基于消除氯离子渗入途径的海工钢筋混凝土耐久性实验研究  

Experimental research on coastal reinforced concrete durability based on the elimination of chlorine infiltration channel

作　　者：薛淑萍[1] 伊安海[1] 邵慧[1] 

机构地区：[1]山东水利职业学院,山东日照276826

出　　处：《混凝土》2010年第3期46-47,50,共3页Concrete

摘　　要：氯离子参与的钢筋电化学反应是海工钢筋混凝土耐久性破坏的直接原因,而氯离子是通过混凝土中的孔隙和裂缝,通过长期的物理化学过程进入混凝土内部的,阻断氯离子渗入途径是解决海工混凝土腐蚀问题的有效途径。大量文献显示,处于浪溅区和水位变化区的混凝土,由于干湿交替,其渗入内部的海水浓度较高,容易发生盐析现象,结晶应力与二次钙矾石产生的应力会使混凝土破坏,裂缝增加,氯离子不断向混凝土内部迁移。出于消除氯离子渗入途径的考虑,在循环试验的基础上,通过掺合料替代部分水泥保证混凝土结构密实;通过聚合物水泥浆喷涂堵塞混凝土表面孔隙;通过喷涂微膨胀水泥砂浆得到致密的保护层;通过表层喷洒有机硅形成憎水表面,使盐析和二次钙矾石难以形成,从而保护了既成水泥石,有效地提高了混凝土的耐久性。The electrochemical reaction for steel bars caused by chloride ions is the direct reason for coastal reinforced concrete durability damage.The chloride ions will immerse coastal reinforced concrete by long-term physical and chemical processes when the structure has pores and fractures in the inner of concrete.It is the efficent method for solving coastal concrete erosion problems to prevent the Infiltration Channels of chlo-ride ions.It is showed that salting-out phenomena is easily happened for the coastal concrete which is in the splash and water level variation zones. Owning to alternation of drying and wetting,the concentration of seawater is high in the internal structure of the concrete.So the concrete will be cracked by the crystallization stress and the stresses caused by the secondary ettringite.With increasing of concrete cracks,the chloride ions will continuously migrate the inner of the structures.For the consideration of the elimination of the seepage channel,the following researches have been done in this paper on the basis of the experimental study.The concrete density is ensured by admixtures substituting some cements.The concrete surface voids are blocked by spraying polymer cement slurry.The compact concrete protection layer is obtained by spraying slight expansion cement mortar.The hydrophobic coating is formed by painting silicone in the concrete surface.It is difficult for the salting-out and the secondary et-tringite to form when the above measures are applied.Because the present concrete is protected,the concrete durability is efficiently improved.

关 键 词：海工混凝土 耐久性 渗入途径 氯离子 盐析 

分 类 号：TU528.01[建筑科学—建筑技术科学]