Mechanical and physical properties of artificial lightweight aggregate used in geopolymer concrete

Scholars all over the world are becoming increasingly interested in the production of lightweight building materials through the utilization of wastes and by-products. In the current study, the focus is on the production of lightweight artificial aggregates and some of their mechanical and physical properties. Besides it presents the result of utilizing artificial aggregate on the characteristics of concrete with slag and fly ash activated by alkali and cured at room temperature. In addition, it has been checked against acid attacks to measure the durability of the concrete produced with the optimum artificial aggregate content. The production of artificial aggregate was accomplished by the cold-bonded method. Initially, the production of four types of aggregate were pelletizing in a powder form asType1 (40% Fly ash, 40% Slag, 20% cement), Type 2 (90% Slag and 10% Portland cement), Type 3 (50% Fly ash and 50% cement) and Type 4 (30% Fly ash ,70% Cement). Thereafter, the all-natural coarse aggregate, replaced by the artificial light aggregate, was used in 3 different geopolymer concrete compositions with a sodium hydroxide content of 12 M. The main objectives of this study are to investigate the strength properties, density, water absorption, microstructure of the artificial aggregate and to find the compressive strength. Moreover, the strength properties through compressive strength and splitting tensile strength of the Geopolymer concrete have been conducted. According to the test results, 80% of type 1 and 20% of type 2 artificial aggregate ratio have been determined as the optimum ratios. It has been founded that compressive strength and splitting tensile strength values as 47.60 MPa and 2.85 MPa respectively, with this optimum ratio. Key Words: Artificial Lightweight Aggregate, Geopolymer Concrete, Ground Granulated Blast Furnace Slag, Ordinary Portland Cement, Fly Ash