Abstract
In this study, the combined effects of different amounts of graphite tailings (GT) as a substitute for sand and three cure methods on the early‐age mechanical and material performances of cement mortar have been investigated. The results can be concluded that graphite tailings and hot‐water cure method can effectively improve the early strength of cement‐based materials and facilitate the formation of high‐density calcium silicate hydrate (C‐S‐H), more Ca(OH)2 (CH), and other hydration products. Simultaneously, the pore structure distribution in the cement mortar is improved to be finer. Finally, this paper explains the mechanism of GT and hot‐water curing (HWC) method on early‐age performances of the cement mortar through the graphic model and provides the basis for selecting the GT and HWC method on improving early performance requirements for special engineering or rapid repair engineering through the proposed comprehensive quantitative calculation model.
Highlights
Cement-based materials are the most widely used building materials worldwide
(3) Early-strength cement-based materials are of great significance for the repair, reinforcement, and renewal of airport runways, expressways, ports, and terminals. (4) e study of the early strength property provides a basis and support for high-strength concrete, high-performance concrete, or ultrahigh-strength concrete. e work was driven by the military, important projects, mass production, and industrialization requirements for building materials to be ready rapidly and in an economical way. e performance of cement-based materials at an early time and their immediate use are the result of scientific research, engineering needs, and the industry developments [9,10,11,12]
Specimen Casting and Curing Conditions. e graphite tailing-cement mortar (GTCM) specimens had dimensions of 40 mm × 40 mm × 160 mm and were demolded after 24 h in accordance with the Chinese standard GB/T 17671-1999 [33]. e curing schemes are listed in Table 6. e standard curing method (SC method) is performed in a steam curing room with a temperature of 20 ± 2°C and a relative humidity of 95%, and the hot-water curing method (HWC method) is performed in a water bath apparatus (HH-F). e combination curing method (CC method) includes the aforementioned two methods as follows
Summary
Cement-based materials are the most widely used building materials worldwide. In recent decades, the composition and characteristics of cements, such as the hydration process, mechanical properties, durability, workability, material properties, pore structures, and C-S-H content, have been extensively studied from a physical and chemical perspective [1,2,3]. Some published studies on building materials containing GT have evaluated their suitability and mechanistic performance improvement or mesostructure changes, research on changing the properties of cement-based materials with GT is still in its infancy. There have been no studies conducted with a focus on the effects of incorporating GT in concrete or cement mortar for increased early strength and associated curing methods that would enable rapid construction and efficient structural use. E goal of this study is to fill these research gaps by investigating the early strength and material characteristics of cement mortar that incorporates GT as a replacement for sand as a fine aggregate and is subjected to different curing conditions.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
