This study aims to examine the potential use of a geopolymeric matrix as a sustainable alternative to commercial mortars in carbon fabric-reinforced matrix composites. Single-lap shear tests were conducted to examine the bond behavior at the fabric-matrix interface. Test parameters included the type of matrix (geopolymeric and cementitious matrices) and the bonded length (50 to 300 mm). The geopolymeric matrix was a blend of fly ash/ground granulated blast furnace slag activated by an alkaline solution of sodium silicate and sodium hydroxide. The bond behavior of the geopolymeric-matrix specimens was characterized and compared to that of similar specimens with a cementitious matrix. The specimens failed due to fabric slippage/debonding at the fabric-matrix interface or fabric rupture. The effective bond lengths of the geopolymeric- and cementitious-matrix specimens were 150 and 170 mm, respectively. The geopolymeric-matrix specimens exhibited higher fabric strains, higher ultimate loads, and a steeper strain profile along the bonded length than those of their cementitious-matrix counterparts. New bond-slip models that characterize the bond behavior at the fabric-matrix interface for geopolymeric- and cementitious-matrix specimens were developed. Both models exhibited equal maximum shear stress of 1.2 MPa. The geopolymeric-matrix model had, however, higher fracture energy and higher slip at maximum shear stress than those of the cementitious matrix model.

This study conducts a scientometric review on the use of geopolymer mortar and composites in different construction applications. It aims to analyze the findings of past research and reveal the research constituents, development trends, and knowledge gaps. The Scopus database was employed to retrieve the relevant publications, while Bibliometrix was used to conduct the statistical analyses. Results revealed a steady and gradual increase in the number of publications after 2013, as the annual growth rate increased from 23.9% to 45.2% between the timeframes 2003–2013 and 2014–2022, respectively. The analysis highlighted that many authors collaborated on different construction applications of geopolymers regardless of geographic location. Meanwhile, Construction and Building Materials, China, and Universiti Malaysia Perlis were found to be the predominant journal, country, and institution, respectively. The scientometric analysis showed that the most frequently investigated applications for geopolymer mortars and composites were fire resistance, corrosion protection, and repair. Research gaps highlighted that other applications are not as well investigated despite the promising performance of the geopolymer composites, including 3D printing, heavy metals absorption, environmental protection, and underwater applications. Future research is required to assess the use of other alumina and silica-rich binders in geopolymers while also exploring their lifecycle assessment and economic impact.

This paper presents results of a pilot study carried out to investigate the feasibility and viability of producing a sustainable and eco-friendly structural strengthening solution involving the use of cement-free alkali-activated geopolymeric matrix and carbon fabric textiles. The study focused on examining the bond behavior at the fabric-geopolymeric matrix interface through single-lap shear tests. The geopolymeric matrix was a blend of fly ash/ground granulated blast furnace slag (GGBS) activated by an alkaline solution of sodium silicate and sodium hydroxide. Test parameters included the bonded length, configuration of the textile fabrics, and composition of the matrix. The bond behavior of the specimens with a geopolymeric matrix was characterized and compared to that of similar specimens with a cementitious matrix. All specimen exhibited a debonding mode of failure at the fabric-matrix interface. The bond strength of a specimen with a bi-directional fabric was higher than that of a similar specimen with a unidirectional fabric. The bond strength of the specimens with the geopolymeric matrix was even higher than that of similar specimens with the cementitious matrix. Increasing the fly ash-to-GGBS ratio in the geopolymeric matrix slightly decreased the bond strength but improved the post-peak behavior of the tested specimens.