【作者】 张航；

【导师】 杨长辉；

【作者基本信息】 重庆大学 ， 材料科学与工程， 2010， 硕士

【摘要】 近年来,海水海砂建材资源化趋势越来越明显,但海水海砂中的氯化物以及硫酸盐等会加快混凝土中钢筋锈蚀,对混凝土耐久性有负面影响,制约了海水海砂在混凝土中的应用。为了延长海水海砂混凝土结构的使用寿命,通过采用高效阻锈剂、多种技术措施协同作用降低海水海砂混凝土中的钢筋锈蚀速率是重要途径之一。目前,复合型阻锈剂已成为国外阻锈剂领域的研究热点,它具有高效、可靠、环保等优点,但国内研究多数是关于已有阻锈剂的性能测试分析,对阻锈剂的复配及作用机理的研究不多。加强复合阻锈剂组成优化和作用机理的研究对延长海水海砂混凝土结构的使用寿命具有重要意义。本文重点研究了单组份阻锈剂和复合型阻锈剂、养护条件、矿物掺合料、成型工艺对海水海砂砂浆和/或混凝土中钢筋锈蚀的影响,采用X射线衍射(XRD)、透射扫描电镜(TSEM)、X射线能谱分析(XEDS)、傅立叶变换拉曼光谱(FT-Raman)等方法分析水泥水化产物相组成、钢筋与混凝土交界面微观结构与组成、有机分子在钢筋表面吸附等,研究阻锈剂的作用机理。研究表明:①单组份阻锈剂掺入海水海砂砂浆中,延缓了氯离子对钢筋的破坏作用,提高了钢筋钝化膜的稳定性,以自然海水作为浸泡液,经过30次浸烘循环后,钢筋锈积率和失重率明显减小,根据极化电位和钢筋锈蚀率判断试验的几种单组份阻锈剂缓蚀效果由强到弱排列为三乙醇胺(TEA)≈氨甲基丙醇(AMP)>单氟磷酸钠(MFP)>硝酸锂(LiNO3)≈氢氧化锂(LiOH)>二甲基乙醇胺(DMEA)>三乙氧基硅烷(TES)。②复合型阻锈剂掺入海水海砂砂浆和/或混凝土中,可以显著降低钢筋的锈积率和失重率,提高砂浆或混凝土抵抗氯离子侵蚀的能力,分别以自然海水、3.5%的NaCl溶液、6.0%的NaCl溶液作为浸泡液,经过100次浸烘循环后,钢筋锈蚀率上升幅度很小,保持了稳定的缓蚀效果。A3阻锈剂的适宜掺量为1.4%～1.7%,A1阻锈剂的缓蚀效果与泰诺Mucis ad 19L/D阻锈剂相当。③在海水海砂混凝土浸烘循环中,相比于3.5%和6.0%的NaCl溶液作为浸泡液,以自然海水作为浸泡液导致钢筋锈蚀率明显增加;偏高岭土和复合型阻锈剂同时掺入时,可以产生协同效应,缓蚀效果显著增强,偏高岭土掺量小于20%时,缓蚀效果随掺量增加而增强;在钢筋表面裹浆,并在裹浆层中掺入A3阻锈剂,缓蚀效果增强,裹浆层厚度小于7.5mm时,缓蚀效果随厚度增加而增强。④阻锈剂A2掺入海水海砂砂浆中降低了砂浆的流动度和强度,阻锈剂A1和A3增加了砂浆的流动度,对砂浆强度无不利影响;阻锈剂A3掺入海水海砂混凝土中延缓了水泥的水化作用,主要抑制了C-S-H凝胶早期的形成和发展,增强了后期混凝土结构的密实性;阻锈剂A3可以通过有机物的吸附及密封分散作用、无机盐的化学反应沉淀作用等吸附在钢筋与混凝土交界面处,增强钢筋钝化膜的稳定性。⑤醇胺化合物、表面活性剂、磷酸盐和硝酸盐这四种物质基于各自的阻锈机理,按照一定比例组成复合型阻锈剂时,可以产生较好的协同缓蚀作用,阻锈性能优于Mucis ad 19L/D泰诺迁移性阻锈剂,其适宜掺量为胶凝材料的1.4~1.7%。更多还原

【Abstract】 In recent years, the current of seawater and sea sand be used as building materials is obvious, but chloride and sulphate included in them will accelerate corrosion rate of rebar in concrete, they have an adverse effect on durability of concrete, so, the application of seawater and sea sand in concrete be restricted.For prolonging the useful life for structure of concrete based on seawater and sea sands, reducing corrosion rate of rebar in concrete based on seawater and sea sands by using highly active corrosion inhibitor and synergistic reaction of different technical measures is one of important ways. At present, composite corrosion inhibitor has become a hot in field of corrosion inhibitor overseas, it has many advantages,such as highly active、reliable、environmental protection and so on, whereas, domestic scholar research on test analysis of corrosion inhibitor’s performance mainly, seldom study about compositional formulation and action mechanism of corrosion inhibitor, so, strengthening research about compositional formulation and mechanism of corrosion inhibitor have significance for prolonging the useful life for structure of concrete based on seawater and sea sands.The effects of corrosion inhibitors (Composite corrosion inhibitor A1、A2、A3and Mucis ad 19L/D)、curing conditions、mineral admixture、moulding process on rebar corrosion in mortar and/or concrete based on seawater and sea sands were studied in this paper. Phase composition of cement hydratation product、microstructure and composition of the interface between rebar and concrete、polar molecule adsorbed in rebar surface were analyzed by way of X-ray diffraction(XRD)、Transmission scanning electron microscopy (TSEM)、X-ray energy dispersive spectroscopy (XEDS)、Fourier transform Raman spectrum(FT-Raman), discussed action mechanism of corrosion inhibitor. Research shows:①Acceding single composition corrosion inhibitor to mortar based on seawater and sea sands can delay the damaging effects of Cl- on rebar, and improve the stability of rebar passive film, rusty accumulation rate and weight loss of rebar for samples soaked in seawater decreased obviously after 30 times soak-warm circulation, according to slope shifted to negative direction of polarization potential of rebar and corrosion rate of rebar, estimating several trial single composition corrosion inhibitors’corrosion inhibition ranked from strong to weak for TEA≈AMP>MFP>LiNO3≈LiOH>DMEA>TES. ②Acceding composite corrosion inhibitor to mortar and/or concrete based on seawater and sea sands can observably reduce rusty accumulation rate and weight loss of rebar, improve ability to resist chloride ion penetration of mortar and/or concrete, corrosion rate of rebar for samples soaked in seawater、3.5%NaCl solution、6.0%NaCl solution respectively increased weakly after 100 times soak-warm circulation, and remain stable corrosion inhibition over an extended period. Corrosion inhibition is best when acceding 1.4%～1.7% A3 corrosion inhibitor to mortar and/or concrete, A1 and Mucis ad 19L/D’corrosion inhibition is nearly.③With regard to concrete based on seawater and sea sands, samples soaked in seawater lead rusty accumulation rate and weight loss of rebar increased dramatically, comparing with samples soaked in NaCl solution; Synergistic effect can be produced when acceding metakaolin and composite corrosion inhibitor at the same time, and corrosion inhibition enhanced obviously, corrosion inhibition was enhanced with the increase content when metakaolin content is less than 20%; Corrosion inhibition was enhanced when rebar being wrapped cement paste, and acceding A3 into cement paste, corrosion inhibition was enhanced with the increase thickness when cement paste thickness is less than 7.5mm.④Acceding corrosion inhibitor A2 to mortar based on seawater and sea sands reduced mobility and intensity of mortar, corrosion inhibitor A1 and A3 increased mobility, without negative influence on strength of mortar; Corrosion inhibitor A3 delayed hydration of cement, mainly restrained forming and developing of C-S-H gel early, but enhanced compactibility of concrete structure later period; Corrosion inhibitor A3 can adsorb on interface between rebar and concrete by function of adsorption、airproofed、decentralization、chemical reaction deposition of inorganic salt and so on, thus it also improved stability of rebar passive film.⑤It can produce good cooperativity corrosion inhibition when corrosion inhibitor being made up of alcohol amine compound、surfactant、phosphate、nitrate based on different mechanism of corrosion inhibition, further more, it have a better corrosion inhibition than Mucis ad 19L/D, the proper poraver of it is 1.4~1.7wt.% for cementing material.更多还原