Experimental Research On The Durability And Life Prediction Of The Ordinary Concrete Field Exposure In Xining

Xining is one of the typical saline soil area, due to its special natural environment, there is high sulfate content in saline soil, the weather is cold and dry. Concrete buildings has suffered from serious sulfate attack, seasonal freezing and melting,seasonal drying and wetting in the area, These factors lead to concrete structures destroyed before design working life.In order to effectively study the durability of the concrete in the region, at the same time to estimate the service life of concrete. This article compares the scene of field exposure test and laboratory test. In the area of the durability of the concrete are studied, it also predict the normal service life of concrete and the surplus service life of concrete structures in service.In this article, through the study of the changes of relative sample quality and the relative dynamic elastic, we set up two indexes, relative quality evaluation parameter ω1and relative dynamic elastic evaluation parameters ω2, they can accurate intuitively reflect the degradation process of concrete performance, analyze and evaluate the performance of concrete. But because of ω1，ω2sometimes contradictory, according to the actual circumstance and the changes of ω1，ω2,we set up durability evaluation parameters ω to unified comprehensive durability evaluation of concrete.Using the X-ray Energy Dispersive Spectroscopy, Scanning Electron Microscope and X-ray Diffraction, study on the hydration products and microstructure of magnesium oxychloride cement. We can analyze its formation cause and the effect on the properties of concrete durability.Using durability evaluation parameter, we analysis the different performance of field exposure test and laboratory test to get the fast damage coefficient K with comparing the ω of field exposure test and laboratory test.Through the analysis of the field exposure test of concrete in720days, we can get the simple model to calculate the residual life. It can preliminary predict residual durability life of concrete structure materials in active service.