搅拌站废水含固量对混凝土强度及微观结构影响研究  

Study on recycling of wastewater concrete with different solids content

作　　者：吴瑾 陈徐东[1] 宁英杰 张伟[2,4] WU Jin;CHEN Xudong;NING Yingjie;ZHANG Wei(College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China;College of Water Resources and Hydropower,Hohai University,Nanjing 210098,China;Zhejiang Communications Construction Group Co.,Ltd.,Hangzhou 310051,China;Yangzhou Water Resources Bureau,Yangzhou 225000,China)

机构地区：[1]河海大学土木与交通学院,江苏南京210098 [2]河海大学水利水电学院,江苏南京210098 [3]浙江交工集团股份有限公司,浙江杭州310051 [4]扬州水利局,江苏扬州225000

出　　处：《混凝土》2023年第9期163-167,共5页Concrete

基　　金：国家重点研发计划(2021YFB2600200);国家自然科学基金面上项目(51979090);国家重点实验室开放基金(2019CEM002)。

摘　　要：利用预拌混凝土搅拌站洗涮废水取代混凝土拌和用水对废水进行再利用。通过抗压强度试验与劈裂抗拉强度试验分析了废水中含固量(0、1%、2%、3%、4%)对混凝土强度的影响,采用压汞法(MIP)、真空电镜扫描技术(SEM)和X衍射技术(XRD)对废水混凝土的孔隙结构、微观形貌与水化产物结合其宏观力学性能进行了分析。结果表明:废水在含固量较低时,对混凝土强度有不利影响,当废水中含固量相对较高时,其孔隙率小于或接近对照组混凝土试件的孔隙率,废水中的活性物质对混凝土强度的促进作用强于其中有害物质对混凝土的负面影响,强度与对照组混凝土接近。试验表明,含固量大于或等于3%的废水可以用于完全取代自来水用于制备混凝土。Wastewater was reused by replacing concrete mixing water with wastewater from commercial concrete mixing plants.The effects of solids content(0,1%,2%,3%,4%)in wastewater on the strength of concrete were analyzed by compressive strength test and splitting tensile strength test,and the pore structure,microscopic morphology and hydration products of wastewater concrete combined with its macroscopic mechanical properties were analyzed by mercury-pressure method(MIP),vacuum electron microscopy scanning technique(SEM)and X diffraction technique(XRD).The results showed that the wastewater had a negative effect on the concrete strength when the solid content was low,and when the solid content in the wastewater was relatively high,its porosity was smaller than or close to that of the concrete specimens in the control group,and the active substances in the wastewater had a stronger promotion effect on the concrete strength than the negative effect of the harmful substances in it on the concrete,and the strength was close to that of the control concrete.The test showed that wastewater with solids content greater than or equal to 3%can be used to completely replace tap water for concrete preparation.

关 键 词：搅拌站废水 含固量 抗压强度 劈裂抗拉强度 微观结构 

分 类 号：TU528.01[建筑科学—建筑技术科学]