NONCONVENTIONAL ECOLOGICAL AND LOW-ENERGY CONSUMPTION TECHNIQUE TO PRODUCE HIGH-STRENGTH GEOPOLYMER COMPOSITE BASED ON RESIDUAL MATERIALS AS A NEW TYPE OF CONSTRUCTION MATERIAL

Abstract

High-strength geopolymer composite, a new type of construction material, based on granulated blast furnace slag and coal fly ash reinforced with PET fibres obtained by recycling and processing PET bottles was experimentally made. According to Davidovits' invention, an aqueous solution of sodium hydroxide and sodium silicate representing the alkaline activator was the basic element of the process favouring the development of the geopolymerization reaction, which involves the residual alumino-silicate materials (blast furnace slag and fly ash). The final curing process of the composite in the state of slurry poured into molds constituted the originality of the work by alternating the curing at room temperature for 20 hours with curing by maintaining the material at 75 ºC for 10 hours and then continuing the curing process at room temperature for 7 and 28 days respectively. The composite geopolymer had remarkable mechanical properties (compression strength of 60.1 MPa and flexural strength of 11.5 MPa) corresponding to the maximum proportion of PET fibres of 2.3 wt. % and final curing process time of 28 days. The composite made from residual materials is suitable for its use in ecological production conditions and with extremely low energy consumption.