土遗址锚固用烧料礓石拌合遗址土浆液龄期性能

Age Performance of Grout Mixed with Calcined Ginger Nuts and Earthen Fabric in Anchoring Conservation of Earthen Sites

为寻求与土遗址更为兼容的锚固灌浆材料,选择烧料礓石与民勤县明长城红沙堡遗址土以1∶1比例拌合的浆液材料,对其结石体进行了不同龄期收缩率、含水率、波速、渗透系数、密度、抗折强度和抗压强度的测定及微观结构变化观测。试验结果表明,结石体在龄期28天的收缩率、波速及含水量基本趋于稳定,而抗折强度和抗压强度28天后仍持续发展,直到龄期90天时保持稳定。微观结构观察结果较好地证明了以上规律。烧料礓石前期水化及后期碳化反应保证浆液早期及后期强度。同时渗透系数及密度与遗址土的相近,保证了结石体与遗址土体的兼容性。研究初步表明,该浆液适宜于土遗址锚固工程中使用。

To find more compatible anchoring grout material,caclined ginger nuts and earthen fabric from Hongsabu site of Ming dynasty Great Wall at Minqin country were chosen with the mixture proportion of1∶1.The properties of grout material including shrinkage,water content,wave velocity,permeability coefficient,density,flexural strength and compressive strength,and photomicrographs were tested or observed.Experimental results show that shrinkage,wave velocity,water content basically keeps stable at a certain value at age of 28 d.Meanwhile,flexural and compressive strength keep rising after 28 dand terminate at90 d.Microscope observation results testify the above phenomenon.Initial stage dominated by hydration guarantees the early strength to further support the anchor ability,and later stage dominated by carbonation provides the possibility of strength increase with age.Similarity of penetration coefficient and density to some extent proves that harden grout is compatible to earth sites.As a conclusion,the studied grout material is basically suitable to anchoring requirement of earthen sites.