Investigation of the physical and mechanical properties of geopolymer mortars manufactured using methaolin and recycled concrete aggregate

The world population is increasing exponentially day by day and the demand for shelter, which is one of the most basic needs of people, is increasing rapidly. In order to meet this demand, the first building material used by mankind is concrete. While the production of cement, which is one of the basic raw materials used in concrete production, consumes a lot of energy, the most important damage is CO2 and other harmful gases released during its production, triggering global warming, causing irreversible damage to the earth. In addition, natural resources of aggregates, which are other raw materials, are depleted. As a result of the studies carried out so far, geopolymer concrete has been presented as an alternative to cementitious concrete. The logic of geopolymer concrete is the use of waste. The aim of this thesis is to produce a geopolymer mortar with carrier properties by using mostly waste materials. In the study, instead of cement, ground blast furnace slag and fly ash, which are industrial wastes, together with metakaolin were used. In order to move forward with the waste usage logic, recycled concrete pieces taken from the construction demolition wastes in the form of rubble were grinded and used as aggregate. NaOH and Na2SiO3 were used for alkali activation of mortars in which ground blast furnace slag, fly ash and metakaolin were substituted at different rates as binders. The samples were exposed to oven curing at 100oC for 72 hours. In order to examine the effect of binder type on the produced samples, experiments were carried out to determine the physical, mechanical and durability properties. Considering the test results, YM2 series with the highest compressive strength (90% ground blast furnace slag and 10% metakaolin) reached 30.50 MPa. Again, the bending strength of the same series is 9.35 MPa, which is the highest value among the series. The results are satisfactory when compared with cementitious mortars with bearing properties..