Investigation of the properties of concretes produced wi̇th recycled asphalt aggregate

Concrete is the most preferred and widely consumed building material in the world. Aggregates constitute approximately 65-70% of the concrete volume, which consists of water, cement, aggregate and additives. A high amount of aggregate is needed in direct proportion to the preference of concrete so much. The use of aggregates at a high rate causes the depletion of natural resources and accordingly, great harm can be given to nature. In this thesis, it is aimed to investigate the usability of bituminous asphalt, which is the result of removing asphalt pavements that have completed their service life, as concrete aggregate. Thus, by recycling the idle bituminous asphalt, it will contribute to both concrete economy and environmental protection. Within the scope of the study, 3 different sets of concrete samples were prepared with a water/cement ratio of 0.4 and a cement dosage of 400 kg/m3. In the first set, recycled bituminous asphalt aggregate was replaced with natural crushed stone aggregate at the rates of 0%, 20%, 40%, 60%, 80% and 100%. In the 2nd set, recycled bituminous asphalt aggregate and basalt aggregate were replaced with natural crushed stone aggregate at the rates of 0%, 10%, 20%, 30%, 40% and 50% each. In the 3rd set, basalt aggregate was replaced by natural crushed stone aggregate at 0%, 20%, 40%, 60%, 80% and 100% by volume. Basalt aggregate was included in the study in order to compensate for the possible strength losses that may occur with the use of bituminous asphalt aggregate. After the 28-day curing period, the produced concrete samples were subjected to compressive strength, bending strength, test hammer, ultrasonic sound velocity, pull out, water absorption, capillarity, abrasion, rapid chlorine permeability and acid resistance tests at room temperature. In addition, in order to see the behavior of bituminous asphalt aggregate and basalt aggregate under high temperature, the samples were exposed separately to 200 oC and 400 oC temperatures for 2 hours, and pressure strength, ultrasonic sound velocity, pull out, water absorption and capillarity measurements were made. Experiment results showed that bituminous asphalt aggregate can be used as concrete aggregate with the displacement of natural crushed stone aggregate up to 40% by volume.