Compression behavior of 1D and 2D aligned steel fiber reinforced cement-based composites

The compressive performance of steel fiber reinforced cement-based composites is highly affected by fiber orientation. In this study, specimens of cement-based composites with unidirectionally and two-dimensionally aligned steel fibers (1D-ASFRC and 2D-ASFRC) were manufactured based on electromagnetic field treatment, and the cubic compressive and prism uniaxial compressive test were conducted. The results showed that compared with randomly distributed steel fiber reinforced cement-based composites (SFRC), the cubic compressive strength of 1D-ASFRC and 2D-ASFRC was increased up to 9.4 % and 15.7 %, respectively. The uniaxial compressive strength of 2D-ASFRC and 1D-ASFRC rose by over 4 % and 8.9 %. Additionally, compression absorbed energy and compression toughness ratio were also observed an increasing trend for 1D-ASFRC and 2D-ASFRC. The fiber orientation influence coefficient was proposed to characterize the contribution of fiber orientation on the uniaxial compressive behavior, and the stress–strain constitutive models of SFRC, 1D-ASFRC and 2D-ASFRC were established. The failure patterns of 2D-ASFRC were found to be different from that of SFRC. A typical oblique shear failure mode can be observed in SFRC and 1D-ASFRC specimens, while 2D-ASFRC demonstrated the improved compression toughness with multiple discontinuous narrow cracks and without penetrating cracks. The reinforcement mechanism of 1D- and 2D- aligned steel fibers was revealed from fiber distribution.