本文關(guān)鍵詞： 礦山腐蝕環(huán)境 混凝土 結(jié)構(gòu)性能 劣化機(jī)理 腐蝕狀態(tài)評價(jià)　出處：《北京科技大學(xué)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：礦山工程中混凝土結(jié)構(gòu)構(gòu)件的特點(diǎn)是：服役周期長,受力復(fù)雜,同時(shí)還長期遭受復(fù)雜有害環(huán)境的化學(xué)腐蝕。而礦山腐蝕環(huán)境中,地下結(jié)構(gòu)混凝土在應(yīng)力與腐蝕耦合作用下,混凝土材料強(qiáng)度會(huì)逐漸劣化,致使材料局部發(fā)生損傷。當(dāng)損傷累計(jì)到一定程度,混凝土構(gòu)件就會(huì)發(fā)生局部或全部破壞,從而影響結(jié)構(gòu)構(gòu)件在運(yùn)營期間的服役安全性和服役年限,降低結(jié)構(gòu)耐久性。本文以淮北礦業(yè)股份有限公司臨渙煤礦委托項(xiàng)目為依托,針對礦區(qū)地下混凝土結(jié)構(gòu)所處的特殊環(huán)境,在現(xiàn)場調(diào)查的基礎(chǔ)上,采用試驗(yàn)研究、數(shù)值分析、理論分析和數(shù)值模擬方法,重點(diǎn)研究了礦山腐蝕環(huán)境下混凝土構(gòu)件的硫酸鹽侵蝕機(jī)理、強(qiáng)度損傷劣化規(guī)律、斷裂演化規(guī)律、鋼筋與混凝土粘結(jié)退化性能以及腐蝕混凝土在抗壓及斷裂過程中聲發(fā)射信號特征,提出基于聲發(fā)射表征的礦區(qū)混凝土破壞過程的損傷劣化模型。研究內(nèi)容及結(jié)論如下：(1)對實(shí)驗(yàn)室配置的混凝土試樣進(jìn)行了三因素四水平的人工加速硫酸鹽腐蝕試驗(yàn),測試了不同腐蝕時(shí)間下的不同初始損傷、不同養(yǎng)護(hù)齡期和不同硫酸鹽濃度作用下混凝土的抗壓強(qiáng)度,并以抗壓強(qiáng)度為指標(biāo)定義了腐蝕混凝土損傷度,建立了損傷度分別與環(huán)境中硫酸鹽溶液濃度、初始損傷、養(yǎng)護(hù)齡期與應(yīng)力之間的函數(shù)關(guān)系,并給出三因素綜合影響下的損傷度計(jì)算模型。(2)不同初始損傷、不同腐蝕溶液濃度和不同養(yǎng)護(hù)齡期的混凝土在受硫酸鹽溶液侵蝕后抗壓強(qiáng)度總體上表現(xiàn)為先增大后減小的趨勢,而質(zhì)量則是呈現(xiàn)出先降低后增加的趨勢。研究發(fā)現(xiàn)初始損傷越大的混凝土,腐蝕前期抗壓強(qiáng)度增加越快,同樣,腐蝕后期抗壓強(qiáng)度也下降的幅度越大。養(yǎng)護(hù)齡期28天的混凝土在受腐蝕期間,強(qiáng)度一直高于低養(yǎng)護(hù)齡期的混凝土強(qiáng)度。(3)通過三點(diǎn)彎曲梁加速腐蝕試驗(yàn)發(fā)現(xiàn),混凝土斷裂時(shí)刻的峰值荷載受硫酸鹽影響較大。峰值荷載隨腐蝕時(shí)間延長其降低幅度增大,同時(shí)斷裂過程中線彈性段越小,越易進(jìn)入到塑性區(qū),從而加快斷裂進(jìn)程�；炷燎锌诹涸嚰诓煌瑵舛攘蛩猁}溶液浸泡過程中,斷裂韌度整體表現(xiàn)為先增大后降低的趨勢,降低幅度隨硫酸鹽濃度增大而增大。(4)分析了不同腐蝕溶液濃度、不同初始損傷、不同養(yǎng)護(hù)齡期和不同浸泡時(shí)間下腐蝕混凝土抗壓過程中聲發(fā)射信號特征,以及不同腐蝕時(shí)間、不同種類混凝土斷裂過程聲發(fā)射信號特征。用聲發(fā)射活性函數(shù)估計(jì)腐蝕損傷因子,建立腐蝕混凝土損傷劣化方程,定量描述腐蝕混凝土損傷對混凝土力學(xué)性能的影響,發(fā)現(xiàn)有初始損傷的混凝土在受硫酸鹽侵蝕后,腐蝕損傷因子在加載過程中發(fā)展速度快于浸泡前無初始損傷的混凝土(5)鋼筋混凝土試件經(jīng)過720天硫酸鹽侵蝕,變形鋼筋與腐蝕混凝土之間的極限粘結(jié)強(qiáng)度先增加后降低,隨著腐蝕時(shí)間的延長,降低速率在持續(xù)增加。摻入仿鋼纖維的鋼筋混凝土試件在硫酸鹽腐蝕條件下極限粘結(jié)強(qiáng)度高于未摻入仿鋼纖維的鋼筋混凝土試件。(6)利用灰色理論預(yù)測了不同腐蝕因素和不同腐蝕水平下混凝土腐蝕強(qiáng)度。運(yùn)用數(shù)值模擬分析了目前腐蝕混凝土構(gòu)件的受力狀態(tài),評價(jià)了其服役狀況。
[Abstract]:The characteristics of concrete structure in the mine engineering service is: long cycle, complex force, and has long suffered from complex chemical corrosion are harmful to the environment. And mine corrosion environment, underground stress and corrosion in concrete structure under coupling strength of concrete materials will deteriorate gradually, resulting in local material damage. When the cumulative damage to a certain extent, will be concrete in partial or total destruction, thus affecting the structure during operation of service safety and service life, reduce the durability of the structure. In this paper, taking Huaibei mining Limited by Share Ltd commissioned in Linhuan coal mine project, according to the special environment of underground concrete structure mining area, based on the field investigation, the experimental study and numerical analysis, theoretical analysis and numerical simulation, focusing on mining under corrosive environment of concrete sulfate erosion The mechanism of damage and deterioration of strength, fracture evolution, the bond between reinforcement and concrete performance degradation and corrosion of concrete in compression and fracture process characteristics of acoustic emission signals, proposed damage deterioration model of mine concrete damage process based on acoustic emission characterization. Research contents and conclusions are as follows: (1) the accelerated sulphate corrosion test three factors and four levels of laboratory concrete specimens of configuration, different initial damage under different etching time of the test, the compressive strength of the concrete effect of different curing time and different sulfate concentrations, and the definition of corrosion damage of concrete with compressive strength as the index, the damage degree and sulfate concentration in the environment. The initial damage, curing period and function should be the relation between force, calculation model of damage degree three factors and gives the different initial loss (2). Injury, different corrosion solution concentration and different curing period of concrete in sulfate solution after the erosion of the compressive strength of the overall performance of the first increased and then decreased, while the quality is decreased first and then increased. The study found that the greater the initial damage of concrete, corrosion early compressive strength increased more quickly, the same later, the compressive strength of corrosion also decrease more. The curing period of 28 days in concrete due to corrosion during the strength has been higher than the low strength of concrete curing period. (3) through three point bending beam accelerated corrosion test showed that the peak load of concrete mixed fracture time by sulfate influence. The peak load reduce the amplitude increases with prolonging corrosion time, the fracture process of linear elastic section of smaller, more easily into the plastic zone, thus speeding up the process of fracture. The concrete notched beam specimens at different concentrations of sulfuric acid leaching solution Global process, the fracture toughness of the overall performance is first increased and then decreased, with the reduction of sulfate concentration increases. (4) different corrosion solution concentration was analyzed, different initial damage, the AE signal characteristics of corrosion of concrete compressive process of different curing time and different soaking time in different time and different corrosion. Type of fracture process of concrete AE. Estimation of the corrosion damage factor by acoustic emission activity function, establishment of corrosion damage of concrete deterioration equation, the quantitative description of corrosion damage of concrete on concrete mechanical properties, found the initial damage of concrete under sulfate corrosion, corrosion damage factor in the loading process is faster than immersion before the initial damage of concrete (5) reinforced concrete specimens after 720 days of sulphate erosion, deformation limiting viscosity between reinforcement and corrosion of concrete Node strength first increased and then decreased, with the prolongation of corrosion time, reduce the rate continued to increase. The incorporation of steel fiber reinforced concrete imitation specimens under sulfate corrosion under the condition of ultimate bond strength is higher than that of reinforced concrete mixed with steel fiber not imitation specimens. (6) the different corrosion factors and corrosion of concrete under different level the pre corrosion strength by using grey theory. By numerical simulation analyzes the corrosion of concrete stress state, evaluate its service status.

【學(xué)位授予單位】：北京科技大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TD26;TU37

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