142 Table 2.Results of embedding tes Evaluation method Parallel to the grain Perpendicular to the grain Mean (MPa) CV(%) Mean (MPa) Cv(%) 5%Embedding strength 飞级助1110 6500 289T9 edding strength 6068 防纸级k10 87889 was obtained from the experimental an ular to the grain regardless of dowel diameter for practical purposes.It was that obvious that the 5mm embedding strength perpendicular to he er ng strength m constant me the strengths parallel to the grain were almost constant regar grainpcpCndiCularoienrooeachdoNeldia less of dowel diameter.which agreed with the latter study. eter.The ratio for the 5%embedding strength was almost142 Table 2. Results of embedding test Evaluation method Parallel to the grain Mean (MPa) CV (%) Perpendicular to the grain Mean (MPa) CV (%) 5% Embedding strength d = 8mm Total 26.7 17.1 14.6 17.7 L90 26.8 8.42 15.0 10.8 L100 25.1 11.6 13.5 14.7 Lll0 28.8 23.3 15.3 20.8 L125 25.9 15.1 14.4 19.4 d = 12mm Total 35.4 10.5 14.2 15.5 L90 36.4 9.81 14.1 8.84 L100 35.6 12.0 14.2 19.5 Lll0 33.6 7.43 14.0 15.1 L125 36.2 11.0 14.7 15.8 d = 16mm Total 32.6 13.2 14.3 17.3 L90 28.4 10.4 12.7 16.8 L100 31.3 7.81 14.5 13.6 Ll10 33.9 9.61 14.2 20.1 L125 36.7 9.74 15.9 10.7 d - 20mm Total 33.9 11.2 13.3 20.3 Lg0 31.9 8.18 12.5 14.6 L100 31.9 9.51 11.8 17.1 Lll0 35.1 7.18 13.3 12.3 L125 36.6 11.9 15.4 21.8 5 mm Embedding strength d = 8mm Total 34.2 10.8 22.4 16.9 L90 33.8 6.26 21.8 10.4 LI00 32.9 6.11 21.6 16.7 Lll0 35.3 14.1 23.6 18.7 L125 34.7 11.9 22.5 18.2 d = 12mm Total 37.1 10.6 18.6 17.4 L90 37.3 9.83 17.6 il.9 L100 37.0 12.8 18.7 19~0 Ll10 36.0 7.43 18.5 I6.9 L125 38.3 11.0 19.7 18.1 d = 16mm Total 33.8 12.9 17.9 16.1 L90 29.6 11.6 15.4 16.3 L100 32.4 6.98 18.1 10.1 Lll0 34.7 9.42 !7.9 116.1 L125 38.5 7.84 20.3 10.1 d = 20mm Total 34.3 11.1 15,3 20.9 Lg0 32.5 7.63 14.5 14.2 L100 32.5 9.61 13.7 17.7 Lll0 35.6 7.64 15.5 14.6 L125 37.0 12.0 17.7 22.9 derness ratio of 4, the effects of bending the dowel on the load-displacement curve cannot be ignored. The regression equation of the 5 % embedding strength parallel to the grain was obtained from the experimental results with dowels 12, 16, and 20mm in diameter, excluding those with dowels 8mm in diameter. Whale et al. 5 reported that the embed￾ding strength parallel to the grain decreased as the dowel diameter increased. Hirai 3 and Harada et al. 9 reported that the embedding strength was almost constant regardless of dowel diameter. In our study, the 5 % and 5 mm embedding strengths parallel to the grain were almost constant regard￾less of dowel diameter, which agreed with the latter study. For conditions perpendicular to the grain, numerous stud￾ies 3'4'6'9 reported that embedding strength decreased as the dowel diameter increased, which may be caused by the effects of crack propagation. 3 The 5% embedding strength perpendicular to the grain decreased slightty as the dowel diameter increased but could be considered almost constant regardless of dowel diameter for practical purposes. It was obvious that the 5 mm embedding strength perpendicular to the grain decreased as the dowel diameter increased. Figure 6 shows the embedding strength parallel to the grain/perpendicular to the grain ratio for each dowel diam￾eter. The ratio for the 5% embedding strength was almost