This study looked at the state-of-the-art present knowledge base and trends in the area of using rejuvenators in reclaimed asphalt pavement (RAP) by systemic analysis and visualisation using VOSviewer and Scopus analyser; a total of 1872 studies were mined from the Scopus database for the purpose of this study. This quantitative approach to the review of literature removes author bias. The study was able to identify keywords and their cluster groups making up of core research domains ((1) asphalt binder composition and properties, (2) reclaimed asphalt mixtures (recycling), (3) reclaimed asphalt performance characteristics, (4) reclaimed asphalt sustainability, (5) rejuvenating agents and their performance, and (6) area of application). The study was able to identify the top authors; their document counts and citations; the most influential journals, institutions, and countries leading the way in the research domain; and the link between these authors and keywords within the existing body of literature in the research area. This study will help policymakers in identifying the main research themes and possible area of investments for further research in RAP. This study will also be a valuable compendium to researchers who intend to broaden the scope of the research area.
Every structure might be exposed to fire at some point in its lifecycle. The ability of geopolymer composites to withstand the effects of fire damage early before it is put out is of great importance. This study examined the effects of fire on geopolymer composite samples made with high-calcium fly ash and alkaline solution synthesised from waste banana peduncle and silica fume. A ratio of 0.30, 0.35, and 0.4 was used in the study for the alkaline solution to fly ash. Also used were ratios of 0.5, 0.75, and 1 for silica oxide (silica fume) to potassium hydroxide ratio. The strength loss, residual compressive strength, percentage strength loss, relative residual compressive strength, ultrasonic pulse velocity, and microstructural properties of the thirteen mortar mixes were measured after exposure to temperatures of 200, 400, 600, and 800 °C for 1 h, respectively. The results reveal that geopolymer samples exposed to elevated temperatures showed great dimensional stability with no visible surface cracks. There was a colour transition from dark grey to whitish brown for the green geopolymer mortar and brown to whitish brown for the control sample. As the temperature rose, weight loss became more pronounced, with 800 °C producing the most significant weight reduction. The optimum mixes had a residual compressive strength of 25.02 MPa after being exposed to 200 °C, 18.72 MPa after being exposed to 400 °C, 14.04 MPa after being exposed to 600 °C, and 7.41 MPa after being exposed to 800 °C. The control had a residual compressive strength of 8.45 MPa after being exposed to 200 °C, 6.67 MPa after being exposed to 400 °C, 3.16 MPa after being exposed to 600 °C, and 2.23 MPa after being exposed to 800 °C. The relative residual compressive strength decreases for green geopolymer mortar are most significant at 600 and 800 °C, with an average decrease of 0.47 and 0.30, respectively. The microstructure of the samples revealed various phase changes and new product formations as the temperature increased.