Continuous operation with concrete and construction rubble
Plenty of steel and lots of 0/45
Small percentage of sand and equal distribution of grain
During intensive continuous operation the CST 500 has been put to the acid test. Feed material consisting of basalt, concrete with reinforcement bars as well as manhole covers and bucket teeth was given to the crusher. It may be a miracle that there was no damage of the machine, however, we are convinced that the damages were avoided because the CST series was developed for heavy duty purpose and offers technical solutions to prevent machine damages.
The throughput performance of the CST 500 was strongly dependent on the size of the fed pieces. With a constant feed of material of <300 mm a performance of 100 t/h and more was achieved.
The fact that the demands for an optimum form of grain and low percentage of sand are fulfilled as well is the result of intense development work.
If the sand percentage included in the feed material is again added to the crushing material the demands for anti-frost and gravel-bearing layer according to TL SoB-StB 04 are fulfilled.
The grading curve established can be downloaded here.
Evaluation of the crushing material by means of a sieving analysis has shown that there is a homogenous and equal distribution of grain. The percentage of sand is very low which means that the sand percentage of the supply and pulverization can be added. Distribution of grain according to the Guideline TL SoB-StB 04 for RCL Material is produced thus creating outstanding features with regard to load capacity and compressibility.
An equal grain distribution, however, is crucial for a high load capacity of the RCL gravel. This way it is ensured that a supporting structure is created in the base course. Good compressibility of the material means that this supporting structure could be created between the grains. If the sand percentage is too high this means that larger grains lose contact with each other, thus producing more movement of the coarse grain. Here’s a citation by a local building contractor: „Initial experiences with frost protection 0/45 have proven to be all positive. The frost protection material created by means of the CST 500 can perfectly be compressed. The solidity of the insertion layer exceeds by far any other construction material used up to now! An excellent alternative for gravel from local stone production."
Concrete and building rubble often contain foreign material of metal like reinforcing bars. The CST series was able to separate 99% of those elements without being damaged. The crushing tools and the entire drive are made for this purpose. Applying a large twisting moment the concrete is crushed and the bars are exposed. Steel bars of up to a diameter of 20 mm are no problem. In case of overload caused by oversized steel bodies the hydraulically adjustable roll releases the crushing gap and automatically returns into working position. Blockage is managed independently by means of automated reverse operation.
Even excavating teeth or complete metal plates do not lead to damage of machines or tools even if the crusher is forced into the blockage at full speed. After several repeated starts of the crusher an information is given to the operator or the foreign material is just "spit out" by automatic release of the crushing roll thus releasing the foreign body.