Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2021Experimental Investigation of Usability of Construction Waste as Aggregate
Kulekci, Gokhan; Yilmaz, Ali Osman; Cullu, Mustafa
The aim of this work is to obtain recycled aggregate (RA) from construction debris in order to reduce the rapid consumption of aggregate resources and the environmental impact of these resources. In order to fulfill this aim, the density, porosity, Schmidt hardness test, uniaxial compression resistance, carbonation depth, and ultrasonic p-wave velocity experiments were conducted on different construction debris transported by trucks from 9 different points in Turkey. In addition, the debris samples taken were broken down to the size of the aggregate and subjected to the tests of density, porosity, moisture content, freeze-thaw, and impact resistance. As a result of the conducted experiments, the lowest mass loss as a result of freezing-thawing was in GRA with 9.36%, the highest mass loss was in ORA with 22.58%, the highest ORA average aggregate impact strength index was 21.27%, and the lowest TRA aggregate impact strength index was found to be 18.26%. İt was determined that most of the physical properties of RA obtained from the construction wreckage was within the limit values specified in the literature and that the recycled aggregates could be used instead of natural aggregate. With this work and these results, RA obtained could be used in many areas such as concrete aggregate in the construction sector, underground filling in mining, filling material in gunned concrete, and filling materials on highways.
- MakaleYalnız künye2019Stability evaluation of the Gümüşhane-Akçakale cave by numerical analysis method
Alemdag, Selcuk; Zeybek, Halil Ibrahim; Kulekci, Gokhan
The Akçakale Cave is located in the vicinity of the Arsa neighborhood within the boundaries of the Akçakale village, Gümüşhane, Turkey. The cave is rich in cave formations (stalactite, stalagmite, cave pearl, cave flower, wall travertines). Thus, the appropriateness of opening the cave to visitors to boost tourism is of importance for the local and national economy. This study analyzes the stability of the Akçakale Cave using a numerical analysis method. According to the results of the total displacement analysis, there are displacements in the entrance, ceiling, and sidewalls of the cave ranging from 1 mm to 48 mm. It seems that the entrance, ceiling, and sidewalls of the cave face a high risk of local or sudden collapse. According to the deformation analysis of the length section of the cave examined, local collapses may occur especially in the first 75 m from the entrance of the cave. We believe that this situation would not carry a risk for the Arsa neighborhood for now. In conclusion, the results of the stability analysis and in-situ observations showed clear evidence of former and ongoing cave-ins (collapses) and the Akçakale Cave faces a high risk of local or sudden collapse. Thus, although the Akçakale Cave is one of the most prominent karst caves in Turkey, it seems to be not appropriate to open the cave to tourist visits.