Journal of Civil Engineering Beyond Limits (CEBEL)

Saad Issa Sarsam

Permanent deformation is considered as one of the major distress type of asphalt concrete pavement in the hot climate region. It can be controlled by the use of additives either for asphalt binder or for the asphalt concrete mixture. In the present assessment, the impact of micro and Nano size additives (fly ash and silica fumes) on the deformation behaviour of asphalt concrete mixtures was assessed. Such additives were implemented as partial substitute of mineral filler. Asphalt concrete slab samples were prepared in the laboratory with the aid of roller compaction. The optimum percentages of the additives are (2 and 4) % of silica fumes and coal fly ash respectively by the weight of the binder. Beam specimens were obtained from the slab samples and tested for fatigue life under three constant strain levels using four point bending beam technique. It was observed that for mixture treated with Nano additive (silica fumes), the reduction in the permanent deformation starts at 0.0001 MJ/m3 loss in energy for 750 microstrain level. However, for mixture treated with Micro size additive (fly ash), as the dissipated energy vanishes, the permanent deformation was in the range of (3 - 4.5) microstrain. It was concluded that as the dissipated energy vanishes, the permanent deformation was lower by (29.4 and 11.7) % for mixtures treated with silica fumes and fly ash additives respectively as compared with the control mixture.

https://doi.org/10.36937/cebel.2023.1769

Ahmad Jamshid Sadid Abdulkadir Cüneyt Aydın

The usage of cold-formed steel (CFS) is gaining popularity all around the world these days. Buildings made of such elements as an independent structural system are applied in the construction of small commercial complexes, low-raised buildings, industrial units, and single-story sports halls. CFS shear walls sheathed with steel sheets are the most popular lateral-load resisting system in low to mid-raised structures. In this paper, a full-scale steel seated CFS shear wall has been simulated by a non-linear finite element method. Furthermore, parametric studies have been carried out to analyze the effects of the blocking members, fastener spacing at steel plate to boundary frame connections, and steel sheet thickness on the behavior of CFS shear wall sheathed with steel plate. It was concluded that the blocking members prevent the studs from twisting and decrease the local bucking of the studs. Meanwhile, the results indicate that the thickness of the steel plate affects the shear strength of the CFS shear wall system to an extent. Besides, increasing the spacing of the fasteners at the connection of the steel plate to the frame system affects the buckling mode of the steel plate, and by increasing the spacing of the fasteners from 100 mm to 150 mm and 200 mm the nominal shear strength of the wall system decreased by 6.5% and 14.1% respectively, while decreasing the fastener spacing causes web distortion of the boundary column elements.

https://doi.org/10.36937/cebel.2023.1772

Esra Mete Güneyisi Tayfun Çınar

In this study, the nonlinear analysis and seismic appraisal of composite frames having concrete filled steel tube columns (CFSTs) were investigated. The case study composite frames were made of the square columns surrounded by steel tube outside and infilled with concrete, and also steel I beams. These frames were taken as 4, 6 and 8 stories with three equal bays. Then, the nonlinear pushover analysis was applied to examine the influence of variation in the width-thickness ratio, slenderness ratio, yield strength of the steel tube and compressive strength of the concrete within the columns of each frame. Thus, a total of seventy-two different composite frame models with CFST columns and steel beams were examined in accordance with the response parameter of the base shear-top displacement. The obtained results were discussed comparatively as per the lateral capacity and initial stiffness. It was observed that the material and dimensional properties of the CFST columns influenced significantly the seismic behavior of the composite frames.

https://doi.org/10.36937/cebel.2023.1787

Ivan Musiiaka Oleksandr Molodid Ivan Reznichenko Ruslana Plokhuta

During reconstruction the sewerage collector found an intense water leak inward construction at a junction of fiberglass pipes (mounted at the last reconstruction) to an outer reinforced concrete structures of the chambers. It’s known that similar defects eliminate using of cementation, clay, silicate or other methods such as injections of special repair mortars for an outer jacket. The authors of a current article carried out experimental research on pressurizing cavities by polyurethane material SPT® Resins. According to a plan of a research study of the efficient and feasibility of four technological solutions of junction pressurizing between segments of concrete pipe and polyurethane material SPT® in conditions close to real ware stipulated. The technological solutions consist in installing a spreading rim on a gap and filling the gap between rim and pipe segment on both sides with: polyurethane foam; rubber hollow sealant; polyurethane sealant. The fourth technological solution stipulated filling the joint between concrete segments of pipe by splattering polyurethane material SPT® Resins on the surface of the conjunction with the applicator. The results of experimental studies have shown that using first three technological solutions allow filling the junction cavities with repair material for 96-99% of the total volume of the cavities. In this case, water leakage inward construction through junction is eliminated. To validate experimental research was performed by pressurizing one of the junctions in chamber KK-8 with polyurethane material SPT® Resins by injection method. Further monitoring of repaired area made it possible to recommend a developed design and technological solution for pressurizing remaining joints.

https://doi.org/10.36937/cebel.2023.1775