Outer Reinforcement Research Articles

Effects of exposure to saline humidity on bond between GFRP and concrete

Abstract Based on extensive experimental program on effects of artificial environmental aging, its effects on strength and bond between outer GFRP reinforcement of RC beams and concrete are described and interpreted. Artificial aging of beams consisted of saline water immersion, salt fogging and cyclic tidal-like action causing degradation on mechanical properties that are reported and examined. Computational modeling of these effects is also preliminarily described, considering post-aged constitutive properties of the component materials and relevant non-linear material properties, to study bond-slip and beam response. Tests to develop a shear Mohr–Coulomb envelope as a rupture criterion on the layers adjacent to the interface are also presented.

Experimental Study of Strengthening for Increased Shear Bearing Capacity

The need for structural rehabilitation of concrete structures all over the world is well known, and a great amount of research is going on in this field. The use of carbon fiber-reinforced polymer (CFRP) plate bonding has been shown to be a competitive method with regard to both structural performance and economic factors. This method consists of bonding a thin carbon-fiber laminate or sheet to the surface of the structure to act as an outer reinforcement layer. However, most research in this area has been undertaken to study flexural behavior. This paper deals with shear strengthening of reinforced concrete members by use of CFRP. Tests on rectangular beams 3.5 to 4.5 m long have been undertaken to study different parameters, such as fatigue, anchorage, and others. The strain field in shear spans of beams simultaneously subjected to shear and bending is also studied. The tests presented also contribute to the existing literature on tests of concrete members strengthened for increased shear capacity.

Failure of a braided stainless steel hose connector

Flexible water hoses are used as line connections from water supply plumbing to fixtures and appliances. The design configuration of these hoses varies; however, a common design involves an elastomeric liner surrounded by an outer reinforcement of braided stainless steel wire. These hoses are subject to rupture in service, traceable to the fracture of the braided wire reinforcement. The mechanism of failure involves localized corrosion of the stainless steel wire braid, a condition arising from the presence of water exterior to the hose. The following case of a ruptured water hose demonstrates this condition.

Frontiers of Pulsed Magnet Design

At the K.U. Leuven Pulsed Field Laboratory, high performance coils with optimized internal reinforcement by fiber composites have been pioneered and continuously further developed. Coils made with soft copper wire and Zylon-epoxy composite have sustained fields up to 75 T. For extended service life, 75 T user coils are made with an inner section of strong micro-composite wire and an outer section of soft copper, with additional outer reinforcement. A system of axial compression has been designed that increased peak field significantly. Based on the results obtained with these coils, an outlook to possible future developments are given. This includes a discussion of new materials such as the multi-composite wire and high strength M5 fibers developed by Magellan.

Why do bridging veins rupture into the virtual subdural space?

Electron microscopic data on human bridging veins show thin walls of variable thickness, circumferential arrangement of collagen fibres and a lack of outer reinforcement by arachnoid trabecules, all contributory to the subdural portion of the vein being more fragile than its subarachnoid portion. These features explain the laceration of veins and the subdural location of resultant haematomas.