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1.
本通过将混凝土结构用钢筋放置于腐蚀介质(PH=4~5弱酸性溶液)环境中,对不同腐蚀程度的钢筋进行强度和伸长率等力学性能试验,并将试验结果与未经腐蚀的钢筋对比,探讨腐蚀对钢筋力学性能的影响。  相似文献   

2.
对瑞安市教座典型的混凝土结构构筑物的腐蚀破坏状况进行了调查分析.结果表明,飞云江沿岸混凝土结构腐蚀比较严重,许多构筑物的混凝土保护层过薄,有的出现了内部钢筋锈蚀、混凝土顺筋开裂和剥落等现象.主要原因有结构设计不合理、施工质量差、化学侵蚀等.  相似文献   

3.
混凝土中钢筋腐蚀过程的研究现状及评述   总被引:2,自引:0,他引:2  
阐述了混凝土中钢筋腐蚀过程的研究背景,从混凝土碳化,氯离子侵蚀,钢筋锈蚀过程等方面总结归纳了国内外混凝土中钢筋腐蚀过程的研究成果,并提出了目前混凝土中钢筋腐蚀过程研究急需解决的问题。  相似文献   

4.
不锈钢钢筋在混凝土结构中的应用   总被引:1,自引:0,他引:1  
在侵蚀性或暴露性环境中,钢筋腐蚀成为引起钢筋混凝土结构破坏的主要因素,在众多的防腐措施中,不锈钢钢筋对混凝土建筑物的长寿命和维修简单化做出了贡献。  相似文献   

5.
腐蚀是影响混凝土结构酎久性、可靠性的至关重要的因素.为了保证防腐蚀工程的质量,在设计中应根据腐蚀介质的性质、浓度和作用条件,结合工程部位的重要性等因素,正确选择防腐蚀材料和构造;在施工中应严格执行科学的制度,精心施工,确保建筑工程质量,提高建筑物使用寿命.  相似文献   

6.
研究目的:预测保护层开裂的时间以及分析锈胀参数 研究方法:基于混凝十的各向异性损伤,建立考虑钢筋腐蚀产物混凝十三者不同力学性能的钢筋锈胀导致保护层开裂的数学模型。模型考虑了腐蚀产物对钢筋混凝土界面区的孔隙和混凝十开裂裂缝的填充效应,采用了非线性分析算法,预测了开裂过程中每一时刻混凝土构件的应变与位移场以及混凝土保护层开裂时间,最后将模型预测值与试验值进行对比。 1.当混凝土出现裂缝之后,随着腐蚀产物对裂缝的填充,混凝土的环向拉应变的增长速率减缓;2.选定钢筋的型号、直径以及混凝土的强度之后,可通过增大保护层的厚度来减小钢筋锈胀开裂的风险。  相似文献   

7.
由于各种原因致使钢筋表面的钝化膜受到破坏,成为活化态时,钢筋就容易腐蚀.本文分析了受腐蚀钢筋混凝土结构性能的研究现状.通过对其腐蚀机理的研究,提出了钢筋混凝土在受腐蚀的情况下,结构的抗弯性能、抗剪性能以及在使用荷载作用下的结构性能分析.  相似文献   

8.
灌浆料加速腐蚀仪的研制与应用   总被引:1,自引:0,他引:1  
参照钢筋阳极极化作用原理和加速腐蚀实验方法,研制了具有6套能同时独立工作的腐蚀装置的灌浆料加速腐蚀仪。试验方法是在恒电位条件下测定腐蚀电流急剧变化时所经历的时间,并由此反映灌浆料在极端苛刻的腐蚀条件下抵御氯离子侵蚀的能力。应用该仪器对预应力混凝土灌浆料的优选进行了系统试验,取得了良好的效果。结果表明该加速腐蚀仪具有良好的可靠性和精度,可用于灌浆料的抗氯离子侵蚀性能的试验研究。  相似文献   

9.
混凝土结构是我国建筑工程及桥梁工程中的主要结构形式。目前我国混凝土结构用钢筋年消费量2500万t左右,预应力筋年消费量35万t左右。为提高混凝土结构施工质量及促进建筑用钢技术进步,应大力研究钢筋工程及预应力工程施工技术。  相似文献   

10.
混凝土结构用钢的腐蚀应从钢材的生产质量、施工质量和外界环境三方面分别采取措施加以控制.而钢结构用钢应重点处理好与周围环境的关系,并应根据所处环境选取最经济有效的防腐措施.  相似文献   

11.
针对混凝土结构中钢筋的锈蚀问题,总结了锈蚀钢筋力学性能的研究方法、锈蚀对钢筋力学性能的影响及锈蚀钢筋力学性能的变化规律等研究现状,提出了有待继续研究的问题,为进一步建立锈蚀钢筋模型和加强锈蚀钢筋防护奠定基础.  相似文献   

12.
Corrosion of steel rebar is the most important durability problem of reinforced concrete. The aim of this research was to investigate the corrosion behavior of steel rebar in simulated pore solutions and gangue-blended cement mortar. The simulated pore solutions were based on the pore solution composition ofgangue-blended cement. The pH and CI concentration of simulated pore solutions had significant effects on corrosion potential. However, an increase in pH reduced the influence of Cl- concentration on corrosion potential. The corrosion behavior of steel rebar in gangue-blended cement is different from that in simulated solutions. The gangue cementitious mortar surrounding steel rebar provides stable passivity environments for steel, leading to a decrease in ion diffusion coefficients. Alternating current impedance (ACI) analysis results indicated that the indicator Rc for concrete resistivity is higher for gangue mortar than for ordinary Portland cement (OPC), which improves its corrosion potential. The results from energy dispersive X-ray analysis (EDX) showed more aluminates and silicates at the rebar interface for gangue-blended cement. These aluminates improve the chloride binding capacity of hydrates in mortar, and increase the corrosion protection of steel rebar.  相似文献   

13.
INTRODUCTION Steel rebar embedded in concrete is protectedagainst corrosion by the thin passive film on its sur-face and the physical protection from concrete. Thealkaline environment (pH≥12.5) of the concrete poresolution triggers passivation on the rebar surface andformation of the protective oxide film. The physicaprotection of concrete coverage hinders the invasionof aggressive agents. However, this passivity can bebroken down by local pH loss as a result of concretecracking or the…  相似文献   

14.
玄武岩纤维具有优异的耐腐蚀性能,采用玄武岩纤维材料(BFRP)筋代替钢筋是一种解决钢筋锈蚀问题的潜在方法。通过6根试验梁,研究不同剪跨比下BFRP筋混凝土粱的抗剪性能。试验表明,BFRP筋混凝土梁呈脆性破坏,破坏位置集中在分配梁加载点附近;随着剪跨比的减小,斜截面初裂荷载逐渐提高,且逐渐接近于极限荷载;混凝土梁开裂前,挠度增长缓慢,开裂后增长较快,表现为荷载-挠度曲线呈折现变化。  相似文献   

15.
In this study, two full-size concrete walls were tested and analyzed to demonstrate the effectiveness of a chemically reactive enamel (CRE) coating in improving their mechanical behavior under blast loading: one with CRE-coated rebar and the other with uncoated rebar. Each wall was subjected in sequence to four explosive loads with equivalent 2, 4, 6-trinitrotoluene (TNT) charge weights of 1.82, 4.54, 13.6, and 20.4 kg. A finite element model of each wall under a close-in blast load was developed and validated with pressure and strain measurements, and used to predict rebar stresses and concrete surface strain distributions of the wall. The test results and visual inspections consistently indicated that, compared with the barrier wall with uncoated reinforcement, the wall with CRE-coated rebar has fewer concrete cracks on the front and back faces, more effective stress transfers from concrete to steel rebar, and stronger connections with its concrete base. The concrete surface strain distributions predicted by the model under various loading conditions are in good agreement with the crack patterns observed during the tests.  相似文献   

16.
Bond strength improvement of GFRP rebars with different rib geometries   总被引:1,自引:0,他引:1  
Based on the Canadian Standards Association (CSA) criteria,105 pullout specimens were tested to investigate the effect of different rib geometries on bond strength of glass fiber reinforced polymer (GFRP) rebars embedded in concrete. Two kinds of conventional reinforcing rebars were also studied for comparison. Each rebar was embedded in a 150 mm concrete cube,with the embedded length being four times the rebar diameter. The experimental parameters were the rebar type,rebar component,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Theoretical analysis was also carried out to explain the experimental phenomena and results. The experimental and theoretical results indicated that the bond strength of GFRP rebars was about 13%~35% lower than that of steel rebars. The bond strength and bond-slip behavior of the specially machined rebars varied with the rebar type,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Using the results,design recom-mendations were made concerning optimum rib geometries of GFRP ribbed rebars with superior bond-slip characteristics,which concluded that the optimal rib spacing of ribbed rebars is the same as the rebar diameter,and that the optimal rib height is 6% of the rebar diameter.  相似文献   

17.
依据有关的试验结果,探讨了钢筋砼结构中砼表面裂缝和钢筋处裂缝宽度及钢筋锈蚀三者之间的关系,并分析了钢筋产生锈蚀的原因,认为以砼表面裂缝宽度作为钢筋锈蚀的度量标准不尽合理,控制钢筋处裂缝宽度防止钢筋的局部锈蚀较为有效  相似文献   

18.
针对现有净水厂或污水处理厂钢筋混凝土水池池壁角隅处配筋方式存在的问题,利用MIDAS GEN软件对池壁进行有限元分析,在满足池壁角隅处的受力要求和构造要求前提下,在现有的常规钢筋配置方式基础上对池壁角隅处配筋方式进行优化。与原配筋方式相比,优化后的配筋方式节省了钢筋用量、减少了施工工序、降低了工程成本。  相似文献   

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