检索结果-南通市图书馆

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

钙溶蚀对混凝土抗氯离子侵蚀性能的影响

材料导报 2024年第16期38卷 126-132页

作者：王少伟肖焰钰朱平华严先萃夏群常州大学城市建设学院江苏常州213164

面板堆石坝和水下隧道等构筑物因渗漏水而容易遭受钙溶蚀病害,在复杂水环境下将面临钙溶蚀和氯离子侵蚀耦合作用下的混凝土耐久性问题。采用化学溶液浸泡法,对不同水灰比混凝土开展了耦合加速腐蚀试验,研究了钙溶蚀和氯离子侵蚀评价指... 详细信息

面板堆石坝和水下隧道等构筑物因渗漏水而容易遭受钙溶蚀病害,在复杂水环境下将面临钙溶蚀和氯离子侵蚀耦合作用下的混凝土耐久性问题。采用化学溶液浸泡法,对不同水灰比混凝土开展了耦合加速腐蚀试验,研究了钙溶蚀和氯离子侵蚀评价指标的时空演变规律,量化了钙溶蚀对混凝土抗氯离子侵蚀性能的影响,并对其微观机理进行了解释。结果表明:混凝土完全溶蚀后的氯离子扩散系数和氯离子含量分别是未溶蚀状态下的3.5倍左右和1.3~2.0倍;扩散系数在溶蚀区由表及里呈线性衰减趋势,但在深度越大处,氯离子含量的增大倍率也越大;溶蚀混凝土的氯离子吸附能力呈明显增强的趋势,且仍遵循线性吸附模型;混凝土水灰比越大,其抗溶蚀和抗氯离子侵蚀性能越差。

关键词：混凝土钙溶蚀氯离子侵蚀加速效应

Effect of Fatigue Loading on the Mechanical Properties and Resistance of High-strength Straight-hole Recycled Pervious Concrete to Rainstorm-based Waterlogging

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2023年第1期38卷 141-148页

作者：朱平华 FAN Haifeng yan xiancui LIU Hui WANG Xinjie CHEN Chunhong Department of Civil Engineering Changzhou UniversityChangzhou 213164China

A novel high-strength straight-hole recycled pervious concrete(HSRPC)for the secondary highway pavement was prepared in this *** study aimed to investigate the effect of porosity(0.126%,0.502%,and 1.13%),vehicle loading stress level(0.5 and 0.8)and service life on the resistance to rainstormbased waterlogging of HSRPC under fatigue *** mechanical properties of HSRPC in terms of flexural strength and dynamic elastic modulus were *** waterlogging resistance of HSRPC was described by surface water depth and drainage *** microstructure of HSRPC were observed with scanning electron microscopy(SEM).Results showed that although the dynamic elastic modulus and flexural strength of HSRPC decreased with the increasing number of fatigue loading,the flexural strength of HSRPC was still greater than5 MPa after design service life of 20 *** 2.5×10^(5)times of fatigue loading,the permeability coefficient of HSRPC with a porosity of 0.502%and 1.13%increased by 18.4%and 22.9%,respectively;while the permeability coefficient of HSRPC with 0.126%porosity dropped to 0.35 mm/*** maximum surface water depth of HSRPC with a porosity of 0.126%,0.502%,and 1.13%were 8,5 and 4 mm,*** results showed that fatigue loading expanded the number and width of cracks around the tiny pores in HSRPC.

关键词： recycled pervious concrete porosity fatigue loading service life stress level rainstorm and waterlogging

Pore Characteristic Design Method of High-strength Pervious Concrete Based on the Mechanical Properties and Rainstorm Waterlogging Resistance

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2023年第3期38卷 567-574页

作者：朱平华 SHI Zhihao LIU Hui yan xiancui yanG Lei ZONG Meirong Department of Civil Engineering Changzhou UniversityChangzhou 213164China

High-strength pervious concrete(HSPC) with porosity ranging from 0.08% to 2.011% was prepared. The mechanical properties and rainstorm waterlogging resistance of HSPC were evaluated,and a design method of HSPC pore characteristics(porosity and pore diameter) based on the mechanical properties and rainstorm waterlogging resistance was proposed. The results showed that the reduction of effective cross-sectional area caused by artificial channels was the main factor affecting flexural strength but had limited influence on compressive strength. Compared with the concrete matrix without artificial channels,the compressive strength of HSPC with porosity of 2.011% decreased by 7.4%, while the flexural strength decreased by 48.3%. The permeability coefficient of HSPC can reach 16.35 mm/s even at low porosity(2.011%).HSPC can meet the requirements of no rainstorm waterlogging, even if exposed to 100-year rainstorms. When the mechanical properties and rainstorm waterlogging resistance are compromised, the recommended porosity ranges from 1.1% to 3.5%, and the recommended pore diameter ranges from 0.8 to 2.7 mm.

关键词： pervious concrete artificial channel pore characteristic permeability coefficient rainstorm waterlogging

Effect of CO_(2) Curing on the Physical Properties of Recycled Coarse Aggregate with Different Attached Mortar Contents

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2022年第5期37卷 905-911页

作者： ZHU Pinghua LI Haichao LIU Hui yan xiancui WANG Xinjie CHEN Chunhong Department of Civil Engineering Changzhou UniversityChangzhou213164China

The effects of carbon dioxide (CO_(2)) curing conditions (temperature,relative humidity and CO_(2) curing time) on the physical properties of recycled coarse aggregate (RCA) with varying attached mortar (AM) contents were *** and after CO_(2) curing,the physical properties in terms of the apparent density,water absorption and crushing value of RCA were tested and the quality of RCA was ***,scanning electron microscope was used to observe the microstructure of *** show that the physical properties variation of RCA with higher AM content are more significant,and the quality of RCA with lower AM content is easier to be upgraded during CO_(2) *** physical properties of RCA with 40.8% AM content are earlier stable than that with no less than 44.5% AM content during CO_(2) *** optimal temperature and relative humidity are 50 ℃ and 55% for CO_(2) curing,***_(2) curing is incapable of upgrading the quality of RCA with AM no less than 50.6%.The quality of RCA with 44.5% AM content can be upgraded only under the optimum CO_(2) curing *** relative humidity higher than 40% and the CO_(2) curing time more than 12 h,CO_(2) curing upgrades the quality of RCA with 40.8% AM content.

关键词： recycled coarse aggregate attached mortar content carbon dioxide curing curing time relative humidity temperature

Effect of High Temperature Curing on the Frost Resistance of Recycled Aggregate Concrete and the Physical Properties of Second-Generation Recycled Coarse Aggregate under Freeze-Thaw Cycles

在线全文

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2023年第6期11卷 2953-2967页

作者： Xintong Chen Pinghua Zhu xiancui yan Lei yang Huayu Wang Changzhou City Key Laboratory of Building Energy-Saving Technology Department of Civil EngineeringChangzhou UniversityChangzhou213164China

With the emphasis on environmental issues,the recycling of waste concrete,even recycled concrete,has become a hot spot in the field of *** the repeated recycling of waste concrete used in harsh environments is still a complex *** paper discusses the durability and recyclability of recycled aggregate concrete(RAC)as a prefabricated material in the harsh environment,the effect of high-temperature curing(60℃,80℃,and 100℃)on the frost resistance of RAC and physical properties of the second generation recycled coarse aggregate(RCA_(2))of RAC after 300 freeze-thaw cycles were *** frost resistance of RAC was characterized by compressive strength,relative dynamic elastic modulus,and mass *** the physical properties of RCA_(2),the apparent density,water absorption,and crushing value were *** the SEM images of RAC after 300 freeze-thaw cycles were *** results indicated that the frost resistance of RAC cured at 80℃ for 7 days was comparable to that cured in the standard condition(cured for 28 days at 20℃±2℃ and 95%humidity),and the RAC cured at 100℃ was slightly ***,the frost resistance of RAC cured at 60℃ deteriorated *** RAC cured at 80℃ for 7 days is the *** after the freeze-thaw cycle or not,the RCA that curd at 60℃,80℃,and 100℃ for 7 days can also meet the requirements of Grade III RCA and be used as the aggregate of non-bearing part of prefabricated concrete ***_(2) which is cured at 80℃ for 7 days had the best physical properties.

关键词： Freeze-thaw cycles curing condition recycled aggregate concrete second-generation recycled coarse aggregate

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

暴雨作用下新型再生透水混凝土的抗堵塞性能

建筑材料学报 2023年第10期26卷 1088-1095页

作者：朱平华史志浩严先萃杨磊宗美荣常州大学城市建设学院江苏常州213164

通过暴雨堵塞试验,研究了新型再生透水混凝土(NRPC)的抗堵塞性能,分析了NRPC孔径(d)和堵塞物粒径(r)对NRPC堵塞结构、透水系数、堵塞深度和堵塞物通过率的影响.结果表明:NRPC形成的堵塞结构由孔径和堵塞物粒径的比值(d/r)共同决定,暴雨... 详细信息

通过暴雨堵塞试验,研究了新型再生透水混凝土(NRPC)的抗堵塞性能,分析了NRPC孔径(d)和堵塞物粒径(r)对NRPC堵塞结构、透水系数、堵塞深度和堵塞物通过率的影响.结果表明:NRPC形成的堵塞结构由孔径和堵塞物粒径的比值(d/r)共同决定,暴雨作用后的堵塞结构分为单颗粒表面堵塞、单颗粒孔道堵塞和多颗粒孔道堵塞;透水系数的降低主要发生在第1次暴雨堵塞循环中,小粒径堵塞物(r r时,d/r越小,NRPC孔道堵塞的深度越大;随着d/r的增加,堵塞物的通过率不断增加,孔道的筛选作用降低.

关键词：透水混凝土孔道堵塞透水系数孔径堵塞物粒径

高延性水泥基复合材料与既有混凝土结合面的抗溶蚀性

在线全文

学校读者我要写书评

暂无评论

硅酸盐学报 2022年第10期50卷 2692-2700页

作者：王少伟肖焰钰朱平华严先萃吕奇峰常州大学环境与安全工程学院江苏常州213164

针对触水混凝土结构补强加固中高延性水泥基复合材料(ECC)与既有混凝土结合面的抗溶蚀性,采用0.5 mol/L的硝酸溶液对含结合面的ECC-既有混凝土复合试件进行加速溶蚀实验,研究既有混凝土界面凿毛、湿饱和及涂刷界面剂3种处理方式对结合... 详细信息

针对触水混凝土结构补强加固中高延性水泥基复合材料(ECC)与既有混凝土结合面的抗溶蚀性,采用0.5 mol/L的硝酸溶液对含结合面的ECC-既有混凝土复合试件进行加速溶蚀实验,研究既有混凝土界面凿毛、湿饱和及涂刷界面剂3种处理方式对结合面黏结强度、溶蚀深度和钙溶蚀量3种评价指标的时变影响规律,并通过扫描电子显微镜对结合面抗溶蚀性提升效果进行微观机理分析。结果表明:3种界面处理方式均能有效提高结合面的初始黏结强度和抗溶蚀性,且对溶蚀过程的时变影响规律基本一致,可用溶蚀前的黏结强度评价结合面的抗溶蚀性;凿毛对提升结合面初始黏结强度最有效,而界面剂更有利于减缓溶蚀过程中界面处理提升效果的劣化速度;组合处理模式下各界面处理方式的单一提升效果明显优于其单独使用时,且组合的其它处理方式越多,优势越明显;环氧树脂界面剂的提升效果略优于水泥净浆界面剂。

关键词：结合面界面处理黏结强度抗溶蚀性

养护方式对纳米氧化镁水泥浆体强度的影响研究

在线全文

学校读者我要写书评

暂无评论

混凝土 2017年第9期 40-44页

作者：宋诗琦蒋林华姜少博严先萃河海大学力学与材料学院江苏南京210098

采用纳米氧化镁(Nano-MgO)替代常规MgO类膨胀剂掺入水泥浆体中,以期望能够提高水泥浆体的抗折、抗压强度。采用不同的养护方式、养护温度和水灰比进行试验,试验中借助了X射线衍射(XRD)等微观测试技术研究其机理。试验结果表明:掺入Nano-... 详细信息

采用纳米氧化镁(Nano-MgO)替代常规MgO类膨胀剂掺入水泥浆体中,以期望能够提高水泥浆体的抗折、抗压强度。采用不同的养护方式、养护温度和水灰比进行试验,试验中借助了X射线衍射(XRD)等微观测试技术研究其机理。试验结果表明:掺入Nano-MgO可以提高水泥浆体的抗折、抗压强度;适当的提高养护温度有助于浆体强度的增长;同等条件下,饱和氢氧化钙溶液养护和蒸汽养护对强度发展更加有益;相同掺量时,水灰比增大,其强度呈现下降趋势;XRD图谱反映出适当的提高养护温度,Nano-MgO水泥浆体水化更充分,试验对象的强度也随之提升。

关键词： Nano—MgO 养护方式养护温度水灰比力学强度

不同BMI体检人群甲状腺结节检出情况和影响因素分析

在线全文

学校读者我要写书评

暂无评论

齐齐哈尔医学院学报 2023年第10期44卷 972-978页

作者：刘雅思张先翠谢郁芳陶梦君武艳皖南医学院研究生学院安徽芜湖241000 皖南医学院第一附属医院健康管理中心

目的探讨不同身体质量指数(BMI)体检人群甲状腺结节检出情况及影响因素分析,为临床甲状腺结节的防治提供指导。方法选取2021年7—12月本院健康管理中心的2699例健康体检人群作为研究对象。记录一般情况、甲状腺超声检查结果、BMI和相关... 详细信息

目的探讨不同身体质量指数(BMI)体检人群甲状腺结节检出情况及影响因素分析,为临床甲状腺结节的防治提供指导。方法选取2021年7—12月本院健康管理中心的2699例健康体检人群作为研究对象。记录一般情况、甲状腺超声检查结果、BMI和相关生化检查结果。通过比较不同BMI分级和生化指标,分析不同BMI人群的甲状腺结节检出情况,并通过Logistic回归分析甲状腺结节的危险因素。结果本研究共纳入2699名体检人群,男825名,女1874名。甲状腺结节男性检出率(40.56%)低于女性检出率(54.80%),差异有统计学意义(P<0.05)。不同BMI分组中,男性超重组甲状腺结节检出率最高(42.59%),女性肥胖组甲状腺结节检出率最高(62.69%)。在甲状腺结节阴性组和阳性组生化指标的分析中,男性甲状腺组血清游离三碘甲腺原氨酸(FT3),正常的促甲状腺激素(TSH)、空腹血糖、甘油三酯均高于非甲状腺组,差异有统计学意义(P<0.05);女性甲状腺组的空腹血糖、总胆固醇、甘油三酯、低密度脂蛋白、尿酸均高于非甲状腺组,差异有统计学意义(P<0.05)。Logistic回归分析结果显示,性别,BMI,尿酸,血糖为甲状腺结节的独立影响因素。结论肥胖组和超重组甲状腺结节检出率最高,控制体重对于甲状腺结节的防治有一定的作用。

关键词：体检人群 BMI 甲状腺结节影响因素