广东省公路工程高性能混凝土关键技术研究

发布时间：2018-06-28 18:34

本文选题：公路工程混凝土 + 石灰石粉　；参考：《北京建筑大学》2014年硕士论文

【摘要】：公路工程混凝土结构的特点是大体积、大表面部位多且暴露于自然环境,其早期抗裂性能是结构耐久性关注的重点。粉煤灰等矿物掺合料在混凝土中的应用越来越广泛,但掺加单一品种矿物掺合料的混凝土,可能存在某些性能不足,不能完全满足工程要求,复合矿物掺合料的应用越来越多。由于石灰石粉是一种新型掺合料,在试验基础上,对石灰石粉复合矿物掺合料混凝土的养护条件及石灰石粉复合矿物掺合料对混凝土强度、早期抗裂性能的影响的相关研究相对很少。本课题“广东省公路工程高性能混凝土关键技术研究”经过广东省实际工程调研,以三种不同养护条件下复合矿物掺合料混凝土的强度、耐久性为研究对象,同时对比不同掺量复合矿物掺合料对混凝土早期抗裂性能的影响。试验结果表明：C30和C50混凝土在标准养护条件下、复合矿物掺合料掺量为20%～50%时,各龄期抗压强度发展满足要求。复合矿物掺合料的组成(质量比)为(石灰石粉+粉煤灰)：矿粉=6：4,石灰石粉：粉煤灰=7：3。对于复合矿物掺合料混凝土,早期不进行湿养护,强度降低幅度很大。掺加复合矿物掺合料不仅经济性较好,还改善了混凝土的早期抗裂性能和耐久性。随着矿物掺合料掺量的增加,混凝土自然碳化深度增加,但养护7天可以将大掺量复合矿物掺合料混凝土28天自然碳化深度控制在3mm以下。混凝土氯离子扩散系数随矿物掺合料掺量的增加而增大,但是总体均在300×10-10cm2/s以内,混凝土渗透性评价为中。
[Abstract]:The characteristics of highway engineering concrete structure are large volume, large surface position and exposed to natural environment. Its early crack resistance is the focus of structural durability. Mineral admixtures such as fly ash are more and more widely used in concrete, but concrete with a single mineral admixture may have some performance deficiencies, which can not fully meet the engineering requirements, and the application of compound mineral admixtures is becoming more and more. Because limestone powder is a new type of admixture, on the basis of experiment, the curing conditions of limestone powder compound mineral admixture concrete and the strength of limestone powder compound mineral admixture to concrete are studied. Relatively few studies have been conducted on the effect of early crack resistance. In this paper, the key technology of high performance concrete in highway engineering in Guangdong province is studied. The strength and durability of concrete with compound mineral admixture under three different curing conditions are studied. At the same time, the effects of different mineral admixtures on the early crack resistance of concrete were compared. The test results show that under the standard curing conditions, the compressive strength development of the concrete at different ages can meet the requirements when the content of the compound mineral admixture is 20 ~ 50. The composition (mass ratio) of compound mineral admixture is (limestone powder fly ash): mineral powder 6: 4, limestone powder: fly ash 7: 3. For composite mineral admixture concrete, the strength decreases greatly without wet curing in the early stage. The addition of compound mineral admixtures not only improves the economy, but also improves the early crack resistance and durability of concrete. The natural carbonation depth of concrete increases with the increase of mineral admixture content, but the natural carbonation depth of concrete with large amount of mineral admixture can be controlled below 3mm in 28 days after curing for 7 days. The chloride diffusion coefficient of concrete increases with the increase of mineral admixture content, but the total content is less than 300 脳 10-10cm2/s, and the concrete permeability evaluation is moderate.
【学位授予单位】：北京建筑大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U414

【参考文献】