Study On Anti - Frosting Technology Of Concrete Lining With High Moisture Content

Many domestic existing channel lining projects have appeared different degrees of frost heaving damage, especially those in the permafrost regions of northeast China and the seasonal frozen soil area of north and northwest China. The frost heaving damage of channel lining projects not only directly effected the project benefits, but also increased the costs and the numbers of repair. So, it is necessary to research the frost heave resistance technology of channel lining projects.0# crystal glue is a kind of organic polymer additives that is developed for the production of cement grouting material. The property of high early strength, automatic flow, non-shrinkage, anti-segregation and low temperature application can reduce the frost heaving damage of channel lining projects.This paper regarded the control measures of frost heaving damage for channel concrete lining in the middle-leg of the South-North project as the key research object, based on the current research results and relevant specification. Firstly, this paper did indoor experiments with concrete added 0# crystal glue and ordinary concrete, to research the influence and improvement effect of 0# crystal glue for frost resistance, anti-permeability and strength characteristics of concrete. Then this paper regarded the SG2 section of main canal in the middle-leg of South-North project as the substance object of study and did outdoor prototype experiments based on engineering practice. This paper also researched the influence of the channel soil and groundwater on the frost heave of concrete. Finally, the data obtained in the experiments were used in the thermal-stress analysis, the following conclusions are drawn:(1)Compared with the ordinary concrete, the frost resistance, flexural toughness anti-permeability and the microstructure of concrete added 0# crystal glue have been significantly improved.(2)The pore water pressure that is on channel lining added 0# crystal glue is smaller than the ordinary one and the ability for concrete lining added 0# crystal glue to adapt to the structure deformation is stronger than the ordinary one.(3)0# crystal glue has little or no effect on the distribution of lining’s temperature filed, but has reduced the strain of channel concrete lining.In conclusion, 0# crystal glue can effectively improve the property of frost heave resistance for concrete and its practicability is better. The success of the experiments can provide experience for the channel lining projects in high moisture content section of the middle-leg of the South-North project and reference for the similar engineering design and construction.