不同古建筑灰浆加固剂的修复效果研究

Repair Effect of Various Consolidants for Ancient Building Lime Plaster

针对古建筑中需原位保护的灰浆,选用磷酸氢二铵(DAP)、正硅酸乙酯和纳米氢氧化钙溶液配制了6种加固剂,从相容性和有效性两方面评估其对灰浆的加固效果.结果表明:综合性能最佳的加固剂为添加5%(体积分数)无水乙醇的0.1 mol/L的DAP溶液;加固后灰浆生成化学性质更稳定的羟基磷灰石矿物,其表面致密性有所提高,色度变化符合文物保护要求,残留N、P元素的风险小,加固剂的相容性好;加固后灰浆的毛细吸水能力、表面黏聚力、动弹性模量及抗压强度均得到显著改善,加固剂的有效性好.

Six kinds of consolidants for the lime plaster that needed in‑situ protection in ancient building were prepared by diammonium phosphate(DAP),ethyl orthosilicate and nano‑calcium hydroxide solution,and their consolidation effects were evaluated by compatibility and effectiveness.The results show that the consolidant with the best comprehensive performance is 0.1 mol/L DAP solution with 5%(by volume)ethanol.The lime plaster consolidated by the above consolidant generates more chemically stable hydroxyapatite mineral,hence its surface density increases,its color changes in line with the requirement of cultural relic protection,and the risk of residual N and P elements is small.It indicates that the compatibility of the consolidant is good.The capillary water absorption capacity,surface cohesion,dynamic elastic modulus and compressive strength of the above consolidated lime plaster are significantly improved,which indicates the effectiveness of the consolidant.