In the earthworks sector for building of engineering objects (road embankments, railway embankments, flood banks, earth water dams, waste disposals constructions and sealing elements, soil replacements, and other) there are used natural and anthropogenic raw materials. Such raw materials are defined as: soils, earth masses for building, rock material in the literature of building area and in the Polish and European standards. Earth masses are used in a native state (raw, natural) or after improvement. Regarding their origin there are the following materials distinguished:
- local raw materials, earth masses (native soils, anthropogenic soils) coming from a construction site, digging or spoil accumulated during the previous earthworks – these materials are used for building in the first place;
- raw materials coming from outer sources (in the case of a local raw material shortage):
- earth masses delivered from outside the construction site e.g. raw materials exploited from sand and gravel deposits, dimension and crushed stones deposits or raw materials for engineering works deposits,
- anthropogenic soils: artificial aggregates, mining wastes, industrial wastes
Data presented below, regarding resources and output, are related only to deposits classified as the deposits of raw materials for engineering works, which were documented according to the Geological and Mining Law regulations and which are intended for exploitation in the case of a local raw material shortage (on a construction site). On a national scale, these deposits supply only a part of the raw material used in the earthworks sector. The majority of a raw material comes from other sources, including deposits classified as “sand and gravel” or “dimension and crushed stones”.
The Geological and Mining Law does not define the limit values of the parameters that defines the deposit of this type of a raw material – the raw material is not listed in the Regulation of the Minister of the Environment of the 1st of July 2015 on the geological documentation of a raw material deposit, excluding a hydrocarbon field (Journal of Laws 2015, Item 987). The usefulness assessment and determining deposit boundaries are based on balancing criteria established by an investor and on regulations concerning building and contracting of earthworks – these regulations concern the quality parameters of a rock material and the technical parameters of projected structure. The scope of tests depends on the raw material type and is predicted use.
Deposits of raw materials for engineering works are often documented for the needs of a particular investment. After its ending, the resources of unused raw material (often useless for other purposes) are crossed out from the registry, and the area is allocated to the purposes not connected with deposits exploitation.
The list of natural raw materials (soils, rocks) of a characteristics allowing to using them directly or after improvement to an earth building construction is very long. It contains i.a.: fragmented hard rock soils and rocky soils; mantle rock soils; rubble and pebbles; sands, gravel and sand-gravel (including: loamy and silty types); loamy sands with an admixture of gravel-rocky fraction (morainal); sandy silts and silts; fragmented soft rock soils; mantle rocks and loamy rubbles, etc. The raw material availability is practically unlimited throughout the country.
There are usually clastic rocks of a clayey-sandy characteristics documented e.g.: silty sands (not meeting the criteria for sand and gravel deposits), mantle rocks, loamy-clayey sediments, but also compact rocks: sandstones, limestones, conglomerates – parts useless for the production of crushed aggregates, allocated from dimension and crushed stones deposits. Typically, the raw materials for engineering works are an accompanying raw material in sand and gravel deposits or dimension and crushed stones deposits. They constitute a main raw material in about &frac13 cases.
Resources and output
The total anticipated economic resources amount to 17.200 million m3. In comparison with 2020 they decreased by 0.056 million m3 (0.3%).
In 2021, there were three new documentations with recalculated resources (supplements) elaborated:
- in Opolskie Voivodeship, below the current boundary of the sand deposit Zawada 1 there were 0.312 million m3 of the Pliocene clays documented – useful to hydro-technical embankments building;
- in Mazowieckie Voivodeship there was the Sukowska Wola deposit crossed out from the registry with the resources equal 0.050 million m3 (about 0.085 million tonnes) – on the basis of a decision approving a new documentation with recalculated resources (supplement) of a settlement type. The raw material was used only for the road embankments building of the Radom ring road – the investment was ended;
- in Lubelskie Voivodeship there was the Zalesie deposit crossed out from the registry (0.024 million m3 of loam – the accompanying raw material in the sand and gravel deposit). The exploitation of the given deposit has not been undertaken. The resources of loam had not been included in “The balance…”.
The table given below shows the current state of identification and management of mineral raw materials for engineering works resources in Poland.
The output of mineral raw materials for engineering works amounted to 0.301 million m3 in 2021 increasing by 0.058 million3 (23.9%) in comparison with the previous year. There were 12 deposits under exploitation. There were also 0.030 million m3 of loams and schists extracted from the building ceramics raw materials Biecz 1 deposit in Małopolskie Voivodeship, and the raw material was used for flood banks and embankments building. The production of building ceramics based on this deposit was permanently abandoned.
The economic resources were calculated for 13 deposits. They amount to 6.059 million m3 in total. These resources decreased by 0.305 million m3 (4.8%) in comparison with 2020.
The figure given below shows changes in domestic resources and production of mineral raw materials for engineering works in Poland in the years 2000-2021.