Study on deteriorarion mechanism and protective measures of historical stone monuments

(1)研制了测定砖和砂浆保水曲线和非饱和导水系数的实验装置。历史砖建筑和纪念碑用砖和砂浆的保水曲线和导水率。测试结果表明，在一定的吸水率下，砂浆的含水率高于砖的含水率。砂浆的非饱和导水率大于砖。利用实测资料，采用有限元软件计算了砖砌古建筑及古建筑群的水分状况。(2)对取自历史遗址的石头、砖和压实土的物理性质，如粒度分布、孔径分布和比表面积进行了测量，并与材料的劣化有关。(3)研制了一种热时域反射探头，用于测量含水率、电导率和热导率。这些传感器用于砖和土墙。实测数据表明了传感器的有效性。(4)为了研究日本土墙的劣化机理，在北海道历史村建造了模型土墙。将时域反射传感器埋入土中，测量土中体积含水量的变化。利用德国德累斯顿工业大学开发的DELPHIN 4程序，利用气象资料、土壤材料数据，对干燥过程中土墙的含水量和水流进行了数值计算。计算结果与实测结果吻合较好。这些结果表明DELPHIN 4程序用于测定多孔材料含水量的有效性。由于必须采用非破坏性的方法来获取文物的物理特性，因此模拟技术对于这些与文物保护相关的研究是非常有效的。

(1) Experimental apparatuses were developed to measure moisture retention curve and unsaturated hydraulic conductivity of brick and mortar. The moisture retention curve and hydraulic conductivity of brick and mortar used for historical brick buildings and monuments. The measured results showed that the water contein is higher for mortar than that for brick at a given water suction. The unsaturated hydraulic conductivity is higher for mortar than that for brick. The water regime of historical brick buildings and monuments was calculated with finite element method software using measured data.(2) Physical properties, such as grain size distribution, pore size distribution and specific surface area of stone, brick and compacted soil taken from historical sites were measured and related to the deterioration of the materials.(3) A thermo-TDR probe was developed to measure the water content, electrical conductivity and thermal conductivity. These sensors were used for brick and earthen wall. The measured data showed the validity of these sensors.(4) In order to study the deterioration mechanism of Japanese earthen wall, model earthen wall was build in Historical Village of Hokkaido. The TDR sensors were embedded in the earthen wall and the change of volumetric water content was measured. A numerical calculation of water content and water flow of earthen wall during the drying process was carried out with meteorological data, material data of soil by DELPHIN4 program developed by TU Dresden. The calculated results corresponded well with the measured ones. These results showed the validity of DELPHIN4 program for determining water content in the porous materials. Since it is necessary to use non-destructive method to obtain physical properties of the cultural properties, the simulation technique is quite effective for these studies related to the conservation of cultural properties.