Development of solution proposals to the abrasion problems of spillway with experimental methods: The porsuk Dam example

Spillways are the most important structures that maintain the static safety of dam structures. The safety of these structures makes the dam minimal impact against to hazards such as floods. Therefore, the durability of the spillway structures to the physical effects is very important. In the thesis primarily, the flood discharges which coming to pre-installed Porsuk Dam in the Porsuk basin is examined with Geographical Information Systems (GIS) to improve the abrasion problems of the spillway for the dam. Initially, the meteorological and hydrological data of the basin are investigated. Then the flood flow that comes from the basin is calculated for the Porsuk dam reservoir. By using the flood discharge, hydraulic loads and velocities that occur on the spillway were found. With reference to the concrete quality that used in the spillway of the dam, in order to prevent abrasion problems that may occur in these concretes, a long-lasting, abrasion-resistant spillway concrete type has been developed. In this study, fly ash (FA) and ground granulated blast furnace slag (GBFS) were replaced against by weight of cement with replacement ratios of 10 %, 20 % and 30 % in order to design the concrete mixtures. The abrasion behaviors of these concretes were determined by Böhme, sand water jet and underwater abrasion tests. As a result of the abrasion tests, it was determined that the best material performance was obtained from the GBFS 10 mixture. In the FA additive series, the FA 10 mixture showed similar abrasion loss with the reference concrete. As a result, it was determined that utilization of GBFS additive in water structures provides significant benefits against abrasion problems. It should also be noted that the usage of FA and GBFS in the dam concrete will provide positive gains in terms of both concrete cost and other durability problems.