چكيده به لاتين
Due to the annual production of large volumes of concrete around the world and the indiscriminate use of cement and the subsequent release of carbon dioxide into the atmosphere, we have witnessed a lot of environmental pollution from this widely used industry. There are different types of cement substitutes and pozzolans that are used and considered by concrete manufacturers according to the conditions of mines and factories in each country, cost, availability, desired properties and type of application. Geopolymer concrete, which has a new technology and has been extensively researched and developed in recent decades, is a suitable option as well as a suitable alternative to cement or pozzolans. Pozzolanic materials have been widely used in many applications in the manufacture of Portland cement due to their beneficial properties including new cement matrices which include cost reduction, reduction in hydration heating, lower permeability, denser microstructure, higher durability, better chemical resistance, etc.
Among the by-products of pozzolans, the focus of academic research in the field of geopolymeric materials has generally been on fly ash, and the use of copper slag is less common. Despite the fact that Iran annually produces three hundred and sixty thousand tons of copper slag, except in the case of sandblasting, this material has no significant use. Therefore, the application of this material in concrete can be one of the ways to reduce its accumulation in our environment. According to the above cases, the purpose of this study is to investigate the mechanical properties and durability of geopolymer mortars based on copper slag, smelting furnace slag and metakaolin.
Initially, the effect of sodium hydroxide solution concentration was tested by trial and error in 13 initial mixture designs. Then the concentration of 16 M was selected as the optimal concentration and 13 main mix designs according to the standard were examined with the increasing effect of copper slag. The properties of geopolymer mortar with the influence of these factors have been evaluated by experiments such as compressive strength, flexural strength, tensile strength, microstructural microscopic images (SEM), nitrogen porosity, volumetric water absorption, accelerated chloride ion migration (RCMT). XRF and XRD of all materials were also prepared.
The results of the present study showed that in order to maximize mechanical strength in metakaolin geopolymer samples, 10% replacement of copper slag is required. Also, in order to maximize the mechanical strength in geopolymer samples of smelting furnace slag, 20% replacement of copper slag is required. On the other hand, the results of ultrasonic waves indicate the optimal use of 30% replacement of copper slag in metakaolin and smelting furnace slag, which is inversely related to the compressive strength test. According to the water absorption test, the amount of water absorption of the cement sample is slightly lower than the geopolymer samples containing metakaolin and is almost equal to the water absorption results of the geopolymer samples containing the slag of the smelting furnace.
