Key Engineering Materials Vol. 994

Abstract: The joining of metallic materials by using the friction stir welding process is carried out with rotating welding tools having different geometries. The paper presents aspects that show the influence of the conical profile of the welding tool pin on the dimensions of friction stir welded joints FSW in air and SFSW in liquid environment for EN AW 1200 aluminum alloy. The tools analyzed in the experimental research have had smooth conical pin and conical pin with four flat chamfers respectively, macrostructural investigations being carried out to a comparatively analyze of the welded joint dimensions. The results are useful for experimental research on FSP processing in air and SFSP in liquid environment of aluminum alloys that will be carried out within the Nucleu PN 23 37 01 02 project underway at ISIM Timisoara.

Abstract: This research aims to identify chemical composition and it’s leaching from concrete mixed with sugarcane bagasse ash. By manipulating percent of slump flow at 110±5%, sugarcane bagasse ash was employed as a pozzolanic material to partially replace cement at 0, 10, 20, 30, 40, and 50 percent by weight of binder in concrete. Cube specimens were cast and cured in water for 3, 7, 14 and, 28 days, respectively. The patterns of sugarcane bagasse ash morphology were performed by using Scanning Electron Microscope (SEM) to analyze physicochemical characteristics. Results of tests on the X-ray fluorescence (XRF) analysis from the ash and curing water at various times revealed that SiO₂ made up half of the components in sugarcane bagasse ash. Al₂O₃, CaO, Fe₂O₃, K₂O, P₂O₅, and MgO were the minor components. The calcium content from the 14-day period at 50% by weight of the sugarcane bagasse ash binder was higher than that of the other elements, according to the results of curing water. According to the results of 28-day water curing, potassium outnumbered all other elements in the replacement of sugarcane bagasse ash in every ratio.

Abstract: Due to emerging global environmental awareness, the increasing demand on synthesizing green materials for structural purposes became prevalent. This study utilized agricultural, aquacultural, and industrial waste as partial replacement for fine aggregates in concrete. One standard and six concrete samples with various proportions (20% and 40%) of rice husk ash (RHA), oyster shell powder (OSP), and ferrous powder (FeP) were constructed and tested for their mechanical properties (i.e., compressive and split tensile strength). The samples containing 20% and 40% FeP attained the highest compressive (22.71 MPa) and split tensile strength (1.379 MPa), respectively, which are closest to the control, M25 grade concrete (C-M25), (23.87 MPa), and (1.44 MPa), respectively. Concrete fracture analysis indicated that the cylinders were well constructed as implied by the fracture types. The C-FeP is the best concrete mixture attaining superior compressive and split tensile strength values.