JJEES Jordan Journal of Earth and Environmental Sciences Geotechnical Evaluation of South Jordan Basaltic Rocks for Engineering Uses Suhail Sharadqah 1 , Reyad A. Al Dwairi 1* , Mazen Amaireh 1 , Hani Nawafeh 2 , Omar Khashman 3 , Aiman E. Al-Rawajfeh 1 ,Soraya M. Perez 1 Abstract 1. Introduction Basalt is one of the most common igneous rocks in the world. It is a crystalline basic igneous volcanic black rock which is sometimes glassy. Basalt is widespread in seafloor crust, oceanic islands, continental volcanoes, and flood plateau lavas. It is primarily recognized by its dark color. Mineralogically, it is composed of the following main primary rock forming minerals: Plagioclase, Feldspar, Pyroxene, and Olivine. Basalt-based materials are environmentally friendly and not hazardous and can be utilized in many industrial applications. The applications are based on the basic quality properties such as high abrasion resistance, compressive strength, and chemical resistance. Basaltic rocks are used extensively as engineering materials including aggregates for Portland cement concrete and asphaltic concrete, and rock fill for dams and breakwaters. It can be utilized also as material for railroad ballast and highway base courses (Goodman, 1993). The main objective of the present study is to assess the general suitability of the basalt as a coarse aggregate for concrete mixes and/or as a cut stone for industrial uses. The quality properties of the basaltic rocks vary from Keywords: Basalt, South Jordan, Geotechnical, Building stones, Engineering properties. 1 Tafila Technical University, Faculty of Engineering, Natural Resources and Chemical Engineering Department, Jordan. 2 Al-Hussein Bin Talal University, Faculty of Engineering, Mining and Minerals Engineering Department, Ma’an, Jordan. 3 Al-Hussein Bin Talal University, Faculty of Engineering, Environmental Engineering Department, Ma’an, Jordan. Jordanian basaltic rocks (JB) are highly distributed and available in huge quantities in northeastern, central, and southern Jordan. The objective of this study is to determine the geotechnical properties and those relevant to engineering of JB from southern Jordan, which is related to the Tertiary- Quaternary continental basaltic flows and to conduct a comparison of the results with the standard specifications. Ten random samples of southern Jordan basalt (SJB), were collected representing ten locations. The laboratory investigation included measurements of point load strength, splitting tensile strength (MPa), Los Angeles, abrasion value (%), slake durability, abrasion, porosity, and saturation degree. In addition, the chemical and mineralogical composition of the basalt was identified utilizing X-ray fluorescence (XRF), and X Ray Diffraction respectively. The X- Rays show that the studied basalt is mainly composed of clinopyroxene, plagioclase and feldspar; also, olivine is available in significant amounts. Iron oxides (magnetite and ilmenite), iron-titanium oxides (Titanium-augite, sphene) and spinel are present in relatively minor amounts In terms of the SiO 2 contents, the samples from the SJB range from about 41.08% to 46.2%, while the Al 2 O 3 % values range from about 11.95% to 14.25%. The Fe 2 O 3 % values range from 2.3% to 5.22 % and FeO% from about 0.12 % to 0.16 %. MnO% values range from 0.12 % to 0.16%, MgO% from 8.71 % to 10.1%, CaO%, from 9.95 % to 12.05%, Na 2 O% from 2.18% to 3.9%, K 2 O% from 0.1% to 1.16%, and TiO 2 % from 2.35 % to 2.9%. In general, SiO 2 contents are relatively low (< 50%); accordingly, the potential for alkali silica reaction (ASR) is very low. The results of properties related to engineering indicate that SJB has compressive strength values ranging from 96 to 154 Mpa. Los Angles Abrasion ranges between 3.68% and 4.85%, and splitting tensile strength (MPa) is between 2.345 and 3.291 Mpa. Slake durability (Id1) ranges between 99.14 and 99.42, while slake durability (Id2) falls between (99.05 and 99.34).. The rest of the results were as follows: Voids (0.0112 to 0.029); porosity (1.11 to 2.82)%; water content% (0.16- 0.34)%; saturation % (28 to 55)%, while average dry specific gravity was 2.82. The results show that the basalt of the southern Jordan area (SJB) complies with the international standards, and the standards used for classifying the decorative and building stones. Therefore, this study recommends the use of SJB as a promising raw material to produce building aggregates. © 2020 Jordan Journal of Earth and Environmental Sciences. All rights reserved * Corresponding author e-mail: reyadn@hotmail.com Received 30 July 2019; Accepted 26 May 2020 JJEES (2020) 11 (4): 253-259 ISSN 1995-6681