The Influence Factors Of Cement Mortar Lining Corrosion And The Impact On Water Quality In Water Distribution System

This paper studies the five water quality factors influencing cement mortar lining corrosion, sulfate ion, chloridion, magnesium ion, calcium ion and pH from the perspective of feedwater water quality safety. It also studies silicate digestion condition of cement mortar lining by the function of different water quality by establishing single factor and multi-factor experiment in static state tabulation soak way. At the same time, it detects conventional water quality index at regular intervals, observes the influence on water quality by cement mortar lining corrosion. In addition, preparation of cement mortar test block method is adopted to simulate cement sand lining of real tabulation in order to directly study cement mortar lining corrosion changes by the function of the five water quality factors. It also analyzes the microcosmic feature changes of cement mortar lining. Finally, this paper establishes silicate dissolution model discusses the influence on cement mortar lining corrosion by these five water quality factors based on experimental data by using statistical method. We get the following achievements from the above experimental study.(1) We get the five water quality factors, sulfate ion, chloridion, magnesium ion, calcium ion and pH through the experiment and model from the perspective of water supply water quality, which will have an influence on cement mortar lining.(2) It can be seen that through single factor experiment and observation of microstructure changes of cement mortar test block, sulfate ion and chloridion in high concentration have a severe influence on cement mortar lining corrosion. We can verify the experimental conclusion through correlation analysis that both of them have positive correlation property with silicate digestion.(3) It can be seen that through single factor experiment and observation of microstructure changes of cement mortar test block, sulfate ion and chloridion in low concentration have a severe influence on cement mortar lining corrosion. The conclusion through correlation analysis is in accordance with the experiment and both of them show strong negative correlation. In addition, the acidic water verified by experiment and model is also conducive to the corrosion of cement mortar lining.(4) The multifactor experiment is used to do research on the combined action of these five water quality factors and its influence on cement mortar lining corrosion in order to get close to the real water quality. It is conclude that the water quality with acidity, low hardness, low concentration of chloridion and sulfate ion, its influence on cement mortar lining corrosion is the most serious.(5) Verify the influence on cement mortar lining corrosion by these five water quality factor using full regression, stepwise regression and factor analysis methods. It is conclude that alkalinity has an obvious influence on cement mortar lining corrosion apart from these two water quality factors.