Editorial

Abstract

The first four papers in this themed issue are drawn from contributions presented at the fourth biennial Advanced Composites in Construction (ACIC) conference, held in Edinburgh in 2009. A wide range of sessions encompassed many exciting construction application areas including the use of fibrereinforced polymers (FRPs) as internal reinforcement for concrete, FRP stay-in-place formwork and sandwich panels, allcomposite structures built with FRP profiles, and the FRP strengthening of concrete, steel masonry or timber structures. Important aspects of the business case for the use of advanced composites were also discussed and case studies of structures in service provided the opportunity for users to share their experience. These studies were complemented with the presentation of research investigations to address some of the challenges associated with FRPs, such as the durability under environmental conditions, the performance in fire and elevated temperatures, and FRP to FRP connections.For all-composite structures, the connection details are a source of local stress concentrations which can lead to premature failures. Bolted, adhesive bonded, or combined bolted and bonded joints have been proposed as connections for FRP profiles. In bolted joints, steel bolts are commonly used and the contributions of Mottram and Zafari (2011), Turvey (2011a) and Oppe and Knippers (2011) investigate the mechanics of this type of connection detail. Adhesive bonded splice joints are then the subject of a further paper by Turvey (2011b).Shear is an important load transfer mechanism in FRP to FRP joints and the paper by Mottram and Zafari (2011) presents a new test method to help predict the bearing resistance of an FRP connection with steel bolts. This failure mode is of particular interest since bearing can provide some damage tolerance and hence is favoured. To calculate the bearing failure load, design codes require an FRP material parameter known as the pinbearing strength. However, existing test methods to ascertain pin-bearing strengths show wide variations in approaches and definitions of failure. To address this, the authors propose a new test method where a cylindrical steel pin is compressed into a circular notch in an FRP plate aligned vertically. New results for the pin-bearing strengths associated with loading in different orientations relative to the pultrusion direction, and the effect of the ratio of the pin diameter to plate thickness are reported.In Turvey (2011a), the main focus is the condition where bolts are loaded in tension, such as in FRP column-base joints. To model these effects, a comprehensive experimental programme was undertaken where a single steel bolt was pulled through a pultruded FRP plate. The bolt diameter, plate end support conditions (clamped or free) and plate dimensions were varied, and the influence of these variables on the transverse stiffness, damage loads, ultimate failure loads and failure patterns was then highlighted. In general, it was found that the transverse stiffness, the dam...