Experimental Study On The Performance Of Crack Modified Grouting Material For Rammed Earth Site

Earthen sites are an important part of immovable cultural relics in China.Among the many structural diseases developed in earthen sites,the fracture damage seriously affects the integrity and safety of the structure.In the research of grouting materials,Glutinous rice paste and calcined ginger nuts are both involved in the reinforcement of cracks in earthen sites.In order to explore the grouting materials which are suitable for the crack reinforcement of the earth sites,in this paper,the glutinous rice slurry and the calcined ginger nuts modified site soil grouting materials are taken as the research objects,and the influence of glutinous rice slurry concentration,the amount of calcined ginger nuts,water binder ratio and the admixture on the fluidity,contractility and mechanical properties of the materials are analyzed,and the best ratio based on comprehensive performance is determined.Then the internal structure of the samples is observed by SEM,and the modification mechanism of the materials is analyzed.Based on the above experiments and analysis,the following conclusions are drawn:(1)With the increase of the concentration of glutinous rice slurry,the content of bentonite and calcined ginger nuts,the fluidity of grouting materials decreased,while with the increase of water binder ratio and water reducing agent,the fluidity increased.According to the range analysis of test data,the sensitivity of the glutinous rice slurry concentration to the fluidity of the grouting material is the largest,the water binder ratio,water reducing agent and calcined ginger nuts content are the second,and the bentonite content is the smallest.(2)With the increase of glutinous rice slurry concentration and water binder ratio,the contractility of the sample increased;with the increase of water reducing agent andbentonite,the contractility of the sample decreased significantly;with the increase of sinter content,the contractility of the sample decreased.(3)With the increase of glutinous rice slurry concentration and water reducing agent content,the flexural strength and compressive strength of the sample increase gradually;with the increase of water binder ratio,the flexural strength and compressive strength of the sample increased first and then decreased,and reached the maximum value when the water binder ratio was 0.55;with the increase of bentonite content,the flexural strength and compressive strength of the sample generally increased first and then decreased;With the increase of calcined ginger nuts content,the flexural strength and compressive strength of the samples increases gradually.(4)Based on the comprehensive balance method,it is suggested that the best ratio of grouting materials is 6% glutinous rice slurry concentration,0.55 water binder ratio,1.5% water reducing agent,10% bentonite and 15% calcined ginger nuts.(5)Glutinous rice slurry can regulate the hydration and gasification of two kinds of cementitious materials.SEM scanning showed that the two cementitious materials contained in the calcined ginger nuts,the cementation products formed after the reaction,well bonded to the soil particles,the branched starch dendrite structure arranged the gasification products CaCO3 and the hydration products C-S-H(hydrated calcium aluminosilicate)according to the dendrite rules,better cemented the soil particles,filled the smaller pores,improved the compactness of the slurry,and significantly enhanced the Mechanical strength.