Search

Energetically weak points in thermally insulated building envelopes are formed by thermal breaks that are implemented to structurally connect external balconies to internal slabs. Current thermal breaks comprise stainless steel bars that penetrate the insulation layer and thus cause significant thermal losses. A new thermal break composed of highly insulating aramid and glass fiber-reinforced polymer (AFRP and GFRP) components and aerogel granulate insulation materials was developed and the first prototypes of the load-bearing components were experimentally investigated. The use of AFRP leads to an excellent thermal performance with linear thermal transmittance values of below 0.15 W/m K. The experimental prototype investigations confirmed the targeted ductile failure mode through concrete crushing in the component–concrete interfaces. The serviceability limit state conditions are met for a targeted balcony cantilever span of 4.0 m. The material-tailored components can be manufactured by fully automated processes such as filament and tape winding and pultrusion to economically produce large quantities within a short time. [ABSTRACT FROM AUTHOR]

The objective of this article was to experimentally evaluate timber–concrete composite beams in two different situations – with and without glass fiber reinforced polymer (GFRP). Four full-scale composite beams (5.4 m in length) were produced, two of which had reinforcement (nominal thickness of 10 mm) and two with no reinforcement. The fiberglass reinforcement was formed from the impregnation of unidirectional fiberglass cloth – effective thickness of 0.5 mm – with epoxy resin. The connection system consisted of steel hooks inclined at 45 degrees, bonded with epoxy adhesive to the holes previously drilled on the wood, whose apparent density at 12% moisture content was 0.79 g/cm 3 . The reinforced timber–concrete composite beams tested had performance efficiency of 79% and average rupture strength of 142.5 kN. Finally, the reinforced timber–concrete composite beams were analytically evaluated using the proposed method in Eurocode5, showing reasonable agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Abstract: In the last decades, FRP composites have been widely used for constructing entire civil structures. One of the challenging issues for building with pultruded FRP composites is understanding the behaviour of bolted joints. In this paper, the results of a numerical analysis performed on different types of bolted composite joints with different geometry and subjected to tensile loads are reported. The aim of this study is to examine the distribution of shear stresses among the different bolts by varying the number of rows of bolts as well as the number of bolts per row. The study also considers the presence of variable diameter washers and their influence on the bearing stresses of composites with different fibre orientations. For verification of the validity of the analytical models, numerical results are compared to experimental results reported elsewhere. The results of this study showed that in multi-bolt joints, the load is not distributed equally due to varying bolt position, bolt-hole clearance, bolt-torque or tightening of the bolt, friction between member plates and at washer-plate interface. The results also indicated that in the presence of washers, the stress distributions in the fibre direction, varying fibre inclinations, are decreasing for each value of washer pressure. [Copyright &y& Elsevier]

Abstract: This paper focus on the design of a GFRP truss-like structure for dismountable bridges with maximum span of 30m. The bridge structure is composed of a deck supported by prestressed trussed beams which are mounted by assembling GFRP tubular profiles and steel joints with bearing type connections. Experimental tests were carried out on short profiles to determine their compressive strength at the connections and on two 1:2.3 reduced models of the trussed beam structure: a short 1.3m span cantilever beam and a 13.0m span simple supported beam. The main results obtained from the performed experimental tests on short profiles and on the cantilever beam are presented herein. It is shown that a non-linear behaviour can be generated on the trussed cantilever beam by decompression of tubular members and that collapses are induced by buckling of diagonal members. [Copyright &y& Elsevier]