Development of gypsum‐based composites with tensile strain‐hardening characteristics

Abstract

Brittle nature of gypsum restrains its wide application in construction industry. For improvement, a novel type of composite material, gypsum-based engineered cementitious composites (GS-ECC), was developed using specially chosen polyethylene (PE) fibers. This study investigated the rheological and mechanical properties of GS-ECC, that is, workability, uniaxial tensile and compressive behavior, flexural strength, etc The investigation showed that GS-ECC possessed excellent tensile strain-hardening behavior and saturated cracking characteristics with the average tensile strain capacity more than 5%. To explore the underlying mechanism, the microstructure of interface transition zone (ITZ) between gypsum crystals and PE fibers were investigated through the use of SEM. Single fiber pull-out test, bending-fracture test, and single crack tension test were conducted to investigate the mesoscopic properties from fiber/matrix interface to matrix toughness and fiber bridging capacity. This study demonstrates the feasibility of achieving strain-hardening gypsum-based composites by adding the PE fibers. K E Y W O R D S fiber-matrix interface, gypsum, polyethylene fiber, strain hardening gypsum composite, ultra-high ductility How to cite this article: Wang Y, Jian X, Yu J, Ye J, Dong F. Development of gypsum-based composites with tensile strain-hardening characteristics.

Performance Test and Microstructure of Modified PVC Aggregate-Hybrid Fiber Reinforced Engineering Cementitious Composite (ECC)

“…Water and water reducing agent were added for wet mixing for 5 min. When the slurry flowed uniformly, fibers were slowly added and stirred for about 10 min until uniform a dispersion was achieved [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. The mixture was poured into a mold, vibrated, and cured at room temperature for 36 h. Finally, the mixture was cured in standard curing room for 28 days.…”

“…Second, the cost of cementitious materials in ECC decreases by reducing the amount of cement and using some environmentally friendly cementitious materials, such as fly ash. This method has been widely used [ 11 , 15 , 16 , 17 ]. Wang et al [ 11 ] improved the strength of cementitious material by adding calcium sulfate, and the content of fly ash accounted for 60% of the cementitious material.…”

Surface-Functionalized Nanocelluloses as Viscosity-Modifying Agents in Engineered Cementitious Composites

“…Viscosity-modifying agent (VMA) based on cellulose ethers, such as hydroxyethylmethyl cellulose (HEC) or hydroxypropylmethyl cellulose (HPMC), is commonly used to improve the workability and stability of the fresh concrete mixture. In terms of ECC, VMA as an admixture was added to adjust the rheological properties of the fresh matrices for achieving a uniform dispersion of fibers in previous studies (Wang et al, 2020a;Wang et al, 2020b) considering that CNF also can impact the rheological performance of the fresh paste, and it is reported that CNF results in the enhancement of the microstructure and mechanical properties of cement-based materials (Ghahari et al, 2020;Hisseine et al, 2020). In this study, CNF, regarded as an alternative to common VMA, was used to develop and reinforce ECC.…”