High-strength Concrete with Natural Aggregates, Silica Fume, and Polypropylene Macrofibers

The use of concrete with polypropylene macrofibers can reduce the fragility and shrinkage of silica fume mixtures. Here, we investigated the effect silica fumes and aggregates have on enhancing high-performance concrete with polypropylene macrofibers. Three dosages of polypropylene macrofibers were evaluated (0.39, 0.63, and 0.79 % volume fraction), including silica fume (0.0 and 7.0 % water-cement), for two types of coarse aggregate (limestone and river gravel), with two maximum nominal sizes of coarse aggregate. In total, 96 concrete specimens were subjected to compression and bending tests to evaluate the effect of adding fiber, silica fume, and different aggregate types. The results showed a resistance to compression between 36 and 71 MPa, and that to flexural strengths of 3.6 to 5.8 MPa, which indicates high-performance concrete. The work shows that it is possible to achieve high-strength concrete with 55 mm polypropylene macrofibers combined with silica fumes and natural aggregates of both the limestone and calcareous types, which is beneficial for the local production of high-performance concrete.