Tensile behavior of hybrid fiber reinforced composites made of strain-hardening cement-based composites (SHCC) and carbon textile

The paper at hand presents an experimental investigation into the tensile behavior of high-strength, strain-hardening cement-based composites (SHCC) reinforced with continuous carbon textile. Two SHCC under investigation were made of the same cementitious matrix but differed in the type of short fiber reinforcement, i.e., ultra-high molecular weight polyethylene (UHMWPE) fibers vs. as-spun poly( p-phenylene-2,6-benzobisoxazole) (PBO-AS) fibers. Two carbon textile variants used in the study consisted of the identical carbon fiber mesh and fiber content but had different impregnations: styrene-butadiene and polyacrylate polymers. Uniaxial tension tests were performed on all four combinations of SHCC and textiles as well as on the bare textiles, textiles embedded in plain cement-based matrix (without short fiber) as well as on SHCC without textile reinforcement. The hybrid reinforcement improved the tensile behavior of the composites considerably in comparison to that of materials containing only short fiber or textile reinforcement. Markedly higher first-crack stress and tensile strength were recorded, and at given strains considerably finer and more uniform crack patterns were observed. The combinations of PBO fiber and textile performed best in this respect. The composites containing carbon textile impregnated with polyacrylate exhibited considerably higher tensile strength and strain capacity than composites with styrene-butadiene-impregnated textile. The extensive parameter variation and material combinations, as well as the comprehensive mechanical investigations facilitated conclusions with respect to purposeful material design of cement-based composites with hybrid reinforcement. (C) 2020 Elsevier Ltd. All rights reserved.