Study of the mechanical behavior of fiber-reinforced concrete through non-destructive testing

Several non-destructive mechanical tests can be used to assess the strength of concrete or mortar without crushing the specimens. In this study, prismatic specimens of glass fiber-reinforced concrete (GFRC) with different percentages (0%, 1%, 3%, and 5%) of ARHP-type glass fibers (high-performance alkali-resistant fibers) were used. Additionally, these GFRC specimens were exposed to different environments. A control series was kept in potable water, while the other series were maintained in seawater or a sulfate-rich environment. These specimens underwent mechanical and chemical tests. The results showed that adding fibers in proportions ranging from 1% to 5% slightly improved the density and strength of the concrete. However, immersing the GFRC specimens in a humid environment negatively affected the mechanical strength of the concrete, compromising its durability. Furthermore, it was observed that the carbonation depth was zero for all control specimens and those stored in seawater. Finally, the addition of 3% silica fume to the GFRC led to a slight improvement in strength but did not provide sufficient protection against the chemical degradation of fibers caused by alkaline or humid environments.