Specialized gravel pit of Put Inženjering d.o.o is located in the flow of the Južna Morava river-extraction place in the village Mezgraja near Niš.

From the upper flow, the river has carried big quantities of gravel and sand, providing for their settlement and creating huge finds of quality mineral raw materials.

Gravel deposits in the flow of the Juzna Morava generally consist of metamorphous rocks crashed parts (63.2%), less quantity of sediment (16,8%), magmatic (4,5%) crashed parts,  as well as mineral grains (15,6%). Gravel quality is characterized by great pureness of natural mixture, good granulation composition, and unpolluted particles and admixtures.

Possibility of use

Based on laboratory test results obtained by INSTITUT ZA PUTEVE A.D of Belgrade –Stone and Stone Aggregates Laboratory, there was specified the application as follows:

1. Natural mixture or sub-base gravel may be used as sub-base layer in the road structure bottom part
2. It may be used in 0/4mm, 8/16mm, 16/32mm fractions for making cement and concrete mixtures to fabricate:
   • cement-concrete (SRPS B.B2010/1986)
   • bottom layer of cement-concrete roadway slab (SRPS U E3.020/1987).
3. Fraction 0/4mm may be used for fabrication of
   • basic mortar layer (SRPS U.M2.010/1992;SRPS U.M2012/1992).
4. Concrete (JUS B.B2.009/1986)