Assessment of carbonate rocks for engineering applications considering mineralogical, geochemical and geotechnical attributes

Due to continuous need of materials for infrastructural development, geomaterials of different origins are used where available. Vast majority of these materials in some countries are predominantly metamorphic and sedimentary in nature. Many of these rocks are of carbonate origin and they are encountered by practitioners worldwide. Therefore, it is very crucial to evaluate the prospect of using carbonate rocks for different applications. In this paper, laboratory tests were conducted on soft and hard carbonate rocks in order to assess their usefulness taking into consideration the mineralogy, geochemistry and geotechnics. The mineralogy is majorly calcite, the fabric is characterized by aggregation of particles to form clusters and the chemical composition is predominantly calcium oxide. The hard carbonate rocks have low porosity, medium dynamic fragmentation, medium to low water absorption, slightly strong rebound hardness value, high uniaxial compressive strength and soft carbonate rocks have low in situ specific volume and compressibility. The carbonate rocks are suitable for cement production. The hard carbonate rocks can be used for infrastructure purposes. The soft carbonate rocks are suitable for use as foundation fill materials and suitable for use as sub-grade materials. However, practitioners must be cautious when using this material as sub-base materials.