细菌诱导矿化保护历史建筑遗产的机理及效果

MECHANISM AND PERFORMANCE OF REMEDIATION FOR HISTORIC BUILDINGS BY BACTERIALLY INDUCED MINERALIZATION

为了研究细菌诱导碳酸钙在大理石、混凝土基材表层矿化沉积形成的人工层对基材加固保护的机理及性能,用X射线衍射、扫描电镜、压汞仪及超声波研究分析了矿化晶体物相,矿化层生长,沉积晶体对基材孔隙的影响以及矿化层黏结与保护效果。结果表明:矿化晶体为方解石和球文石;Ca2+源影响碳酸钙矿化沉积晶相,细菌在晶体矿化沉积过程中充当成核位点,且晶体均匀生长在基材表面;沉积致使试样孔隙率减少,但对孔隙分布无显著影响;矿化层与基材可以形成有效黏结。

To study the mechanism and performance of protection for historic buildings conducted by bacterially induced carbonate mineralization on the surface of marble and concrete as matrix, the composition and growth of the mineral deposited on the matrix, the porosity or pore size distribution of the matrix and the efficiency of protection were analyzed by X-ray diffraction, scanning electron microscopy, mercury intrusion porosimetry and ultrasonic test. The results show that the phases of mineral crystal are calcite and vaterite, and the calcium source has an effect on the phase of calcium carbonate mineralization and precipitation. Bacteria act as nucleation sites in the course of precipitation of the mineral crystallization, and the crystal is deposited uniformly on the surface and subsurface of the matrix. The precipitation has no significant effect on the pore size distribution of the matrix, but results in a decrease of porosity, and mineral crystals are strongly attached to the substratum. Bacterial mineralization for remediation of historic buildings can be an ecolozical and novel alternative to traditional techniaues.