Dimensional stability of deflection‐hardening hybrid fiber reinforced concretes with coarse aggregate: Suppressing restrained shrinkage cracking

Abstract

High Performance Fiber Reinforced Concretes (HPFRCs) with deflection‐hardening capability are relatively novel materials with high damage tolerance. However, mixture proportions of such materials are mostly designed with fine aggregates for easier/homogenous fiber distribution and low matrix fracture toughness which increases the amount of cementitious materials as the main binder and related risk for dimensional instability, high cost, and environmental unfriendliness. Here, with the idea of developing concrete that is free of shrinkage‐related cracking at a more reasonable price, deflection‐hardening HPFRC mixtures incorporating different amounts of coarse aggregates (with maximum size of 12 mm) were developed with different mixture parameters (fiber types/dosages and fly ash contents) and tested for their dimensional stability by focusing mainly on the drying and restrained shrinkage measurements. Experimental results reveal that the combined effectiveness of utilizing hybrid fiber reinforcement and high amounts of coarse aggregates by properly adjusting the matrix properties without compromising high ductility (deflection‐hardening behavior) can help the realization of possible producibility of HPFRC mixtures that are completely free of restrained shrinkage‐related cracking. The findings of this study are believed to make a significant impact on the wide‐spread usage of deflection‐hardening HPFRC mixtures with similar ingredients to that of conventional concrete in actual field conditions.

Effect Polypropylene of Fiber on Drying Shrinkage Cracking of Concrete Pavement Using Response Surface Methodology

“…Forms of weight loss have proven this. Before 14 days of age, the weights of specimens declined sharply level-off after 28 days [14].…”

On enhancing the mechanical behavior of ultra-high performance concrete through multi-scale fiber reinforcement

“…There have been very few studies on the use of multi-scale fiber reinforcement in UHPC, but a similar approach has been implemented in other cementitious composites. For instance, hybrid fiber-reinforced, normal strength concrete containing both small (micro) and large (macro) steel fibers has been observed to exhibit greater fracture toughness and flexural/tensile strength than mono fiber-reinforced concrete [29][30][31][32][33][34][35]. Similarly, the addition of carbon nanofibers at 0.3% volume fraction has been observed to enhance the steel fiber-matrix bond, which results in significant increases in the tensile and flexural strengths of a UHPC [36].…”

Mechanical Properties of Polypropylene-Fiber-Reinforced High-Performance Concrete Based on the Response Surface Method

“…In recent years, the application of synthetic organic fibers represented by polyethylene fiber [3], polyvinyl alcohol fiber [4], and polypropylene fiber (PPF) [5,6] in HPC has made great progress. Considering that synthetic organic fibers can significantly improve structure's crack resistance, reduce the shrinkage crack [7], enhance the ductility [8], and affect the resistance of concrete [9], such fibers can effectively improve the wear resistance, impermeability, and tensile strength of FRHPC [10]. ey can also improve the working performance of concrete and reduce the brittleness of concrete [11,12]; thus, they are applied in bridge and pavement engineering [13].…”