 100 bores, and it can be replaced quickly and economically.
Grinding During Restoration and Repaving Work
Grinding During Restoration and Repaving Work
Up till now:
Embedded assemblies (e.g. inspection shafts), which needed to be restored or repaired due to frost damage, settling or the results of extreme traffic, had to be cut free and chiseled out in tiresome and expensive manual labor. It took several hours to restore one single inspection shaft - the costs were accordingly high and the obstruction to traffic enormous.
Manual labour
The milling machine leaves a square area ungrinded.
Grinding or Cutting?
Additional damage is foreseeable even when using the process, whereby shaft sleeves are cut open using a diamond cutter head:
a) Quality
The diamond head's vertical cutting edges are too smooth to ensure a good joining. A predetermined break point is unavoidable. On the other hand, Stehr's somewhat rough grinder edge causes the materials to mesh effectively and creates a permanent joint and bond.
The diamond head's vertical cutting edges are too smooth to ensure a good joining. A predetermined break point is unavoidable. On the other hand, Stehr's somewhat rough grinder edge causes the materials to mesh effectively and creates a permanent joint and bond.
b) Costs
Unlike the Stehr cutters, tool costs are extremely high - a diamond cutter head can be extremely expensive! And the head might be totally destroyed the first time it's used should it come in contact with a gravel foundation. The tool costs for a Stehr grinder head are about 50 Euro. According to our users, the grinder chisel has a service life of some 50 to 100 bores, resulting in tool costs of a maximum 1 Euro per bore!
Unlike the Stehr cutters, tool costs are extremely high - a diamond cutter head can be extremely expensive! And the head might be totally destroyed the first time it's used should it come in contact with a gravel foundation. The tool costs for a Stehr grinder head are about 50 Euro. According to our users, the grinder chisel has a service life of some 50 to 100 bores, resulting in tool costs of a maximum 1 Euro per bore!
c) Cooling
Our cutter requires no water cooling, whereas the diamond-cutter-head system does. The resulting emulsion, produced from cutting asphalt and tar with water, contains large amounts of hydrocarbons. Environmental contamination could result if this emulsion finds its way into the sewage system or ground water. Lots of water has to be used after each cut to wash the unnecessarily dirtied roadway. According to the manufacturer, 60 liters (15.9 gals) of water are needed for each cutting operation. Not to mention the 500 liters (132.1 gals) you'll need just to clean the street.
Our cutter requires no water cooling, whereas the diamond-cutter-head system does. The resulting emulsion, produced from cutting asphalt and tar with water, contains large amounts of hydrocarbons. Environmental contamination could result if this emulsion finds its way into the sewage system or ground water. Lots of water has to be used after each cut to wash the unnecessarily dirtied roadway. According to the manufacturer, 60 liters (15.9 gals) of water are needed for each cutting operation. Not to mention the 500 liters (132.1 gals) you'll need just to clean the street.
Side grinders are available in high, middle or low position.
Flat or conical shape.
Lay a circular template over the manhole cover and then spray marker paint around its
outer edge.
outer edge.
Position the Stehr cutter exactly over the center and press it firmly into place using its
carrier unit. The same principle applies when using the circular template for all other
embedded elements.
carrier unit. The same principle applies when using the circular template for all other
embedded elements.
Grinding operations can now begin. Cutting time ranges from 1 to 5 minutes.
Appropriate hydraulic power of the vehicle prerequisted.
We are happy to assist you with any questions you might have regarding optimal cutting
diameters. Critical factors include:
diameters. Critical factors include:
- Dimensions of the embedded assemblies
- Current stage or progress of construction
- Size of the carrier plates for utility valves and hydrants
Additional Information:
Summary
The use of machines to work on shafts, utility valves and hydrants during new road construction and restoration is decisively more economical and produces greater quality than the more costly manual labor. Not to mention how much faster the work can be accomplished. This type of machinery provides you with a real opportunity, especially in those areas where aggressive pricing places a burden on your margins. Rethink your direction and move forward with Stehr specialized machinery.
