Engineering Characteristics Of The Repair Material Applied To Pagoda-sites In Baisikou

The pagoda-sites in Baisikou, Ningxia Hui Autonomous Region were discovered in 1999 and then 62 pagoda foundations were carried out archaeological excavations. The pagodas were built from the Western Xia to the Yuan period as burials of eminent monk. It’s an important part of the royal temple and a well-known Buddhist sanctuary in Western Xia. The pagodas, through centuries, just remain the foundations in very bad condition. The pagoda foundations are of such high artistic value that it’s the object reference of Western Xia for the research of the politics, the style of the architectural and the Buddhist culture. According to field investigation, the pagoda foundations suffer different kinds of serious disease, such as brick efflorescence, mortar pulverization. At the same time, contrasting the photos of the pagoda foundations took in 2002 and2014, the pagoda foundations change a lot and damage greatly. In order to prevent the disease aggravating and preserve the culture of Western Xia the pagoda-sites must be repaired and protected immediately.The research takes the mortar between bricks of the pagoda foundations as the key object. In order to repair the mortar pulverization, the engineering characteristic of the traditional sticky rice mortar and new SH mortar are studied respectively. Conclusions are drawn as following:(1) That the basic ratio of lime-soil is 2:8, which is mixed with tiny hemp fiber is determined. Through the consistency control of mortar, the water cement ratio of different mortar is determined. The tested samples are divided into two categories, which are cube test block and blue brick-mortar composite samples. The cube test blocks go through 0/5/10 dry-wet freeze-thaw cycles, and the composite samples go through 20 dry-wet freeze-thaw cycles. The durability of SH mortar is better than sticky rice mortar.(2) Experiments are carried out to get the physical properties of the mortar, such as workability, Shrinkage and water absorption. The test results are as follows. The water retention of the several kinds of mortar is higher than 91% and all reach the designed requirement. The water retention of 1% sticky rice mortar is the best which reaches 95%. The water absorption of sticky rice mortar decreases with the increase of the concentration of sticky rice juice and the minimum is 21.37%. The water absorption of SH mortar is less affected by the concentration of the concentration of SH and it is steady at around 29%. The shrinkage of all the mortar is less than0.4%. Hemp fiber can effectively reduce the shrinkage of mortar. The shrinkage of 3% sticky rice mortar is 0.18% which is the lowest.(3) Experiment study has been made on the mechanical properties of the mortar such as compressive strength, bonding strength and shearing strength. The test results are as follows. The wave velocity and compressive strength of sticky rice mortar increase with the increase of theslurry concentration of sticky rice juice. On the other hand, the laws of the SH mortar is opposite.3% sticky rice mortar presents brittle failure. There is positive correlation between blue brick-mortar composite samples and concentration. The bond strength and shear strength of the SH mortar are significantly higher than that of the sticky rice mortar. The durability of SH mortar is better than sticky rice mortar. Synthesizes mechanical properties and physical properties, the best is 1% SH mortar.