Basalt FRP Spike Repairing of Wood Beams
This article describes aspects within an experimental program aimed at improving the structural performance of cracked solid fir-wood beams repaired with Basalt Fiber Reinforced Polymer (BFRP) spikes. Fir wood is characterized by its low density, low compression strength, and high level of defects, and it is likely to distort when dried and tends to fail under tension due to the presence of cracks, knots, or grain deviation. The proposed repair technique consists of the insertion of BFRP spikes into timber beams to restore the continuity of cracked sections. The experimental efforts deal with the evaluation of the bending strength and deformation properties of 24 timber beams. An artificially simulated cracking was produced by cutting the wood beams in half or notching. The obtained results for the repaired beams were compared with those of solid undamaged and damaged beams, and increases of beam capacity, bending strength and of modulus of elasticity, and analysis of failure modes was discussed. For notched beams, the application of the BFRP spikes was able to restore the original bending capacity of undamaged beams, while only a small part of the original capacity was recovered for beams that were cut in half.
Flexural bending behaviour of built-up glulam box-selection beams at ambient and elevated temperatures
................................................................................................................................... iii Acknowledgement .................................................................................................................... v List of Tables ............................................................................................................................ x List of Equations ...................................................................................................................... xi List of Figures ......................................................................................................................... xii Nomenclature .......................................................................................................................... xv Chapter
Suppressed Light Emission of the Reaction Zone in Detonation
THE detonation of high explosives in water can be photographed with an open camera and a flash light as the explosive gases do not emit light. The method has been used1 to investigate the spread of shock waves and explosive gases, and to investigate the initiation by shock waves2. We have found that it can be used also in certain gases such as butane and propane. The method is not suitable, on the other hand, for explosives with two levels of detonation velocity in the case of low velocity. A great part of the reaction then occurs after the reaction zone has passed and the expanding explosive gases are very luminous even in water.