木ダボによる大断面円柱材の縦継ぎ（第１報）被着材含水率の木ダボ引抜耐力への影響

引抜型接合具

The application of glued-in hardwood dowels to end-jointing of large section column timbers was considered. In this study, pull-out tests were made using sugi (Cryptomeria japonica) and 12mm diameter dowels (Acer saccharum) to investgate the effect of moisture content (MC) of the wood member on withdrawal properties. Withdrawal strengths and slip modulus by pull-out tests tended to decrease as MC increased. The gradient of regression line between the moisture content of the wood member and withdrawal strengths and slip modulus for double dowels smaller than that for single dowels. Although differences between average withdrawal strengths MC≦20% and average withdrawal strengths of MC >20% for single dowels were significant, the results for double dowels were not significant.