Experimental Study on the Fracture Parameters of Concrete

Abstract

This study aimed to determine the influence of the volume fraction of steel fibers on the fracture parameters of concrete. Fifty notched steel-fiber-reinforced concrete (SFRC) beams and ordinary concrete beams with 100 mm × 100 mm × 515 mm were cast and tested via a three-point bending test. Among them, the type of steel fiber was the milling type (MF), and the volume fraction of steel fiber added was 0%, 0.5%, 1%, 1.5% and 2%, respectively. The effects of the steel fiber volume fraction (VF) on the critical stress intensity factor (KIC), fracture energy (GF), the deflection at failure(δ0), the critical crack mouth opening displacement (CMODC) and the critical crack tip opening displacement (CTODC) were studied. Through the analysis of test phenomena and test data such as the load-deflection (P-δ) curve, load-crack mouth opening displacement (P-CMOD) curve and load-crack tip opening displacement (P-CTOD) curve, the following conclusions are drawn: with the increase of the steel fiber volume fraction, some fracture parameters increase gradually and maintain a certain linear growth. The gain ratio of the fracture parameters increases significantly, and the gain effect is obvious. Through this law of growth, the experimental statistical formulas of fracture energy and the critical stress intensity factor are summarized.

Investigation on Fracture Behavior of Cementitious Composites Reinforced with Aligned Hooked-End Steel Fibers

“…When the CMOD of specimens exceeded about 0.2 mm, the load of the ASFRC specimen was still growing while the load of the SFRC specimen began to fall after the initial crack of the matrix. Specifically, the CMOD corresponding to the ultimate load of SFRC was generally not above 0.2 mm, which was also reported by Wang et al [35]. However, although the pre-initial crack behavior of ASFRC was similar with SFRC, the ASFRC specimen could still bear higher load until the peak load.…”

Assessment of the Specimen Size Effect on the Fracture Energy of Macro-Synthetic-Fiber-Reinforced Concrete

“…Scanning electronic microscopy results indicate that polypropylene fibers restrict the propagation of cracks, which improves the strength and durability of concrete [ 6 ]. Wang et al reported that with the increase in the steel fiber volume fraction, some fracture parameters increase gradually and maintain a certain linear growth [ 7 ].…”

Pressureless Immersion of Epoxy Resin-Filled Cracks in Faulted Rock Materials

“…Experimental results revealed a compressive strength of 40.6 MPa and a tensile strength of 12.6 MPa for the thinned epoxy material post-solidification, and infrared spectra analysis indicated an enhancement in the toughness of the epoxy material due to the inclusion of the diluent. Zhang et al [20] examined four common grouting materials-ordinary silicate cement, epoxy resin, ultrafine cement, and polyurethane-and conducted comprehensive analyses, considering factors such as grouting pressure and concrete crack aperture. They investigated the anti-seepage performance of each material on concrete cracks.…”