通过优化预处理方法提高回收聚合混凝土的性能:微结构视角
Maja Kępniak1, Filip Chyliński2, Piotr Woyciechowski3
1Faculty of Civil Engineering, Warsaw University of Technology, Al. Armii Ludowej 16, 00- 637, Warsaw, Poland. maja.kepniak@pw.edu.pl.
Scientific reports
|August 16, 2025
概括
回收混凝土聚合物 (RCA) 的预处理提高了混凝土的可持续性. 树脂处理减少了碳化,而水浸泡增强了界面过渡区 (ITZ),尽管树脂聚合物降低了强度.
科学领域:
- 材料科学 材料科学 材料科学
- 土木工程 土木工程是指土木工程.
- 可持续建筑 可持续建筑
背景情况:
- 回收混凝土聚合物 (RCA) 在建筑领域提供了一个可持续的替代品,解决了废物管理的挑战.
- 在RCA混凝土中,旧和新水泥矩阵之间的接口过渡区 (ITZ) 是一个关键的限制.
- 需要有效的预处理方法来提高RCA在新的混凝土应用中的性能.
研究的目的:
- 评估RCA的工业可行的预处理方法:洗,浸水和树脂浸.
- 评估这些预处理对混凝土微观结构性质和耐久性的影响.
- 根据ITZ特性和耐久性要求建立一个选择RCA预处理的框架.
主要方法:
- 对ITZ进行半定量微结构分析.
- 耐久性测试,包括碳化深度测量.
- 混凝土样品的压力和屈曲强度测试.
- 在ITZ的度分析.
主要成果:
- 树脂处理通过孔隙结构的修改使碳化深度降低了38%.
- 浸泡在水中可以通过优化水合期间释放的水分来提高ITZ密度.
- 树脂处理的聚合物由于粘合性差,导致压力强度较低.
- 和再生聚合混凝土的强度与天然聚合混凝土相比,强度相似,但碳化深度略高.
- 和树脂预处理在影响ITZ密度方面最有效,以度为指标.
结论:
- 预处理方法显著影响ITZ特性和使用RCA制成的混凝土的耐用性.
- 水浸浸和树脂浸对ITZ增强和碳化抵抗提供了明显的好处.
- 建立了选择RCA预处理方法的实际框架,平衡性能和可持续性目标.
相关概念视频
Deleterious Substances in Aggregate
250
Deleterious substances in aggregates can be detrimental to the quality and durability of concrete. These substances include organic impurities like loam, which interfere with cement hydration and are usually present in the sand. These prevent a good bond between aggregate and cement paste. Organic impurities can be detected using the colorimetric test, where the darkness of a solution after agitation indicates the level of organic content.
Another type of impurity is clay and fine material that...
Another type of impurity is clay and fine material that...
250
Microcracking in Concrete
208
Microcracking in concrete refers to the tiny cracks that can form within the material even before any external load is applied. These microcracks typically occur at the interface between the coarse aggregate and the hydrated cement paste, often as a result of differential volume changes prompted by variations in stress-strain behavior, as well as thermal and moisture movement. Initially, these microcracks remain stable and do not grow substantially until the concrete is stressed to about 30...
208
Preplaced Aggregate Concrete
137
Preplaced aggregate concrete is ideal for construction environments that are not easily accessible. The process begins by properly wetting the gap-graded coarse aggregates to remove the dirt, then placing it in the form and compacting it. Voids are filled with a mortar mix pumped under pressure through slotted pipes. This mortar typically consists of Portland cement, pozzolan, fine aggregates, water, and a fluidizing aid. The pozzolan helps reduce bleeding and segregation while improving the...
137
Design Example: Managing Concrete Workability
121
This example deals with managing the workability of concrete for a raft foundation project under hot weather conditions. Workability is crucial for ensuring the concrete is easy to place, compact, and finish. In this scenario, a slump test — a common method to measure the workability of fresh concrete — initially indicated low workability. This was attributed to the rapid water loss from the concrete mix, exacerbated by the high temperatures causing the course aggregates to heat up.
121
Frost Resistant Concrete
135
Concrete's susceptibility to frost damage during freeze-thaw cycles demands strategic measures to enhance its frost resistance. Employing techniques like air entrainment, adjusting the water-cement ratio, proper curing, and selecting appropriate aggregates are essential.
Introducing microscopic air bubbles into the concrete mix through air entrainment creates small voids that accommodate ice expansion, thereby reducing internal pressures and preventing cracking. The optimal amount of...
Introducing microscopic air bubbles into the concrete mix through air entrainment creates small voids that accommodate ice expansion, thereby reducing internal pressures and preventing cracking. The optimal amount of...
135
Bonding and Strength of Aggregate
259
The bond between aggregate particles and the cement matrix is significantly influenced by the shape and surface texture of the aggregates. High-strength concretes benefit from a rougher texture, which leads to stronger bonding due to greater adhesion. Angular aggregates with larger surface areas also enhance this bond. The bonding quality, however, is complex to assess as no universally accepted test exists. Good bonding is indicated when a crushed concrete specimen shows some aggregate...
259


