Keywords : compressive strength


Determination of Geotechnical Properties of Local Claystones in Northeast Koya City, Iraqi Kurdistan Region

Nawzat Ismail; Hemn Omar

Iraqi National Journal of Earth Science, 2020, Volume 20, Issue 1, Pages 1-14
DOI: 10.33899/earth.2020.170286

The aim of the current study is to determine the geotechnical properties of the investigated claystones /clayey soils in Koya area, Iraqi Kurdistan Region. This paper deals with the evaluating of the physical, mechanical and index properties of claystones. The study based on the field reconnaissance for twenty-five claystones samples were collected from five outcrops location within Fat'ha Formation. The results obtained from the laboratory tests revealed that the averages of specific gravity, porosity, void ratio, water absorption, natural water content and uniaxial compressive strength values of claystones are (1.5, 4.45%,4.5, 0.3, 3%, 65 MPa) respectively. Whereas the results of the index geotechnical characterization of clayey soils revealed that the averages values of liquid limit, plastic limit, plastic index, flow index, toughness index, liquidity index, consistency index, swelling potential, activity index, and expansive potential are (25.2, 15.0, 10.2, 0.2, 0.5, -1.2, 2.2, 0.62, 0.31, low or non-expansive) respectively. Among the index properties, the clayey soils are suitable for foundation and building materials industry. Furthermore, the regression coefficients of their correlation (R²) obtained from the analysis show that there are strong relationships between the physical and mechanical properties of claystones. Concluding remark is that geotechnical properties of examined natural claystones satisfy the relevant regulation to be used for construction purposes.

Physical Properties and Compressive Strength of the Technical Plaster and Local Juss

Auday M. Al-Rawas; Zeki A. Aljubouri

Iraqi National Journal of Earth Science, 2009, Volume 9, Issue 2, Pages 49-58
DOI: 10.33899/earth.2009.5489

Five physical properties (water/powder ratio, setting time, fineness, porosity and dendsity) and compressive strength were determined and compared for technical plaster and local juss.Data were monitored using a standard dental stone. The relationships between these properties were also studied. It was revealed that local juss has inferior properties compared with technical plaster. It has lower compressive strength; higher water/powder ratio; shorter setting time; larger grain size and higher porosity. There is an inverse relationship between compressive strength and the two properties water/powder ratio and porosity. There is a direct relationship between compressive strength and the two properties particle size and density. There is also a direct relationship between setting time and the two properties particle size and water/powder ratio.