Mechanical Properties of Silica-Based Geopolymer Composites Cured at Ambient Conditions in Accordance with Size-Independent Method

Abstract

In this paper, silica-based geopolymer matrix reinforced composites containing approximately 35, 50 or 55 wt.% of carbon (HTS 5631 1600tex 24K, TohoTenax), advanced basalt (BCF13-2520tex KV12 Int, Basaltex) or electrical grade glass (E-glass: E2400P192, Saint-Gobain, Vetrotex) roving fibers respectively were synthesized and fabricated at ambient conditions. The flexural properties of the resulting composites which are high toughness: the shear stress plays here a greater role in compared with other ceramic matrix composites were determined on a universal testing machine under three-point bending mode in accordance with novel size-independent method which based on testing specimens at different scale of sample height (H) to span length (L) ratios; The basic principles of the new size-independent approach are presented as well. Microstructures of composites were analyzed by means of scanning electron microscope (SEM) on perpendicular sections, the images show the adhesion between the fibers and geopolymer matrix are very good, and micro-cracks on both cross-sections and surfaces of geocomposites are determined as inborn defects of inorganic matrix composites.