钙基液态水硬性加固剂用于潮湿土遗址的加固保护

Consolidation of historical earthen sites under moisture circumstance using calcium-based hydraulic consolidant

通过对钙基液态水硬性加固剂的研制,对潮湿环境土遗址的加固保护进行了探索性研究。X射线衍射(XRD)和扫描电镜(SEM)分析结果表明,已成功制出了潮湿土样水硬性加固所需的纳米材料。同时,研究发现,氢氧化钙在650℃下用马弗炉煅烧1.5 h后,可得到直径约50 nm、长度约200 nm的针状二次生石灰;这种二次生石灰经水消化后,会成为粒径在200～300 nm左右、大小十分均匀的扁平椭圆状纳米氢氧化钙颗粒;氧化钙在密封陈化一段时间后,也可使氢氧化钙的粒径达到纳米级。土样加固试验的结果显示,纳米石灰的乙醇分散液的渗透性优于分析纯氢氧化钙,钙基水硬性加固剂对潮湿土样的加固效果较为明显,有望成为一种适合于潮湿环境土遗址加固的新型材料。

On the basis of preparation and characterization of calcium-based hydraulic consolidant,this paper makes a preliminary study of consolidation conservation of historical earthen sites under moisture circumstance.Analytic results of scanning electron microscope and X-ray diffractometry show that Ca（OH）2 are transformed into a kind of acicular secondary CaO with diameter 50 nm and length 200 nm after being calcined,and this nano-sized secondary CaO are transformed into oval plate-like Ca（OH）2 with size 200-300 nm after being slaked.Meanwhile,research results indicate that calcium hydroxide crystals undergo both substantial size reduction and clear morphological change,developing nanometer,plate-like and acicular crystals upon aging.Results of consolidation experiment of moist earthen samples reveal that permeabilities of nanometer lime-alcohol dispersions are superior to that of analytically pure Ca（OH）2-alcohol dispersions,and consolidation effects of calcium-based hydraulic consolidant are obvious.It is possible that calcium-based hydraulic consolidant will become a new consolidation material used for conservation of historical earthen sites under moisture circumstance.