摘要
在混凝土中应用珊瑚废弃物是制备适用于远海岛礁建设所需建筑材料的有效策略,然而过量应用珊瑚废弃物会导致混凝土性能急剧降低。为保证砂浆性能的同时提升珊瑚废弃物的应用率,本文联合应用珊瑚砂(CS)和珊瑚粉(CP)分别取代部分骨料和粘结剂制备砂浆,研究了CS取代率对砂浆的力学性能、自收缩和干燥收缩的影响,并结合微观形貌和孔隙结构分析其影响机制。结果表明:相比于未掺加CS的砂浆,联合应用10wt%~40wt%CS和10wt%CP制备的砂浆具有更高的力学性能。当CS的取代率为30wt%时,砂浆的强度最高,并且其28天抗压强度较基准组提升29.5%。同时,随着CS含量的升高,砂浆的自收缩变形降低。当CS的含量为40wt%时,砂浆的28天自收缩变形与基准组相比降低33.74%。另外,掺加CS也有益于降低砂浆的干燥收缩,当CS的取代率为30wt%时砂浆的干燥收缩值达到最低。CS的多孔结构使其与水泥基体间紧密咬合,并且其内养护作用也促进了界面性能的提升。通过氮吸附测试的孔隙结果也表明掺加30wt%的CS使样品的孔隙率降低,但进一步增加CS的掺量不利于样品的孔隙结构发展。
Application of coral waste in concrete is an effective strategy to produce building materials suitable for offshore island construction,but excessive application of coral waste can lead to drastic degradation of concrete properties.In order to improve the replacement ratio of coral waste while ensuring the performance of mortar,this study combined coral sand(CS)and coral powder(CP)to replace part of the aggregate and binder to produce mortar,and the effect of CS substitution ratio on the mechanical properties,autogenous shrinkage and drying shrinkage of mortar was investigated,and its influencing mechanism was analyzed in combination with microstructure and pore structure.The results demonstrate that the mortar produced by combined application of 10wt%-40wt%CS and 10wt%CP has higher strength than the mortar without CS.When the replacement ratio of CS is 30wt%,the strength of the mortar is the highest,and its 28 days compressive strength is increased by 29.50%compared with the reference group.Meanwhile,with the increase of CS content,the autogenous shrinkage of mortar decreases.When the CS content is 40wt%,the 28 days autogenous shrinkage value of the mortar is decreased by 33.74%,compared with the reference group.In addition,the addition of CS is also beneficial to reduce the drying shrinkage of mortar,and the drying shrinkage of mortar reaches the lowest when the substitution ratio of CS is 30wt%.The porous structure of CS makes it tightly occluded with the cement matrix,and its internal curing effect also promotes the improvement of interface performance.The results of the specific surface area(BET)also show that adding 30wt%CS reduces the porosity of the sample,but further increasing the CS content is not conducive to the development of the pore structure of the sample.
作者
倪雅倩
何智海
石锦炎
贺一烽
刘宝举
NI Yaqian;HE Zhihai;SHI Jinyan;HE Yifeng;LIU Baoju(College of Civil Engineering,Shaoxing University,Shaoxing 312000,China;Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province,Shaoxing 312000,China;Historical and Cultural City Research Center,Shaoxing University,Shaoxing 312000,China;School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-speed Railway Construction Technology,Changsha 410075,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2024年第1期404-413,共10页
Acta Materiae Compositae Sinica
基金
国家自然科学基金项目(51602198)
浙江省自然科学基金(LY20E020006)
中国中铁股份有限公司科技研究开发计划项目(2021-重点-08)。
关键词
珊瑚骨料
砂浆
强度
体积稳定性
微结构
coral aggregate
mortar
strength
volume stability
microstructure
