Experimental method for a relationship between concrete carbonization speed and pore water saturation

Abstract

The invention relates to an experimental method for a relationship between a concrete carbonization speed and pore water saturation. The experimental method comprises the following steps: manufacturing a concrete test piece and carrying out maintenance and pretreatment; setting carbonization time, and enabling the concrete test piece to be subjected to manual accelerated carbonization; soaking theconcrete test piece in a sodium fluorescein solution, and dyeing the unsaturated part of the pore water in the concrete test piece; splitting the dyed concrete test piece in a half-and-half manner along the diameter direction, dyeing one half of the concrete sample with phenolphthalein to measure the carbonization depth, putting the other half of the concrete sample under irradiation of an ultraviolet lamp to measure the saturated pore water depth, and calculating the carbonization speed according to the carbonization depth and the carbonization time; replacing the concrete test piece, changing the carbonization time, repeating the test to obtain multiple groups of pore water depth data and concrete carbonization speed data corresponding to the pore water depth data, and obtaining a relation curve of the concrete carbonization speed and the pore water saturation. The blank of influence of the pore water saturation on the concrete carbonization speed is filled up.

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 rate and pore water saturation. Background technique [0002] Since the appearance of reinforced concrete structures in China at the end of the 19th century and the beginning of the 20th century, the use 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 corroded by carbon dioxide, chloride ions and other substances, resulting in reduced durability, which directly threatens the safety and stability of building structures. [0003] The interior of uncarbonated concrete is highly alkaline, and the pH value is generally around 12.5. In this environment, a passivation film will be formed on the sur...

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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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