An experimental method for the relationship between carbonization rate of concrete and pore water saturation

Abstract

The invention relates to an experimental method for the relationship between the carbonization speed of concrete and the pore water saturation. In the sodium fluorescein solution, dye the unsaturated part of the pore water in the concrete specimen; cut the dyed concrete specimen in half along the diameter direction; one half of the concrete specimen is dyed with phenolphthalein to measure the carbonization depth, and the other half is placed Measure the saturated pore water depth under ultraviolet light irradiation, and calculate the carbonization speed according to the carbonization depth and carbonization time; replace the concrete specimen, change the carbonization time, and repeat the test to obtain multiple sets of pore water depth data and concrete carbonation corresponding to the pore water depth data. From the speed data, the relationship curve between concrete carbonation speed and pore water saturation is obtained. The invention makes up the blank of the effect of pore water saturation on the carbonization speed of concrete.

Description

technical field [0001] The invention relates to the technical field of concrete material and concrete component analysis, in particular to an experimental method for the relationship between concrete carbonation speed and pore water saturation. Background technique [0002] Since the emergence of reinforced concrete structures in China at the end of the 19th century and the beginning of the 20th century, the application of reinforced concrete in engineering construction has become more and more common. Whether it is bridges, houses or tunnels, a large number of reinforced concrete materials are used. However, reinforced concrete materials are eroded by carbon dioxide, chloride ions and other substances, which reduces their durability and directly threatens the safety and stability of building structures. [0003] The interior of uncarbonized concrete is highly alkaline, and the pH value is generally around 12.5. In this environment, a passivation film will form on the surfac...

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Problems solved by technology

At present, the test of the influencing factors of concrete carbonation rate is such as the patent No. CN104568723B discloses a concrete accelerated carbonation test method and device under the environment condition of groundwater containing aggressive carbon dioxide, which studies the influence of high-concentration carbon dioxide groundwater on the carbonation rate of concrete; For example, the patent No. CN103616382B discloses a kind of instrument and method for detecting concrete carbonation and chloride ion penetration depth of in-service electric poles. What it studies is the influence of chloride ion penetration depth on concrete carbonation, but for the impact of concrete pore water saturation on concrete Little research has been done on the effects of carbonation

[0005] Xu Bing, Xu Gang, Yang Yahui and others disclosed the method of the influence of pore water saturation on the carbonation characteristics of concrete in the literature of "The Effect of Pore Water Saturation on Carbonation Properties of Concrete". The research method is to prefabricate different pore water saturation Then carbonize these test blocks, and then analyze the influence of concrete pore water saturation on concrete carbonation. However, when prefabricating test blocks with specified pore water saturation, the pore water saturation is greatly affected by the humidity in the oven. The pore water saturation of the prefabricated test block deviates greatly from the design value, so the accuracy of subsequent tests is relatively low

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