基于二氧化碳泡沫水泥浆的淤泥固化研究  

Sludge solidification based on carbon dioxide foam cement slurry

作　　者：丰土根[1] 厉治平 张箭 谢康 FENG Tugen;LI Zhiping;ZHANG Jian;XIE Kang(Key Laboratory of Ministry of Education for Geotechnical Engineering,Hohai University,Nanjing 210098,China;CCCC National Engineering Research Center of Dredging Technology and Equipment Co.,Ltd.,Shanghai 200092,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]中交疏浚技术装备国家工程研究中心有限公司,上海200092

出　　处：《岩土工程学报》2024年第12期2538-2547,共10页Chinese Journal of Geotechnical Engineering

摘　　要：河湖疏浚会产生大量疏浚淤泥,其含水率、压缩性均较高。采用二氧化碳作为泡沫气体源制备二氧化碳泡沫水泥浆材料并以此作为固化材料开展淤泥改良,对疏浚淤泥的资源再利用及对实现碳中和目标具有重要的意义。基于传统空气泡沫水泥浆制备技术与普通水泥基固碳机理,采用二氧化碳替代空气制备二氧化碳泡沫水泥浆并以此进行淤泥固化,对泡沫浆液养护后形成结石体试块的力学性能以及疏浚淤泥固化后形成填料的力学性能和微观结构进行了试验研究。研究结果表明:发泡剂A_(2)和稳泡剂C_(1)的最佳组合为4,5 g/L;水泥水化水解产物中Ca(OH)_(2)与CO_(2)生成CaCO_(3)的转化率约增加26.1;水泥浆中粉煤灰的最佳掺量为30%;固化后形成的固化料的无侧限抗压强度、内摩擦角及黏聚力与泡沫浆液的掺量呈近似线性递增关系,而渗透系数与泡沫浆液的掺量呈近似线性递减关系。研究成果为淤泥固化的工程应用和二氧化碳“变废为宝”的途径提供重要指导。River and lake dredging will produce a large amount of dredged sludge with high water content and compressibility.Using the carbon dioxide as the foam gas source to prepare carbon dioxide foam cement slurry and use it as the solidification material to carry out sludge improvement is of great significance to the reuse of dredged sludge resources and to achieve the goal of carbon neutrality.Based on the traditional air foam cement slurry preparation technology and ordinary cement-based carbon fixation mechanism,the carbon dioxide foam cement slurry is prepared with carbon dioxide instead of air,which is used to solidify the sludge.The mechanical properties of stone test blocks formed after the curing of foam slurry and the mechanical properties and microstructure of filler formed after the solidification of dredged sludge are studied experimentally.The results show that the best combination of foaming agent and foam stabilizer is A24g/L,C15g/L.The conversion rate of Ca(OH)_(2)and CO_(2)to CaCO_(3)in the cement hydration hydrolysis product increases by about 26.1%.The optimal content of fly ash in cement slurry is 30%.The unconfined compressive strength,internal friction angle and cohesion of the solidified materials formed after curing approximately linearly increase with the content of foam slurry,while the permeability coefficient approximately linearly decreases with the content of foam slurry.The research results provide important guidance for the engineering application of sludge solidification and the way to"turn waste into treasure"of carbon dioxide.

关 键 词：疏浚淤泥 二氧化碳 泡沫水泥浆 淤泥固化 力学性能 

分 类 号：TU43[建筑科学—岩土工程]