废混凝土对GRC耐久性影响研究

发布时间：2018-03-14 17:42

本文选题：废混凝土粉　切入点：废混凝土再生骨料　出处：《北方工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国建筑垃圾的数量已占到城市垃圾总量的80%-90%,但资源化率却不足5%,建筑垃圾中30%-40%为废混凝土,因此,如何有效地处理这些建筑废弃物成为了我们必须面对的课题,也是实现资源再利用的关键。GRC制品具有质轻、抗裂、抗冲击等诸多优点,但是,GRC制品的长期耐久性能降低问题一直限制其在更大范围内应用。因此,为了提高废混凝土的再利用率,同时改善GRC制品的长期耐久性能,本课题将废混凝土应用到GRC中,分析废混凝土对GRC耐久性的影响。本课题主要解决以下问题:①研究以废混凝土再生骨料取代GRC中的天然砂及其与粉煤灰、硅灰复掺对GRC性能的影响。②研究以不同细度废混凝土粉取代GRC中的水泥对GRC性能的影响。③研究以废混凝土粉取代GRC中的水泥及其与粉煤灰、硅灰联合使用对GRC性能的影响。④研究以废混凝土骨料和废混凝土粉同时分别取代GRC中的天然砂和水泥对GRC性能的影响。试验结果表明:①使用废混凝土骨料对GRC性能的改善是有效的,其中以30%废混凝土骨料取代GRC中天然砂的试验组较基准组表现出较好的耐久性。而单掺30%粉煤灰或复掺20%粉煤灰和10%硅灰时,GRC的耐久性较单掺30%废混凝土骨料时还有较大提高。②使用10%的废混凝土粉取代GRC中的水泥并不能达到改善GRC耐久性的效果,而且养护的龄期越长时,GRC中的玻璃纤维受腐蚀越严重,致使GRC的耐久性有所下降,且废混凝土粉越细,玻璃纤维被腐蚀也越严重,耐久性的下降幅度也越大。③当30%废混凝土骨料与10%废混凝土粉复合使用时,GRC的耐久性较单掺10%废混凝土粉时有所提高,但不如单独使用30%废混凝土骨料时效果好。从玻璃纤维被腐蚀的程度也可以看出,单掺10%废混凝土粉的试验组最严重,单掺30%废混凝土骨料的最轻,而二者复掺时,介于二者之间。④当30%废混凝土骨料与30%粉煤灰复掺或与20%粉煤灰和10%硅灰复掺时,GRC的耐久性较基准组和单掺30%废混凝土骨料组有了很大的提高,两者的玻璃纤维被腐蚀情况也较基准组和单掺30%废混凝土骨料组有很大程度的减轻。⑤10%废混凝土粉与30%粉煤灰复掺或与20%粉煤灰和10%硅灰复掺可以有效改善GRC的耐久性,且比单掺10%废混凝土粉效果要好,同时,基体中玻璃纤维被腐蚀程度也明显减轻。⑥单掺30%废混凝土骨料时,GRC基体中CH的结晶程度和玻璃纤维表面被腐蚀程度较基准组有所减轻。当30%废混凝土骨料与30%粉煤灰复掺或与20%粉煤灰和10%硅灰复掺时,GRC基体中CH的结晶程度和玻璃纤维表面被腐蚀程度较单掺30%废混凝土骨料组还要有所减轻。⑦单掺10%废混凝土粉时,GRC基体中CH的结晶程度和玻璃纤维表面被腐蚀程度较基准组有所增强。但当10%废混凝土粉与30%粉煤灰复掺或与20%粉煤灰和10%硅灰复掺时,GRC基体中CH的结晶程度和玻璃纤维表面被腐蚀程度较基准组有所减轻。
[Abstract]:The amount of construction waste in our country has already accounted for 80-90% of the total amount of municipal waste, but the rate of utilization is less than 5%. 30% -40% of construction waste is waste concrete. Therefore, how to deal with these construction wastes effectively has become a subject that we must face. GRC products have many advantages, such as light weight, crack resistance, impact resistance and so on. However, the long-term durability of GRC products can reduce the problem of reducing the long-term durability of GRC products. In order to improve the reuse rate of waste concrete and improve the long-term durability of GRC products, this paper applies waste concrete to GRC. This paper analyzes the influence of waste concrete on the durability of GRC. This subject mainly solves the following problem: 1. Research on replacing natural sand and fly ash in GRC with recycled aggregate of waste concrete. Effect of silica fume admixture on GRC performance. The influence of replacing cement in GRC with waste concrete powder of different fineness on the performance of GRC. 3. Study on replacing cement in GRC with waste concrete Powder and its relation with fly Ash. Effect of silica fume combined use on GRC performance. 4 the effect of replacing natural sand and cement in GRC with waste concrete aggregate and waste concrete powder at the same time on the performance of GRC is studied. The test results show that the use of waste concrete aggregate at 1 / 1 has effect on GRC performance. The improvements that can be made are effective. The test group with 30% waste concrete aggregate instead of natural sand in GRC showed better durability than the reference group, while the test group with only 30% fly ash or 20% fly ash and 10% silica fume had better durability than 30% waste concrete aggregate. The use of waste concrete powder of 10% instead of cement in GRC does not improve the durability of GRC. Moreover, the longer the curing age is, the more serious the corrosion of glass fiber in GRC is, and the finer the waste concrete powder, the more serious the corrosion of glass fiber is. When 30% waste concrete aggregate and 10% waste concrete powder are used together, the durability of GRC is improved compared with that of 10% waste concrete powder. However, it is better to use 30% waste concrete aggregate alone. From the degree of corrosion of glass fiber, it can be seen that the test group with only 10% waste concrete powder is the most serious, and only 30% waste concrete aggregate is the lightest, and when both are mixed together, The durability of 30% waste concrete aggregate mixed with 30% fly ash or 20% fly ash and 10% silica fume is better than that of reference group and 30% waste concrete aggregate group. The corrosion of glass fiber in both groups can also be reduced to a great extent than that of standard group and 30% waste concrete aggregate group. 510% waste concrete powder and 30% fly ash co-admixture or 20% fly ash and 10% silica fume can effectively improve the durability of GRC. And the effect is better than only 10% waste concrete powder, at the same time, The degree of corrosion of glass fiber in matrix was also significantly reduced. 6. 6. The degree of Ch crystallization in matrix and the corrosion degree of glass fiber surface in the matrix were less than those in the reference group. When the aggregate of 30% waste concrete and 30% powder were added, the degree of Ch in the matrix and the corrosion degree of glass fiber in the matrix were also reduced. When coal ash is mixed with 20% fly ash and 10% silica fume, the crystallization degree of Ch and the corrosion degree of glass fiber surface in GRC matrix are more reduced than that in 30% waste concrete aggregate group. 7. 7 and 10% waste concrete powder are added to GRC matrix. The crystallization degree of Ch and the corrosion degree of glass fiber surface were stronger than those of the reference group, but when 10% waste concrete powder was mixed with 30% fly ash or 20% fly ash and 10% silica fume were mixed, the degree of Ch crystallinity and glass fiber in the matrix were increased. The corrosion degree of the surface is less than that of the reference group.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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