膨胀珍珠岩调控固化淤泥物理-力学性能的方法  

Method of using expanded perlite to regulate physico-mechanical properties of solidified sludge

作　　者：韩爽 谈云志[1] 杨舒涵 明华军[1,3] 吴军[1,3] 王冲 肖宇 HAN Shuang;TAN Yun-zhi;YANG Shu-han;MING Hua-jun;WU Jun;WANG Chong;XIAO Yu(Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang,Hubei 443002,China;Changjiang Institute of Survey Planning Design and Research,Wuhan,Hubei 430010,China;Yichang Key Laboratory of the Resources Utilization for Problematic Soils,China Three Georges University,Yichang,Hubei 443002,China)

机构地区：[1]三峡大学防灾减灾湖北省重点实验室,湖北宜昌443002 [2]长江勘测规划设计研究有限责任公司,湖北武汉430010 [3]三峡大学特殊土资源化利用宜昌市重点实验室,湖北宜昌443002

出　　处：《岩土力学》2024年第11期3324-3332,共9页Rock and Soil Mechanics

基　　金：国家大坝安全工程技术研究中心开放基金(No.CX2023B07);国家自然科学基金(No.52209136)。

摘　　要：疏浚淤泥含水率高导致干化和固化成本过高。充分利用膨胀珍珠岩(expanded perlite,简称EP)的多孔吸水性,局部分离淤泥中的自由水,使其变为不均匀分布,营造泥-水分离的固化环境。试验发现,掺入EP可以有效提高固化淤泥的无侧限抗压强度(unconfined compressive strength,简称UCS),但其掺入方式影响固化强度的增长速率和孔隙分布特征。焖料方式最有利于提升固化效果,即把EP先掺入到淤泥中,混合24 h后再加水泥固化;养护28 d时,焖料试样的强度是直接固化试样(EP掺入后直接加水泥固化)强度的1.56倍,是仅掺入水泥固化试样强度的2.15倍,说明EP营造的局部泥-水分离环境可有效提高固化淤泥的强度。同时,水化热试验结果表明,EP促进了水泥水化作用。EP-淤泥固化土的孔隙分布曲线和表观形貌照片显示,虽然掺入EP引入了气孔,但也为水化产物提供了生长空间,使得淤泥和EP界面形成嵌入式胶结,共同构成固化土骨架。EP调控淤泥含水率属于物理方法,方便快捷,并且EP是高硅轻骨料,与淤泥相容性好,兼具环境友好性。High water content in dredged silt leads to elevated costs for drying and solidification.By fully utilizing the porous water absorption of Expanded Perlite(EP),we can locally separate free water from the silt,resulting in an uneven water distribution and creating a“silt-water separation”solidification environment.Experimental results indicate that incorporating EP with silt can effectively enhance the unconfined compressive strength(UCS)of the solidified silt,but the method of incorporation affects the rate of strength increase and pore distribution.The stewing method,which involves pre-mixing EP into the silt and then adding cement after 24 hours,proves most favorable for promoting the solidification effect.After 28 days of curing,the strength of the stewing sample is 1.56 times that of the sample directly solidified with cement after EP incorporation,and 2.15 times that of the sample solidified with cement only.This indicates that the local"silt-water separation"effect facilitated by EP can effectively enhance the strength of the solidified silt.Meanwhile,hydration heat test results show that EP promotes cement hydration.According to the pore distribution curve and surface morphology images of EP-silt-solidified soil,while EP introduces porosity,it also provides growth space for hydration products,resulting in an embedded bond that forms a solidified soil skeleton between the interface of silt and EP.The method of regulating water content using EP is a physical one,which is convenient and efficient,differing from energy-intensive methods like machinery.Additionally,as a high-silica lightweight aggregate,EP exhibits good compatibility with silt and is environmentally friendly.

关 键 词：高含水率淤泥 膨胀珍珠岩 泥-水分离 内养护 

分 类 号：TU411[建筑科学—岩土工程]