SEM and 3D microtomography application to investigate the distribution of fibers in advanced cementitious composites

Abstract

The incorporation of fibers on cement composites reduces its fragility, turning it a ductile material. The amount of fibers and its distribution presents a large influence on the composite performance, especially by the fact that it is self-consolidating, which facilitates the fiber distribution. 3D microtomography is an efficient tool for determining the fibers distribution, generating images and creating a representation in three dimensions of the sample. Moreover, the scanning electron microscopy (SEM) can be used to analyze the interaction of fibers with the cement composite. The purpose of this paper is to investigate the application of these techniques to visualize the distribution and interaction of metallic and polypropylene fibers inserted into an advanced cementitious composite, at 3% in volume content. The results presented these techniques' efficiency in the verification of fibers distribution within the mixture and the absence of flaws in the composition.

Determination of volume and distribution of pores of concretes according to different exposure classes through 3D microtomography and mercury intrusion porosimetry

“…An evaluation of cement pastes at different ages combining the techniques of 3D microtomography and scanning electron microscopy pointed out the presence of voids and anhydrous cement . Such techniques were also used for assessing a matrix of advanced cementitious composites, whereas focusing on the interface between fibers and cement paste . The procedure turned out to be appropriate for analyzing the transitioning zone between paste and fiber, pointing towards an adequate adherence with no void agglomerations.…”

“…27 Such techniques were also used for assessing a matrix of advanced cementitious composites, whereas focusing on the interface between fibers and cement paste. 23 The procedure turned out to be appropriate for analyzing the transitioning zone between paste and fiber, pointing towards an adequate adherence with no void agglomerations. Finally, this procedure was put into use for measuring and analyzing the distribution of voids with respect to pore size of a fiber-reinforced concrete, resulting in a void diameter preponderantly between 0.39 and 0.77 mm.…”

Effects of fiber hybridization in advanced cementitious composites durability in humid and aggressive environments

“…Pacheco et al (2016) [25] verified, through SEM, the interface between fibers and the cementitious matrix is not characterized as a fragile zone or accumulation of voids, and no affects the compactness of the material. Stamatina et al (2017) [26] affirm that one of the reasons of hybridity is the improvement of the mechanical and early age properties.…”

Study on concrete through its hardened state properties

“…Concrete structures have been used worldwide for over 100 years due to their properties of resistance, versatility and load carrying capacity, in addition to mastery and vast knowledge of this technology [1][2][3][4] . Amid this period, professionals could learn the main characteristics of concrete and how these relate to durability and performance, and how to preserve the proper-ties.…”