Actual achievements and future challenges of HPFRC for structural rehabilitation of bridges

Abstract

The state of road infrastructures in many advanced countries is rapidly changing under the impulse of massive funding from governments, eager to have more efficient and safer transportation systems. The use of well-known materials such as fibre-reinforced concrete (FRC) is finding a growing space for structural rehabilitation of bridges; the adopted material is often defined as High performance fibre reinforced concrete (HPFRC) due to its enhanced performance. The paper presents the principal findings of an EU-funded project that involved the repair of two road bridges in Italy using HPFRC. The project has successfully carried out the jacketing of bridge piers and cap-beams, heavily damaged by corrosion, with a new HPFRC layer of reduced thickness (40-60 mm) and limited use of steel reinforcements. Experimental tests carried out in the laboratory of the University of Brescia on 1:2 scaled specimens have shown the possibility to increase the load bearing capacity of the cap beams (with respect to vertical loading) up to 73%, with moderate effects on the change in stiffness and ductility of the existing structure. Based on field and laboratory experience, the article eventually presents some new challenges for the use of HPFRC in the reduction of environmental impact of construction industry.

Concrete Strength Enhancement due to High‐Performance Fibre‐Reinforced Concrete Jacketing Solution

“…When loading exceeds 70% of concrete strength capacity, the concrete behaves differently due to reaching non-elastic stage [3]. In the non-elastic stage, the concrete exhibits internal damage and will be permanently deformed, which indicates the end of service life.…”

“…In addition, they are much cheaper than steel plates and fibre-reinforced polymer (FRP) jacketing solutions. Studies have shown that HPFRC jackets improve the load-bearing capacity, ductility, energy dissipation, and durability of concrete structures [2,3]. Nevertheless, the strength enhancement due to HPFRC jacketing and the relationship between the normal strength concrete (NSC) substrate and HPFRC jacket are unclear.…”