Investigation of High Performance Fiber Reinforced Concrete Properties: High Early Strength, Toughness, Permeability and Fiber Distribution

Concrete cracking, high permeability and leaking joints allow for intrusion of harmful solutions, resulting in concrete deterioration and corrosion of reinforcement. The development of durable high performance concretes with limited cracking is a potential solution for extending the service life of the structures. Furthermore, the use of high early strength durable materials will facilitate rapid and effective repairs, reducing traffic interruptions and decreasing long-term maintenance costs.

The objective of this research was to develop low permeability durable materials that can achieve high early strengths within 24 and 10 hours. Within the scope of this work, various proportions of steel and synthetic fibers were used to evaluate crack control and post-cracking performance. In addition to high early strength and crack response other characteristics, including toughness, residual strengths, permeability of cracked concrete and fiber distribution were examined. Results from the investigation provide critical evidence that the implementation of high performance high early strength fiber reinforced concrete materials will significantly improve the condition of existing and new structures, and facilitate rapid effective repairs and construction.

The study has revealed that high early strength durable concretes can be achieved with proper attention to mixture components and properties, especially the amount of portland cement, accelerating admixtures and concrete temperature. Fiber reinforced concretes with steel fibers exhibited significantly higher toughness and residual strength values compare to those with polypropylene fibers. Permeability work showed that minor increase in crack width significantly increases infiltration of solutions. Fibers can facilitate crack width control. Fiber distribution analysis showed preferential alignment of steel fibers along the length of the beam. Proper mixing methods are essential for uniform random fiber distribution.