基于低碳地聚物的长江下游疏浚砂固化块体力学性能和干缩特性试验研究  

Experimental study on mechanical properties and drying shrinkage characteristics of dredged sand blocks in lower reaches of the Yangtze River based on low-carbon geopolymers

作　　者：冯明 江朝华[1] 孙建伟 谢兆飞 FENG Ming;JIANG Chao-hua;SUN Jian-wei;XIE Zhao-fei(College of Harbour,Coastal and Offshore Engineering,Hohai University,Nanjing 210098,China;Zhaocun Reservoir Management Office of Jiangning District,Nanjing 211155,China;Water Conservancy Bureau of Guanyun County,Lianyungang 222299,China)

机构地区：[1]河海大学港口海岸与近海工程学院,江苏南京210098 [2]南京市江宁区赵村水库管理所,江苏南京211155 [3]江苏省灌云县水利局,江苏连云港222299

出　　处：《水运工程》2023年第1期18-23,共6页Port & Waterway Engineering

基　　金：国家重点研发计划项目(2021YFB2600200);广西重点研发计划项目(2021AB22114)。

摘　　要：长江下游疏浚砂主要为超细砂(细度模数0.1~0.5),粒径小、颗粒级配不均,工程利用困难。以长江下游疏浚砂为主要原料,用碱活化低碳地聚物替代普通水泥制备人工块体,开展力学性能和干缩特性试验研究。采用短切纤维解决碱活化体系造成的易收缩开裂问题。试验结果表明:1)在激发剂Na_(2)O掺量为5%、模数为1.0时,块体28 d抗压和劈裂抗拉强度分别为48.20、6.43 MPa,后期强度不倒缩。2)玄武岩和聚丙烯纤维均能明显抑制块体的线性干缩。玄武岩纤维增强力学性能的能力强于聚丙烯纤维,能够使块体微观结构更致密、整体性更强。The dredged sand in the lower reaches of the Yangtze River is mainly ultra-fine sand(with a fineness modulus of 0.1-0.5),with small particle size and uneven particle gradation,which can be hardly used in engineering.With dredged sand in the lower reaches of the Yangtze River as the main raw material,we replace ordinary cement with alkali-activated low-carbon geopolymers to prepare artificial blocks and test their mechanical properties and drying shrinkage characteristics.Moreover,we use chopped fibers to solve the problem of easy shrinkage and cracking caused by the alkali activation system.The test results show that:1)When the content of the activator Na_(2)O is 5%,and the modulus is 1.0,the compressive strength and splitting tensile strength of the blocks after 28 days are 48.20 and 6.43 MPa,respectively,and the strength does not shrink in the later period.2)Both basalt and polypropylene fibers can significantly inhibit the linear drying shrinkage of the blocks.Basalt fibers have stronger mechanical properties than polypropylene fibers,which can make the microstructure of blocks more compact and more integrated.

关 键 词：疏浚砂 地聚物 干燥收缩 

分 类 号：U614[交通运输工程—船舶及航道工程]