A method for detecting corrosion of concrete sewage pipes

Abstract

The invention relates to a corrosion detection method for a concrete sewage pipe, including the steps of: 1) selecting a basic plane, and placing a concrete sample piece in a coordinate plane matchedwith Photogrammetry imaging technology, and photographing the sample piece from five preset directions; 2) injecting sewage into a main chamber of the pipe, and feeding H2S; 3) during corrosion period, performing sampling at regular intervals to detect pH value, type and concentration of sulfur in corrosion products, appearance and component of the corrosion products, types of microorganisms, etc;4) after the corrosion finished, photographing the sample piece; 5) according to the relative distances from points on the surface of concrete to the edges of the basic plane where an epoxy resin / stainless steel framework is located, respectively establishing three-dimensional models of the surface of concrete before and after corrosion; 6) acquiring concrete corrosion rate, represented by heightchange, by means of Photogrammetry software; and 7) according to the three-dimensional models, calculating change of surface area of the concrete and calculating H2S absorption rate, thus indirectlyreflecting corrosion degree of concrete. The method achieves high-effective and controllable researching on corrosion of the concrete sewage pipe under laboratory conditions, and greatly improves convenience and operability of the test.

Description

technical field [0001] The invention belongs to the technical field of detection methods for simulated pipeline devices, and mainly relates to a corrosion detection method for concrete sewage pipes. Background technique [0002] The municipal drainage pipe network is an important urban infrastructure, which is of great significance to the development and construction of the city, the improvement of people's living standards, and the maintenance of the ecological environment. Pipe network corrosion seriously affects the safety of urban water delivery. On the one hand, the release of corrosion products affects the quality of water delivery. On the other hand, the accumulation of corrosion products on the pipe wall will cause a decrease in water delivery capacity, an increase in energy consumption, and even pipe bursts. polluted environment. Gravity self-flowing concrete pipe (partial flow) is a typical drainage pipe, and its corrosion problem is extremely serious under the ac...

AI Technical Summary

Problems solved by technology

Among them, under the action of corrosive gas with high humidity and high concentration of hydrogen sulfide, corrosion is most likely to occur at the top of the pipe in the concrete gravity tube and at the sewage interface, causing the original calcium silicate hydrate and calcium hydroxide to be transformed into ettringite and gypsum. It is a main corrosion product with loose structure and low mechanical strength, which is prone to damage, ground subsidence, sewage leakage and other accidents, causing serious environmental pollution

However, most domestic and foreign studies on the corrosion of concrete sewage pipelines are limited to qualitative sampling and analysis of corrosion products on the inner wall of active pipelines, which is difficult and uncertain in sampling.

Existing research is difficult to achieve a controllable corrosion test under laboratory conditions to simultaneously simulate the corrosion situation at the pipe top and sewage interface in the actual sewage pipeline, and then quantitatively characterize the corrosion phenomenon, deeply understand the corrosion mechanism, and comprehensively explore anti-corrosion measures

Images