Presented paper is focused on repairing of wooden elements by Beta joints reinforced with carbon, steel or beech rods, and on comparing the efficiency of these joints with traditional carpentry joints. In model laboratory experiments have been determined the bending strength (fm) and the modulus of elasticity (E) of control or original elements (fm-Control; Eo) from Norway spruce (Picea abies Karst. L.) with dimensions of 1100x80x40 mm (length x height x width), and subsequently of the repaired elements (fm-R; ER), as well. The repair of elements was accomplished in their ends with supplementary prisms:- a) from the original spruce elements; b) from the epoxy-wood composite. Fixation of the basic and the supplementary prisms together with rods was secured with epoxy resins Kimitech EP-TX or CHS Epoxy 1200. Elements repaired with carbon rods had the modulus of elasticity increased almost in all situations (ER / E0 = from 0.96 to 1.34):- at using of shorter or longer rods (e = from 200 to 500 mm), - at using of one or two rods, - at putting of rods nearer or farther from the tension zone of elements (10 or 20 mm from bottom). On the other hand, all repaired elements had a lower bending strength in comparison to original ones (fm-R / fm-Control  0.87).

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