Investigation of behavior of reversed recurrent horizontal loads of columns produced by mineral admixture under corrosion effect

Corrosion threatens reinforced concrete buildings throughout their service life and it is considered as one of the main factors for buildings to lose their horizontal displacement capacities due to destruction caused on reinforcement by corrosion. Field research that are made after the devastating earthquakes indicates that corrosion of reinforcement elements and deteriorated adherence between concrete and reinforcement lead to destroyed or heavily damaged buildings. In addition, it is well-known that, columns are the most critical elements for structural safety during earthquakes. For this reason, it is of great importance for a country like Turkey located in an active earthquake zone to investigate the behaviors of corroded reinforced concrete columns particularly under lateral load and investigate measures to be accounted. In this thesis, the effect of using blast furnace slag (BFS) and fly ash (FA) replacing with CEM I 42.5R cement were experimentally investigated on the reinforcement corrosion in reinforced concrete column together with its positive / negative contribution to the behavior of columns under lateral load. For this purpose, three reinforced concrete column specimens incorporating cement by dosage of 280 kg / m3 that do not contain mineral admixtures were produced as CONTROL series. In the mineral incorporating series, 12 reinforced concrete column specimens were produced by using 20% and 40% BFS and 10% and 20% FA instead of cement with three of each series. Then, one of the three columns produced for each series was selected as a reference, the rest of two column specimens were subjected to corrosion under constant voltage until theoretically 10% and 30% weight losses were reached using the Faraday equation in the reinforcement. After accelerated corrosion tests, the specimens were tested under reversed-cyclic lateral load that simulates the earthquake effect. After the lateral loading test, the reinforcements were removed one by one from rust and concrete residues with special solutions (HCl acid solution). Thus, the weights of the rebars were weighed and compared with the initial weights and the actual corrosion levels in the specimens were determined and discussed. Experimental results show that the use of mineral admixtures in concrete production reduces the risk of corrosion of reinforced concrete elements and improves earthquake behavior.