The Effect of Hybrid Fibers Reinforcement on the Mechanical and Physical Properties of Concrete

Hybrid fiber reinforced concrete is the use of two or more than two fiber textures in a single concrete matrix to improve the overall properties of concrete.

In this study, the ductility of medium strength concrete was observed to improve by incorporating steel and polypropylene in a ratio of 50:50 as a hybrid fiber. Four proportions of Volume fractions (V_f) were used (0.25, 0.5, 0.75, 1%). The changes in the mechanical properties and density occurred due to the addition of these hybrid fibers.

The features examined include bulk density, compressive strength, and flexural strength by using thirteen concrete mixtures with various volume fractions of steel and polypropylene fibers.

The results showed a significant increase in compressive and flexural strength due to the addition of steel fibers. On the other hand, polypropylene fibers exhibited minor changes in the mechanical properties of hardened concrete exclusively in the mixtures made with both steel and polypropylene fibers in which the strength increased in comparison to plain concrete by 4.4% and to steel fiber group having the optimal strength and other properties.

These remarks provide a clear view of the importance of using different fiber reinforcing systems to improve the mechanical performance of concrete, which is considered quasi-brittle.