利用天然树脂加固饱水古木的试验研究

Study on reinforcing water-archeological wood with natural resin

用天然树脂(氢化松香和漂白紫胶)对61根海门口遗址饱水古木进行加固,使其满足后续的运输、贮存及展示要求,同时也可为其他大型饱水古木的加固保护提供宝贵经验。加固完成后用其中一根具有代表性的古木进行加固效果评价。加固效果评价方法包括:加固收缩率、脱水收缩率、最大含水率、基本密度、顺纹抗压强度、疏水性、耐菌腐性能以及天然树脂脱出试验。结果表明:加固后古木颜色及纹理与现代健康材接近;加固收缩率横向为5.15%,纵向1.68%;古木的基本密度从0.16 g/cm3提高到0.23 g/cm3;最大含水率从578.68%下降到367.56%;顺纹抗压强度从3.67 MPa增加到16.70 MPa;加固古木三切面的表面接触角都明显增大,说明其疏水性明显增强;耐菌腐试验中天然树脂加固古木质量损失率为6.41%,属强耐腐木材;浸入古木内部的松香及紫胶可以用乙醇通过浸泡的方式重新脱出。

The water archeological wood at 61 Haimenkou sites were reinforced with natural resins （hydrogenated rosin and bleached shellac） to meet the requirements of subsequent transportation, storage and exhibition. This paper provides valuable technology for protecting other large volume of water areheologieal woods. A typical water archeological wood was used to evaluate the reinforcement effect, including the reinforcement shrinkage, dehydration shrinkage, the maximum moisture content, basie density, compressive strength parallel to grain, hydrophobie, and decay-resistant properties of fungus. The results showed that the color and texture of the reinforced archeological wood were close to the modem health wood; the horizontal and vertical reinforcement shrinkage were 5. 15% and 1.68%, respectively; the basic density in- creased from 0. 16 to 0. 23 g/em3 ; the maximum moisture content decreased from 578. 68% to 367.56% ; the compres- sive strength parallel to grain increased from 3.67 to 16.70 MPa; the surface contact angle of the three facets increased significantly, which showed that the hydrophobicity of reinforcement ancient enhanced significantly. The mass loss rate of reinforced ancient wood was 6.41% in the decay-resistant test, which belongs to decay-resistant timber. It was also found that the rosin and shellac immersed in archeological wood could be dissolved out by the ethanol soaking.