原创《早期受冻掺合料混凝土服役性能试验》：本论文为免费优秀的关于掺合料论文范文资料，可用于相关论文写作参考。
摘 要：为评定早期冻融损伤对混凝土结构服役期承载性能及耐久性能的影响规律,通过不同掺合料种类及掺量、不同起冻时刻的混凝土早期受冻试验,对比了不同受冻时刻混凝土服役期的表面损伤形态,研究了起冻时刻、掺合料掺量对早期受冻混凝土服役期抗压强度、劈拉强度、动弹性模量、渗透性的影响规律,探讨了早期受冻对混凝土服役性能的损伤机理.结果表明：起冻时刻对混凝土抗压强度、劈拉强度、动弹模的影响程度均表现为2 h>0.5 h≈8 h>1 d>3 d,劈拉强度损失最明显,动弹模损失次之,抗压强度损失最不显著；掺入20%粉煤灰或15%矿粉或20%煤矸石的混凝土早期受冻后的强度和动弹模损失最小,略小于普通混凝土；随着掺合料掺量的增加,同时刻受冻混凝土试件的抗渗水性和抗渗气性变差；未冻混凝土试件的抗渗性最好,3 d受冻试件次之,1 d受冻试件再次,而0.5、2、8 h受冻试件最差甚至超出AutoClam设备的测试范围.
关键词：掺合料混凝土；早期受冻；服役期；起冻时刻
中图分类号：TU528.01
文献标志码：A 文章编号：1674-4764（2017）05-0093-07
Abstract： In order to evaluate the influence rules of early frost damage on the bearing property and durability of concrete structure in service period, early frost experiments considering different admixtures and different freezing times were carried out. The surface damage forms of different freezing times were compared. The influence rules of freezing times and mineral admixtures on compressive strength, splitting tensile strength, dynamic elastic modulus and permeability of early frost admixture concrete were studied. The damage mechanism of early frost on service performance was discussed. The results showed that the damage degree of freezing time on compressive strength, splitting tensile strength and dynamic elastic modulus embodied as 2 h>0.5 h≈8 h>1 d>3 d. The most obvious loss was the splitting tensile strength, and the next was the dynamic elastic modulus. The least loss was the compressive strength. When 20% fly ash or 15% slag or 20% coal gangue was incorporated into concrete, the strength loss and the dynamic elastic modulus loss was the smallest and smaller than that of common concrete. With the increase of admixture, the anti-water-permeability and anti-air-penetration of concrete specimen at same freezing time were worsen. The anti-permeability of unfrozen concrete was the best, and the next is 3-day frozen concrete. The third is 1-day frozen concrete, and the anti-permeability of 0.5-hour frozen and 2-hour frozen and 8-hour frozen concrete were the worst and even beyond the test range of AutoClam equipment.
Keywords：admixture concrete； early frost； service period； freezing time
秋末冬初、冬末春初季節交替时气候条件多变,气温突变的可能性大为增加,处于施工期的混凝土结构突然受冻情况时有发生,造成混凝土水化过程减缓、内部微裂缝开展等不利影响,此种早期冻伤大多无法修复,对混凝土结构服役期的承载性能和耐久性能造成难以弥补的损害.多年来,混凝土浇筑过程中的受冻、硬化过程中的受冻一直备受关注.文献[1-4]结合现有的混凝土冻融破坏理论,分新浇筑混凝土、硬化过程中混凝土、幼龄期混凝土3个阶段阐述了混凝土早期冻融损伤的破坏机理.文献[5-12]通过混凝土的早期冻融试验研究了早期冻伤混凝土的质量损失、抗压强度损失和孔隙分布变化.然而,目前混凝土早期冻融损伤的研究大多基于《普通混凝土长期性能和耐久性能试验方法标准》（GB/T 50082—2009）进行混凝土材料的早期冻融试验,冻融循环时间短（2～4 h一个循环）,冻融温度固定（-17～-8 ℃）,循环次数多.这种试验环境和实际工程条件存在明显差异,将硬化混凝土冻融试验方法用于研究形态多变、性能时变的早期混凝土冻融损伤规律显然不合理.另外,目前混凝土早期冻融损伤方面的研究较少涉及掺合料,和当前的实际工程不符.模拟实际工程环境研究早期受冻掺合料混凝土的服役期性能,对于准确评定混凝土的早期冻融损伤、早期受冻混凝土结构的承载性能及耐久性能具有重要的理论意义.
掺合料论文参考资料：
结论：早期受冻掺合料混凝土服役性能试验为大学硕士与本科掺合料毕业论文开题报告范文和相关优秀学术职称论文参考文献资料下载，关于免费教你怎么写膨胀水泥方面论文范文。
