抗蚀耐磨混凝土材料研究

发布时间：2018-04-09 19:51

  本文选题：混凝土　切入点：硫酸盐侵蚀　出处：《华北理工大学》2017年硕士论文

【摘要】：硫酸盐侵蚀与高温会造成混凝土的膨胀开裂及强度降低。已有研究表明使用铝酸盐水泥作为胶凝材料的混凝土具有较好的抗硫酸盐侵蚀性能,采用烧结铝矾土、氧化铝陶瓷等耐磨骨料,可配制出高性能高耐磨的混凝土,但是不同掺合料对铝酸盐水泥水化产物在高温下的晶型转变以及对混凝土抗蚀耐磨性的影响尚未清楚。实验中重点研究了铝酸盐水泥体系、土聚水泥体系混凝土高温条件下的抗蚀耐磨性。参照GB/T17671-1999,制备砂浆试块,并将试块分别放置于标准养护室、80℃水中、80℃5%的Na2SO4溶液中养护,以质量损失率、抗压、抗折强度和耐磨度作为评判准则,研究胶凝材料体系、骨料、养护环境对混凝土抗硫酸盐侵蚀与耐磨性的影响。采用X射线衍射(XRD)、扫描电子显微镜(SEM)研究混凝土中硫酸盐侵蚀的反应产物和微观结构。研究结果表明:使用烧铝矾土砂作骨料的铝酸盐水泥混凝土抗折强度、抗压强度、耐磨度都普遍高于使用标准砂的铝酸盐水泥混凝土,掺入三聚磷酸钠后,混凝土的强度和耐磨度都有明显下降;试块的强度越高,耐磨度越高。80℃的高温条件有助于土聚水泥的碱激发反应进行,在80℃水中养护的试块性能显著高于标准养护和80℃硫酸钠溶液中养护的2组。土聚水泥在高温下的抗硫酸盐侵蚀性能良好。通过微观分析,发现三聚磷酸钠对铝酸盐水泥水化的最终产物无明显影响,结合水化热分析与强度测试结果,掺5%的三聚磷酸钠会大量放热,促进铝酸盐水泥早期水化产物CAH_(10)与C_2AH_8转变为C_3AH_6,使混凝土强度降低。骨料中的高铝矿物能有效提高铝酸盐水泥混凝土抗硫酸盐侵蚀性能。
[Abstract]:Sulfate erosion and high temperature will cause expansion cracking and strength reduction of concrete.It has been shown that the concrete with aluminate cement as the cementitious material has better resistance to sulfate erosion, and the high performance and high wear resistant concrete can be prepared by using sintered bauxite, alumina ceramic and other wear-resistant aggregates.However, the effects of different admixtures on the crystalline transformation of aluminate cement hydration products at high temperature and on the corrosion and wear resistance of concrete are not clear.In the experiment, the corrosion and wear resistance of aluminate cement system and soil-aggregate cement system concrete at high temperature were studied.Effect of curing Environment on Sulfate Resistance and Wear Resistance of concrete.The reaction products and microstructure of sulfate erosion in concrete were studied by means of X-ray diffraction and scanning electron microscopy (SEM).The results show that the flexural strength, compressive strength and wear resistance of aluminate cement concrete with bauxite sand as aggregate are generally higher than that of aluminate cement concrete with standard sand.The strength and wear resistance of concrete are obviously decreased, and the higher the strength of the test block, the higher the wear resistance. 80 鈩，

本文编号：1727890