滨海某电厂桩基及基础防腐方案浅析

开篇：润墨网以专业的文秘视角，为您筛选了一篇滨海某电厂桩基及基础防腐方案浅析范文，如需获取更多写作素材，在线客服老师一对一协助。欢迎您的阅读与分享！

Binhai a power plant based anticorrosion scheme pile foundation and analysed

of

(guangxi electric power industry survey and design institute, guangxi nanning city, 530023)

[abstract] briefly summarizes the binhai structure concrete structure the reason of corrosion and preventive measures. The binhai a power plant is introduced to anticorrosive plan, for the other similar project to provide certain reference.

[key words] coastal; Concrete structure; Corrosion;

0 introduction

A building in the design use fixed number of year inside, must meet the safety, applicability and durability 3 requirements, the concrete structure building complex environment, durability has had a significant impact on structure, so the concrete structure building antisepsis problem has become a universal and problem of concern [1].

1 the concrete structure building the reason of corrosion

Corrosion of reinforcement in concrete can be induced by two factors:

Is CO2 makes a concrete carbonation, carbon dioxide and concrete calcium hydroxide in the reaction, the generation of substances such as calcium carbonate, the alkaline gradually reduced, disappear even, called it the carbonization of concrete. When buildings in the air or in the environment of carbon dioxide, concrete reinforced, and anti-permeability of shortage, happen carbonation, failure to form stable and dense passivation protective film, thus rebar corrosion.

2 it is chlorine ion (Cl-to produce into steel electrochemical corrosion, the results of scientific studies show that Marine climate led to corrosion of reinforcement in concrete structures damage is the main factor chloride ions into the concrete and rebar surface in gathering, prompting reinforced create electrochemical corrosion. Chlorine ion in the mainly comes from the ocean, sea water is typically 3% of salt, which is mainly chloride (Cl-seawater in the content of about 19000 mg/L. Sea wind, the sea fog also contains Cl-chloride containing more not the same amount of Cl- Therefore, the sea water, sea wind and the sea fog in the Cl-and not reasonable use sea sand, is to influence the durability of concrete construction is one of the main reasons.

2 the concrete structure building anti-corrosion major measures

2.1 improve the thickness of concrete cover and quality

This is to improve the service life of the concrete structure building the most direct, simple and cost-effective method. But cover thickness and not restricted arbitrary increase.

2.2 by high performance concrete

With the durability of the high performance concrete as the primary index, can have the key point to be to ensure the durability, workability, strength, volume stability and economy, etc.

2.3 with concrete inhibitors

The corrosion of reinforcement in concrete, is a kind of electrochemical corrosion, the Yin, anode reaction in the interface of the reinforced electrolyte happen. Inhibitors can participate in and stop the priority two or one of the interface reaction, and can keep for a long time steady state, effectively prevent rust corrosion.

2.4 tu (plating) layer reinforced

The seawater environment of chlorine in cold area of salt in the meat concrete is harmless, corrosion damage of reinforced concrete structures is through the corrosion of reinforcement in the realization of rust bulge. Therefore, if the rebar surface layer is implementing an advance corrosion or corrosion resistant coating (plating) layer to block or isolation Cl-erosion, is the most direct technical measures.

2.5 concrete protection coating

Implementation of the concrete surface coating protection, can prevent or decrease the environmental media intrusion of chlorine ion in. Ground floor coating (closed paint), should have a low viscosity and high penetration ability, and can penetrate in concrete to a closed pore and improve the subsequent coat of adhesion of role.

3 binhai a power plant of groundwater the corrosive

The project of the Ⅱ environment like groundwater type water. According to the water quality analysis results (table 1) and engineering geotechnical engineering investigation report, it is known that the groundwater and the sea of concrete and steel structure all have strong corrosive. Due to the relatively shallow buried underground water level, the foundation soil infiltration by groundwater or immerse, its corrosive and groundwater are the same.

Table 1 factory water quality analysis corrosive medium table test results

Sample number SO

(mg/L) Cl-

(mg/L) Mg2 +

(mg/L) total mineralization degree

(mg/L) PH

Value aggressive CO2

(mg/L) water samples

type

CS-1-415.94 2949.44 193.34 5294.52 3.98 3.02 pollution well water

CS-2 2127.56 9472.24 386.69 18537.86 7.85 8.57 the sea water

CS-3 2414.86 20986.4 1031.17 37277.61 8.35 0.00 activities sea water

CS-4 32.28 124.78 3.87 279.94 6.92 1.21 clean water from the well

4 underground concrete structure corrosion environment level judgment

According to the water quality analysis results, the comparison "industrial building anti-corrosion design specification of GB50046-2008 in the related regulations, magnesium salt (Mg2 +), sulfate (SO) content are no more than 1%, the corrosion level for moderately corrosive, PH value except CS-1 the water are larger than 4, the corrosion level also for moderately corrosive, considering the CS-1 for water pollution Wells, the representative is bad, SO through the PH value judgment for moderately corrosive corrosion level; Control the geotechnical engineering standard "GB50021-2001 in the related regulations, sulphate content (SO) < 3000 mg/L, magnesium salt (Mg2 +) content < 3000 mg/L, total salinity < 50000 mg/L, aggressive < 15 mg/L, PH value > 4, the corrosion level for weak corrosive,; But according to chlorine ion (Cl-content discrimination, long-term immersion conditions to the corrosion level for weak corrosive, alternating wet conditions for strong corrosive. Considering the depth of pile foundation under a relatively stable range mainland water level, concrete in saturated water state, the oxygen condition is poor, relatively slow steel corrosion, so the pile foundation of concrete and reinforced the corrosion level in moderately corrosive consideration; And other underground structure for shallow, the scope affected by external environment of groundwater, the alternating wet conditions, so near to groundwater based range of concrete and reinforced the corrosion level according to the strong corrosive consideration.

5 underground concrete structure corruption scheme

5.1 the anticorrosion scheme pile foundation

The project by the bored perfusion pile foundation rock-socketed pile. Filling pile into the hole slurry supporting, its no hardening in by direct contact with the media, so in pouring concrete piles will into groundwater. At this time, must be taken on pile body reinforced can direct protection measures. Considering the groundwater on the corrosion of the pile foundation for medium corrosion and corrosion mainly by sulfate (SO) plays a main control function, chloride ion (Cl-on secondary control effect, in this paper, the pile foundation engineering of concrete and reinforced the main principle of corrosion are as follows:

(1) pile advocate muscle of the concrete cover depth for 75 mm;

(2) the strength grade of concrete pile for C35, water cement ratio than 0.45, anti-permeability level S10;

(3) the pile of sulfate Portland cement, cement contents quartile 360 kg/m ³, the largest concrete chloride ion content is 0.1%, the cement clinker aluminum acid calcium content in the three must be controlled in the range of 6% ~ 12% inside;

(4) per cubic concrete mixing and NF-Z type corrosion inhibitors for not less than 12 kg (dry weight);

(5) fine aggregate concrete pile should use clean in sand, not the sea sand; Coarse aggregate limiting grain size should be less than 35 mm;

(6) as water shall not using the seawater, should use the urban water supply system of drinking water, as the water content of chlorine ion should be less than 200 mg/L;

5.2 basis of pile caps is anticorrosion scheme

Because of the foundation soil and water underground corrosion level for strong corrosive, and chloride (Cl-plays a main control function, sulfate (SO) on secondary control function [2]. In this paper, the engineering foundation pile caps is anti-corrosion of concrete and reinforced the main principles are as follows:

(1) the basic pad corrosion resistant materials such as asphalt concrete (100 mm thick);

(2) the foundation pile caps is the Portland cement concrete of sulfate, strength grade of C40, water cement ratio than 0.4, anti-permeability level S8, dosage of cement quartile 340 kg/m ³, the content of chlorine ion in concrete biggest is 0.08%;

(3) foundation pile caps by surface protection use epoxy asphalt coating, frequency 500 μ m thickness, the surface protection foundation beams using epoxy asphalt glass cloth, quartile 1 mm thickness.

(4) reinforced concrete cover depth: basic bottom for 100 mm, basic end face and side of 50 mm;

(5) (6) (7) with pile foundation article anticorrosion measures (4) (5) (6).

6 epilogue

According to the water quality analysis results and geotechnical engineering reports indicated that the underground water and soil based on the corrosion level bearing platform for strong corrosive, the corrosion level of pile foundation for moderately corrosive. The pile foundation mainly through the corrosion of the high performance concrete and reinforced concrete cover depth of increase and blending of corrosion inhibitors and other measures to protective; Foundation pile caps is anticorrosive in addition to the above pile foundation anticorrosion measures outside, still need to pass the corrosion resistant pad and concrete surface daub epoxy asphalt coating (stick epoxy asphalt glass cloth) to protective;

[references]

1. HuangHao shallow buildings such as the concrete structure antisepsis problem [J], the architectural design management, no.4, 2010, 70-71

2. XieBang superior underground engineering (carbon) corrosion of reinforcement in the influence factors of [J] discussion, "western exploration engineering" 10, 2005) 161-162