再生块状混凝土中ITZs非均质性的纳微表征

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites Pub Date : 2025-04-11 DOI:10.1016/j.cemconcomp.2025.106078

Hanbing Zhao , Yixiang Gan , Fulin Qu , Zhuo Tang , Shuhua Peng , Yangqiao Chen , Wengui Li

{"title":"再生块状混凝土中ITZs非均质性的纳微表征","authors":"Hanbing Zhao , Yixiang Gan , Fulin Qu , Zhuo Tang , Shuhua Peng , Yangqiao Chen , Wengui Li","doi":"10.1016/j.cemconcomp.2025.106078","DOIUrl":null,"url":null,"abstract":"<div><div>Recycled lump concrete (RLC) is a new sustainable construction material for filling large-sized demolished concrete lump (DCL) piles with fresh mortar or concrete. Due to the differences from conventional concrete casting technology, the heterogeneity and cohesion performance of the interfacial transition zones (ITZs) require further investigation. In this study, two types of self-compacting mortar (SCPM) were designed using blends of cement, recycled sand/recycled powder (RS/RP), and fly ash as raw materials. The filling performance of the SCPM was evaluated based on the microstructure, micromechanical properties and phase distribution within the ITZs and the adjacent matrix surrounding DCLs. Both types of SCPM effectively fill the gaps between DCLs, observed in the appearance of specimens. However, the bonding strength of bottom and oblique bottom ITZs of RLC prepared by SCPM without fly ash and superplasticizer was poor, making it impossible to produce ITZ samples from these two locations successfully. The heterogeneity and cohesion strength of the ITZs surrounding the DCLs depends on the distribution of pores and grains. Grains, including RP and fly ash, accumulated at the top and oblique top sides of the DCL due to sedimentation. Fly ash and RP effectively promoted the healing of micro-pores and cracks around DCLs but had a limited effect on pores and cracks with an average equivalent diameter greater than 1 μm. In summary, the ITZs at the top and oblique top sides of the DCLs had a denser microstructure and better bonding performance than those at other locations around the DCLs.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"161 ","pages":"Article 106078"},"PeriodicalIF":10.8000,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Nano- and micro-characterisation on the heterogeneity of ITZs in recycled lump concrete\",\"authors\":\"Hanbing Zhao , Yixiang Gan , Fulin Qu , Zhuo Tang , Shuhua Peng , Yangqiao Chen , Wengui Li\",\"doi\":\"10.1016/j.cemconcomp.2025.106078\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Recycled lump concrete (RLC) is a new sustainable construction material for filling large-sized demolished concrete lump (DCL) piles with fresh mortar or concrete. Due to the differences from conventional concrete casting technology, the heterogeneity and cohesion performance of the interfacial transition zones (ITZs) require further investigation. In this study, two types of self-compacting mortar (SCPM) were designed using blends of cement, recycled sand/recycled powder (RS/RP), and fly ash as raw materials. The filling performance of the SCPM was evaluated based on the microstructure, micromechanical properties and phase distribution within the ITZs and the adjacent matrix surrounding DCLs. Both types of SCPM effectively fill the gaps between DCLs, observed in the appearance of specimens. However, the bonding strength of bottom and oblique bottom ITZs of RLC prepared by SCPM without fly ash and superplasticizer was poor, making it impossible to produce ITZ samples from these two locations successfully. The heterogeneity and cohesion strength of the ITZs surrounding the DCLs depends on the distribution of pores and grains. Grains, including RP and fly ash, accumulated at the top and oblique top sides of the DCL due to sedimentation. Fly ash and RP effectively promoted the healing of micro-pores and cracks around DCLs but had a limited effect on pores and cracks with an average equivalent diameter greater than 1 μm. In summary, the ITZs at the top and oblique top sides of the DCLs had a denser microstructure and better bonding performance than those at other locations around the DCLs.</div></div>\",\"PeriodicalId\":9865,\"journal\":{\"name\":\"Cement & concrete composites\",\"volume\":\"161 \",\"pages\":\"Article 106078\"},\"PeriodicalIF\":10.8000,\"publicationDate\":\"2025-04-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Cement & concrete composites\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S095894652500160X\",\"RegionNum\":1,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CONSTRUCTION & BUILDING TECHNOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cement & concrete composites","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S095894652500160X","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}

引用次数: 0

摘要

再生块状混凝土（RLC）是用新鲜砂浆或混凝土填充大型拆除混凝土块状桩的一种新型可持续建筑材料。由于与传统混凝土浇筑工艺的不同，界面过渡区的非均质性和粘聚性能有待进一步研究。本研究以水泥、再生砂/再生粉（RS/RP）和粉煤灰为原料，设计了两种自密实砂浆（SCPM）。基于微观结构、微观力学性能和相分布，评价了SCPM的填充性能。两种类型的SCPM有效地填补了dcl之间的空白，在标本的外观上观察到。但是，不加粉煤灰和高效减水剂的SCPM制备的RLC的底部和斜底ITZ结合强度较差，无法在这两个位置成功制备ITZ样品。在dcl周围的itcs的非均质性和内聚强度取决于孔隙和晶粒的分布。由于沉降作用，颗粒（包括RP和粉煤灰）在DCL顶部和斜顶侧堆积。粉煤灰和RP能有效促进dcl周围微孔和裂纹的愈合，但对平均等效直径大于1 μm的微孔和裂纹影响有限。综上所述，与dcl周围其他位置相比，dcl顶部和斜顶侧的itcs具有更致密的微观结构和更好的键合性能。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

查看原文本刊更多论文

Nano- and micro-characterisation on the heterogeneity of ITZs in recycled lump concrete

Recycled lump concrete (RLC) is a new sustainable construction material for filling large-sized demolished concrete lump (DCL) piles with fresh mortar or concrete. Due to the differences from conventional concrete casting technology, the heterogeneity and cohesion performance of the interfacial transition zones (ITZs) require further investigation. In this study, two types of self-compacting mortar (SCPM) were designed using blends of cement, recycled sand/recycled powder (RS/RP), and fly ash as raw materials. The filling performance of the SCPM was evaluated based on the microstructure, micromechanical properties and phase distribution within the ITZs and the adjacent matrix surrounding DCLs. Both types of SCPM effectively fill the gaps between DCLs, observed in the appearance of specimens. However, the bonding strength of bottom and oblique bottom ITZs of RLC prepared by SCPM without fly ash and superplasticizer was poor, making it impossible to produce ITZ samples from these two locations successfully. The heterogeneity and cohesion strength of the ITZs surrounding the DCLs depends on the distribution of pores and grains. Grains, including RP and fly ash, accumulated at the top and oblique top sides of the DCL due to sedimentation. Fly ash and RP effectively promoted the healing of micro-pores and cracks around DCLs but had a limited effect on pores and cracks with an average equivalent diameter greater than 1 μm. In summary, the ITZs at the top and oblique top sides of the DCLs had a denser microstructure and better bonding performance than those at other locations around the DCLs.

求助全文

通过发布文献求助，成功后即可免费获取论文全文。去求助

来源期刊

Cement & concrete composites 工程技术-材料科学：复合

CiteScore

18.70

自引率

11.40%

发文量

459

审稿时长

65 days

期刊介绍： Cement & concrete composites focuses on advancements in cement-concrete composite technology and the production, use, and performance of cement-based construction materials. It covers a wide range of materials, including fiber-reinforced composites, polymer composites, ferrocement, and those incorporating special aggregates or waste materials. Major themes include microstructure, material properties, testing, durability, mechanics, modeling, design, fabrication, and practical applications. The journal welcomes papers on structural behavior, field studies, repair and maintenance, serviceability, and sustainability. It aims to enhance understanding, provide a platform for unconventional materials, promote low-cost energy-saving materials, and bridge the gap between materials science, engineering, and construction. Special issues on emerging topics are also published to encourage collaboration between materials scientists, engineers, designers, and fabricators.