AbstractThe use of Fibre Reinforced Polymers (FRP) has recently become widespread in the construction industry. However, some drawbacks related to premature debonding of the FRP composites from the bonded substrates have been identified. One of the solutions proposed is the implementation of mechanical anchorage systems. Although some design guidelines have been developed, the actual knowledge continues to be rather limited. Thus, designers and researchers have not yet achieved any consensus on the efficiency of any particular anchor device in delaying or preventing the premature debonding failure mode that can occur in Externally Bonded Reinforcement (EBR) systems. This paper studies the debonding phenomenon of FRP anchoring systems with a linear variable width, with a numerical analysis based on the Distinct Element Method (DEM). Combined systems with constant and variable width are also discussed. The FRP-to-parent material interfaces are modelled with a rigid-linear softening bond–slip law. The numerical results showed that it is possible to attain the FRP rupture force with a variable width solution. This solution is particularly attractive when the bonded length is shorter than the effective bonded length because the strength of the interface can be highly incremented.
Micaelo, Rui, Jaime Ribeiro, Maria Azevedo, and Nuno AzevedoHMA Compaction Study: Two Different Approaches. 11th ISAP – International Conference on Asphalt Pavements. Nagoya, Japan: ISAP, 2010.
There are many different ways to reduce the construction industry's impact on environment. The incorporation of waste in the fabrication of construction materials may be beneficial for both the waste management sector and the construction industry. The aim of this research was to investigate the use of three different waste materials (construction and demolition waste, brick powder and fly ash) as filler in asphalt mixtures. Limestone filler was used as reference material. The materials were characterized in terms of their geometrical, physical and chemical properties, and the interaction with bitumen was assessed with two mastic test methods using four different bitumens. The specific surface of waste materials shows a wide-ranging variation due to material specific shape and texture of particles. However, the Rigden voids and bitumen number tests adequately measure the stiffening effect of these materials. The delta ring and ball test results showed there is a good relation with the filler content when the results are affected by the bitumen type. The f/b ratio for a specific bitumen–filler combination can be determined from the maximum filler-to-bitumen ratio and the recommended stiffening increase. The mastics with these waste materials showed strong resistance to water damage.
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