Extrudability of cement-based composites reinforced with curauá (Ananas erectifolius) or polypropylene fibers

The aim of this research was to evaluate the influence of the curauá or polypropylene fibers on rheological properties of fresh cementitious paste. The variables were the percentage of fiber content 1 wt% or 2 wt% and the length of the curauá or polypropylene fibers: 6 or 10 mm, but it was also prepared paste without fibers as reference. Squeeze flow and ram extrusion tests were carried out to analyze the flow of the pastes. The hardened paste was evaluated by X-ray microtomography to observe the orientation of the fibers inside the paste. Curauá fiber led to higher force of extrusion and lower displacement of the fresh cement paste at the squeeze flow test and increased the pressure at the ram extrusion test in relation to polypropylene fibers, independently of the content and length. However, length of the same fiber presented higher influence on mixture flow than fiber content.