Influence of waste glass on concrete strength and permeability during dry-wet cycles
作者：
Zhang, Xuebing;Quan, Yang;Cao, Guohui;Tang, Shenghua;Ou, Wanji;...
期刊：
European Journal of Environmental and Civil Engineering ,2024年 ISSN：1964-8189
通讯作者：
Xiang, P
作者机构：
[Quan, Yang; Ou, Wanji; Tang, Shenghua; Chen, Baikuang; Wang, Zhichao; Zhang, Xuebing; Cao, Jun; Liu, Luoqing] Xiangtan Univ, Coll Civil Engn, Xiangtan, Hunan, Peoples R China.;[Cao, Guohui] Hunan City Univ, Coll Civil Engn, Yiyang, Hunan, Peoples R China.;[Xiang, Ping; Xiang, P] Cent South Univ, Sch Civil Engn, Changsha 410075, Hunan, Peoples R China.;[Xiang, Ping] Taishan Univ, Sch Civil Engn, Tai An, Shandong, Peoples R China.
通讯机构：
[Xiang, P ] C;Cent South Univ, Sch Civil Engn, Changsha 410075, Hunan, Peoples R China.
关键词：
Dry-wet cycles;waste glass;strength;permeability
摘要：
A series of experiments were carried out to explore the impact of waste glass on the durability of concrete. In this study, waste glass was incrementally incorporated to replace sand as the fine aggregate in creating 240 concrete specimens, with substitution rates of 0%, 10%, 30%, and 50%. The concrete specimens were subjected to early strength testing on the 3rd and 7th day, followed by evaluation of strength and permeability after curing for 28 days with dry-wet cycles. Furthermore, ultrasonic wave analysis was conducted on the waveform, and the concrete's internal phases and chemical composition were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS). The results led to the following observations: (1) The inclusion of glass sand lowered the early compressive strength of concrete, with the lowest drop being 24.78%. However, when it was cured for 28 days and the content of glass sand was not more than 30%, the change rate of its compressive strength was between -2.85% and 3.19%, so it was practically negligible. (2) Glass sand substitution rates ranging from 10% to 30% greatly enhanced the strength of concrete under dry-wet cycles, and the 50% substitution rate significantly improved the permeability properties, although it adversely affected the strength.
语种：
英文
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腐蚀与荷载耦合作用下混凝土柱徐变机理研究
作者：
廖世杰;曹国辉;王礼彬;肖勇刚
期刊：
湖南城市学院学报(自然科学版) ,2023年32(01):1-5 ISSN：1672-7304
作者机构：
[肖勇刚; 王礼彬; 廖世杰] 长沙理工大学土木工程学院;[曹国辉] 湖南城市学院土木工程学院
关键词：
钢筋混凝土柱;钢筋不均匀锈蚀;徐变;修正系数法
摘要：
为了研究腐蚀与荷载耦合作用下钢筋混凝土柱的徐变行为，分别对轴压、小偏压和大偏压3种受力状态的钢筋混凝土柱进行了腐蚀与荷载共同作用下的长期性能试验，并结合试验提出了不同钢筋锈蚀状况下的理论徐变修正模型.研究结果表明：钢筋混凝土柱在相同受力状态下，当钢筋轻度腐蚀时的混凝土徐变略低于未锈蚀试件；当钢筋为重度腐蚀时，相较于未锈蚀试件，混凝土徐变出现了较大增长；经验证，实测值与模型理论值吻合较好.
语种：
中文
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栓钉锈蚀后钢-混凝土组合梁抗弯性能试验研究
作者：
曹国辉;曹一青;周超;李海
期刊：
铁道学报 ,2022年44(11):129-135 ISSN：1001-8360
作者机构：
[曹国辉] 湖南城市学院土木工程学院,湖南益阳 413000;[曹国辉] 湘潭大学土木工程学院,湖南湘潭 411100;长沙理工大学土木工程学院,湖南长沙 410000;[周超] 长沙理工大学;[李海] 湖南城市学院
关键词：
钢-混凝土组合梁;栓钉锈蚀;极限承载力试验;抗弯性能;挠度计算方法
摘要：
对腐蚀与长期荷载耦合作用后的钢-混凝土组合梁进行了极限承载力试验,研究了栓钉锈蚀与长期荷载对组合梁极限承载力、跨中挠度、界面相对滑移的影响.研究结果表明,栓钉锈蚀后,组合梁跨中挠度和界面相对滑移增大,极限承载力降低.与未锈蚀试件相比,锈蚀试件极限承载力降低了 0.5％～5.4％,160 kN荷载作用下的跨中挠度增加了 8.2％～47.5％,120 kN荷载作用下最大界面相对滑移增加了 34.6％～50.8％.与无长期荷载试件相比,有长期荷载试件极限承载力无明显降低,160 kN荷载作用下的跨中挠度增加了 16.1％～19.0％,120 kN荷载作用下的最大界面相对滑移增加了 18.3％～31.8％.考虑滑移效应的影响,提出栓钉锈蚀条件下钢-混凝土组合梁挠度计算方法,与试验结果比较,组合梁挠度理论值与实测值吻合较好,可为工程实际应用提供参考.
语种：
中文
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氯盐环境与荷载耦合作用下加载龄期对钢筋混凝土柱徐变影响
作者：
曹国辉;王礼彬;张展维
期刊：
建筑结构学报 ,2022年43(6):275-283 ISSN：1000-6869
作者机构：
[曹国辉] College of Civil Engineering, Hunan City University, Yiyang, 413000, China;[王礼彬] College of Civil Engineering, Changsha University of Science & Technology, Changsha, 410000, China;[张展维] College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan, 411105, China
关键词：
RC柱;早龄期混凝土;钢筋不均匀锈蚀;静力试验;徐变
摘要：
为研究氯盐环境与荷载耦合作用下钢筋混凝土柱的徐变效应,在持荷与氯盐腐蚀环境下,对18根早龄期与标准龄期钢筋混凝土柱进行了 202 d的长期试验,钢筋锈蚀率分别为0％、10％、20％,测试了早龄期混凝土柱在轴压、小偏压、大偏压三种受力状态下的徐变行为,并与相同条件下标准龄期混凝土柱的徐变行为进行了对比.结果表明:钢筋锈蚀率为10％时,锈蚀RC柱的徐变系数略低于未锈蚀RC柱的;钢筋锈蚀率为20％时,锈蚀RC柱的早期徐变系数偏低,而后期徐变系数出现较快且持续的增长;受混凝土黏性流动和钢筋锈蚀影响,早龄期RC柱的徐变系数低于理论值.根据钢筋实际锈蚀状况,拟合了钢筋锈蚀率分布函数,并通过黏结退化系数得出对应的徐变折减系数,提出修正的ACI209R徐变模型.通过与试验数据进行对比分析,该修正徐变模型的预测效果较好.当锈蚀率为10％时,模型可靠性高;当锈蚀率为20％时,在持载早期,模型计算值较实测值偏高,但后期两者的差值较小.
语种：
中文
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膨胀剂对钢管混凝土圆柱轴压承载能力试验研究
作者：
陈咏明;曹国辉
期刊：
建筑结构 ,2022年52(S1):1355-1359 ISSN：1002-848X
作者机构：
湖南城市学院土木工程学院
关键词：
圆柱;轴心受压;承载能力;膨胀剂;养护龄期
摘要：
通过8根素混凝土、钢筋混凝土、钢管混凝土和钢管膨胀混凝土圆柱体在各级荷载等级下轴压力学性能试验，研究了不同养护龄期、膨胀剂对上述构件轴压极限承载能力的影响。结果表明：钢管混凝土圆柱在弹性变形阶段轴力主要由核心混凝土承压，钢管膨胀混凝土由钢管和核心混凝土共同承压，钢管膨胀混凝土圆柱持荷全过程表现出明显弹塑性阶段。钢管膨胀混凝土极限承载能力大于钢管混凝土和钢筋混凝土极限承载能力，掺合膨胀剂可有效改善钢管混凝土受力性能。养护龄期和膨胀剂成为素混凝土圆柱极限承载能力两个非常关键因素，且对素混凝土圆柱极限承载能力均起到加强作用，膨胀剂在钢管混凝土圆柱极限轴压力学性能中起主导作用，养护龄期对钢管混凝土圆柱轴压承载能力影响不大。
语种：
中文
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栓钉锈蚀情况下组合梁极限承载力的一种计算方法
作者：
王礼彬;邱杰;黄柳;曹国辉
期刊：
湖南城市学院学报(自然科学版) ,2021年30(03):17-20 ISSN：1672-7304
作者机构：
[王礼彬] 长沙理工大学土木工程学院;[曹国辉; 黄柳; 邱杰] 湖南城市学院土木工程学院
关键词：
钢-混凝土组合梁;栓钉锈蚀;抗剪连接程度
摘要：
为了研究栓钉锈蚀对组合梁极限承载力的影响,通过对栓钉锈蚀率不同的钢-混凝土组合梁进行极限承载力破坏试验,对试验结果进行理论分析,并基于组合梁的不完全抗剪连接理论,提出了栓钉锈蚀后组合梁极限承载力计算公式.结果表明:栓钉锈蚀将导致组合梁的极限承载力降低,且极限承载力随着栓钉锈蚀率的增加呈线性下降趋势;将栓钉锈蚀率与组合梁抗剪连接系数相关联,提出栓钉锈蚀情况下组合梁极限承载力计算模型,该模型计算值与试验值吻合良好.
语种：
中文
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不同开裂状态下预应力混凝土连续箱梁受力性能评估试验研究
作者：
李克忠;曹国辉;杨李根
期刊：
中南大学学报(自然科学版) ,2020年51(12):3475-3483 ISSN：1672-7207
通讯作者：
Cao, Guohui(cgfcivil@163.com)
作者机构：
[李克忠] Hunan University Design and Research Institute Co. Ltd., Changsha;410082, China;Changsha Huayi Engineering Design Co. Ltd., Changsha;410000, China;[曹国辉] School of Civil Engineering, Hunan City University, Yiyang
关键词：
预应力混凝土连续箱梁;开裂;修正系数;承载能力
摘要：
为了对不同开裂状态下预应力混凝土连续箱梁桥的承载能力进行快速估算,对比例尺为1:4的三跨预应力混凝土连续梁模型进行荷载试验,将特征截面(支点、1/4跨、1/2跨截面)混凝土应力、应变及梁体跨中挠度的试验实测结果与弹性计算结果和非线性计算结果进行分析、对比,验证模型桥实测结果的可靠性,并根据这三者的关系得出基于弹性理论估算开裂结构受力状态的修正系数;根据公路桥涵设计规范的裂缝宽度计算公式,取修正系数C_3 = 1.25计算裂缝最大宽度W_(ft),通过各级荷载作用下模型裂缝宽度W_1与 W_(ft)的比值(W_1/W_(ft))和对应的截面弯矩承载率(M_1/M_u)之间的关系,提出裂缝宽度比与承载率的函数关系式。研究结果表明:结构开裂后,估算混凝土连续箱梁桥挠度时修正系数可取1.5~2.0,估算应力时修正系数可取1.5~2.5;本研究所得的裂缝宽度比与承载率的函数关系式和挠度、应力修正系数可对桥梁承载能力和安全性进行初步估算和评估。
语种：
中文
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An experimental study on the flexural behavior of local prestressed steel–concrete composite continuous box beams
作者：
Zhang, Xuebing;Zhang, Zhanwei;Cao, Guohui* ;Mo, Dongshan
期刊：
Advances in Structural Engineering ,2020年24(2):307-319 ISSN：1369-4332
通讯作者：
Cao, Guohui
作者机构：
[Zhang, Zhanwei; Mo, Dongshan; Zhang, Xuebing] Xiangtan Univ, Coll Civil Engn & Mech, Xiangtan, Hunan, Peoples R China.;[Cao, Guohui] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.
通讯机构：
[Cao, Guohui] H;Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.
关键词：
composite continuous box beam;deflection;local prestressing;redistribution of internal forces;slip
摘要：
The flexural bearing capacities of three composite continuous box beams with different prestressing degrees were tested and studied to investigate the influences of local prestressing bundles on the deflection, relative slip of interface, strain, and redistribution of the internal force of the steel–concrete composite continuous box beam. Results show that the arrangement of local prestress can not only improve the bending stiffness at the mid-span of the composite continuous box beam, but also significantly enhance the ductility. In the design process of the local prestressed composite continuous box beam, the influence of the slip at the middle support should be fully considered, and the deflection could not be taken as a control factor. The internal force redistribution of the local prestressed continuous box beam is lower than that of the ordinary continuous box beam, but it still has good plastic internal force redistribution. The number of prestressing bundles in the negative moment region is the main factor that affects the internal force redistribution of the middle support. © The Author(s) 2020.
语种：
英文
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钢筋锈蚀条件下混凝土柱有效弹性模量试验研究
作者：
曹国辉;韩传昌;邓昂;唐皇
期刊：
实验力学 ,2019年34(3):509-516 ISSN：1001-4888
作者机构：
湖南城市学院土木工程学院,湖南益阳413000;湘潭大学土木工程与力学学院,湖南湘潭411105;湘潭大学土木工程与力学学院,湖南湘潭,411105;湖南城市学院土木工程学院,湖南益阳,413000;[邓昂; 韩传昌] 湘潭大学
关键词：
钢筋锈蚀;有效弹性模量;配筋率;混凝土柱;计算模型
摘要：
通过对16根钢筋混凝土柱进行腐蚀与长期荷载共同作用的长期试验,研究构件在不同配筋率、钢筋锈蚀率及加载龄期下有效弹性模量的变化规律,配筋率分别为1%、2%、3%,钢筋锈蚀率分别为0%、10%、20%,加载龄期分别为7d和28d。研究结果表明:配筋率与加载龄期对钢筋混凝土有效弹性模量都有影响,两种影响具有叠加效应,并且这种叠加效应不只是简单的线性叠加;钢筋锈蚀率越大,钢筋混凝土有效弹性模量越小。在试验研究的同时,还提出了考虑配筋率与钢筋锈蚀率的混凝土柱有效弹性模量计算模型,通过模型计算值与试验值的相对误差对比,验证了本文计算模型的有效性和适用性。
语种：
中文
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Long-Term Experimental Study on Prestressed Steel-Concrete Composite Continuous Box Beams
作者：
Cao, Guohui* ;Han, Chuanchang;Dai, Ye;Zhang, Wang
期刊：
Journal of Bridge Engineering ,2018年23(9):04018067 ISSN：1084-0702
通讯作者：
Cao, Guohui
作者机构：
[Cao, Guohui; Han, Chuanchang] Xiangtan Univ, Coll Civil Engn & Mech, North Second Ring Rd, Xiangtan 411105, Hunan, Peoples R China.;[Cao, Guohui] Hunan City Univ, Coll Civil Engn, 518,Yingbin East Rd, Yiyang 413000, Hunan, Peoples R China.;[Dai, Ye; Zhang, Wang] Changsha Univ Sci & Technol, Sch Civil Engn & Architecture, 960,2nd Sect,Wanjiali South Rd, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Cao, Guohui] X;[Cao, Guohui] H;Xiangtan Univ, Coll Civil Engn & Mech, North Second Ring Rd, Xiangtan 411105, Hunan, Peoples R China.;Hunan City Univ, Coll Civil Engn, 518,Yingbin East Rd, Yiyang 413000, Hunan, Peoples R China.
关键词：
Concrete beams and girders;Concrete slabs;Creep;Deflection (structures);Growth rate;Prestressed beams and girders;Prestressing;Shrinkage;Steel testing;Box beam;Effective moduli;Internal force redistribution;Long term performance;Shrinkage and creep;Concrete testing
摘要：
A long-term load test of 420 days was performed on three prestressed steel-concrete composite continuous box beams (non-prestressed, partly prestressed, and fully prestressed) to investigate the combined effects of sustained load, shrinkage, creep, and prestressing. Several time-varying parameters, such as deflection, concrete strain, prestressing force, support reaction, and relative slippage between the concrete slab and the steel box beam, were monitored in the test. The long-term performance of the prestressed beams that was developed using a special law increased and decreased the support reactions at the middle and end piers over time, respectively, due to the distinct configuration of prestressed strands (i.e., installation was only at the negative moment area). The growth rate of the deflection of the prestressed beams was slightly greater than that of the deflection of the non-prestressed beam. Moreover, cracking at the negative moment region significantly accelerated the development of the relative slippage of the non-prestressed beam. A calculation model of long-term deflection based on classical theories was proposed to theoretically analyze the measured data and provide valuable insights for future research. © 2018 American Society of Civil Engineers.
语种：
英文
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长期荷载作用下锈蚀栓钉连接件卸载后静力试验研究
作者：
熊辉;阳亮;曹国辉
期刊：
铁道科学与工程学报 ,2018年15(6):1524-1533 ISSN：1672-7029
作者机构：
湖南大学土木工程学院, 湖南, 长沙, 410082;湖南城市学院土木工程学院, 湖南, 益阳, 413000;[熊辉; 阳亮] 湖南大学土木工程学院, 湖南, 长沙, 410082;[曹国辉] 湖南城市学院土木工程学院, 湖南, 益阳, 413000
关键词：
抗剪连接件;推出试验;栓钉锈蚀;耦合作用;荷载-滑移曲线
摘要：
通过8个标准连接件的推出试验,研究长期荷载卸载后锈蚀栓钉连接件的静力性能,了解长期荷载与栓钉锈蚀对连接件抗剪承载力、荷载-滑移曲线及变形能力的影响。试验结果表明:推出试验中,栓钉经历了先受压再受拉最后剪断3个受力阶段,栓钉受压处混凝土应变远远高于周边混凝土,随着荷载的增加,连接件刚度处在一个加速退化的状态;腐蚀与荷载存在耦合作用,对于栓钉受拉侧,腐蚀与荷载耦合加速栓钉锈蚀,对于栓钉受压侧,腐蚀与荷载耦合抑制栓钉锈蚀;长期荷载加速初始滑移的发展,但对试件最终滑移量及承载力影响不大,栓钉锈蚀降低试件刚度,加大滑移发展速率,降低极限承载力,对最终滑移量影响显著。最后,通过参数拟合方法建立锈蚀栓钉连接件抗剪承载力及荷载-滑移曲线计算公式,拟合结果表明,计算公式能够较准确地计算锈蚀栓钉连接件的抗剪承载力、滑移终值及荷载-滑移曲线,可为组合结构锈蚀计算提供参考。
语种：
中文
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Long-term mechanical properties of steel-concrete connectors subjected to corrosion and load coupling
作者：
Cao, Guohui* ;Yang, Liang;Zhang, Wang;Peng, Xirong;Dai, Ye
期刊：
Journal of Materials in Civil Engineering ,2018年30(5) ISSN：0899-1561
通讯作者：
Cao, Guohui
作者机构：
[Peng, Xirong; Cao, Guohui] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.;[Yang, Liang] Hunan Univ, Coll Civil Engn, Changsha 410082, Hunan, Peoples R China.;[Dai, Ye; Zhang, Wang] Changsha Univ Sci & Technol, Sch Civil Engn & Architecture, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Cao, Guohui] H;Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.
关键词：
Bridges;Composite structures;Concrete slabs;Concretes;Corrosion;Couplings;Creep;Deformation;Elastic moduli;Shrinkage;Sodium chloride;Specifications;Structure (composition);Studs (fasteners);Studs (structural members);Environmental corrosions;Long term performance;Mechanical behavior;Modern buildings;Shear connector;Shrinkage and creep;Steel concrete composite structures;Structural durability;Rigid structures;concrete;corrosion;creep;elastic modulus;loading;mechanical property;shrinkage;steel
摘要：
Steel-concrete composite structures are widely used in modern buildings and bridges for their great rigidity, light weight, and simple construction. However, the mechanical behaviors of steel-concrete composite structures degrade over time because of environmental corrosion and long-term load. The existing research on structural durability has often focused on concrete or steel structures. Few studies have been conducted on steel-concrete composite structures, especially on structures under the coupled impact of corrosion and load. To investigate the coupled impact of corrosion and load on the performance of steel-concrete composite structures, a long-term test of 200 days was carried out on eight connectors. The corrosion of the studs was accelerated by DC current, and the test connectors were submerged in a salt solution with a concentration of 5% NaCl. Deformations including the concrete strain and relative slippage between the concrete slab and the steel beam were measured in the long-term test. The experimental results showed that at the end of the long-term test, the deformations induced by shrinkage were about three times larger than those induced by creep for the steel-concrete composite structures. Notably, the stiffness of the connectors degraded substantially with the aggravation of the corrosion of the studs, whereas the concrete strain was only slightly affected by the studs' corrosion. The measured deformations were also obviously larger than those calculated by the current specifications. As a reference, a suitable formula for the long-term elastic modulus is proposed to enhance the applicability of specifications © 2018 American Society of Civil Engineers.
语种：
英文
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Experimental Study on the Long-Term Behaviour of RBPC T-Beams
作者：
Cao, Guohui* ;Zhang, Wang;Hu, Jiaxing;Zhang, Kai
期刊：
International Journal of Civil Engineering ,2018年16(8):887-895 ISSN：1735-0522
通讯作者：
Cao, Guohui
作者机构：
[Cao, Guohui; Zhang, Kai] Hunan City Univ, Coll Civil Engn, 518 Yingbin East RD, Yiyang 413000, Hunan, Peoples R China.;[Zhang, Wang] Changsha Univ Sci & Technol, Coll Civil Engn & Architecture, 960,2nd Sect,Wanjiali South RD, Changsha 410114, Hunan, Peoples R China.;[Hu, Jiaxing] Hunan Univ, Coll Civil Engn, Lushan South RD, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Cao, Guohui] H;Hunan City Univ, Coll Civil Engn, 518 Yingbin East RD, Yiyang 413000, Hunan, Peoples R China.
关键词：
Concrete beams and girders;Deflection (structures);Prestressed beams and girders;Prestressed concrete;Prestressing;Shrinkage;Bonded materials;Deflection;Long-term behavior;Long-term deflections;Pre-stressed;Prestress loss;Regular patterns;Retard-bonded;T beams;Uniform loads;Creep
摘要：
This study compares the mechanical properties of the retard-bonded and conventionally bonded prestressed concrete (RBPC and BPC, respectively) under uniform loads. Results show that the prestressed strands and concrete of the RBPC T-beams are firmly bonded with harden of retard-bonded materials, thereby exhibiting the same mechanical properties as that of the BPC beams. The growth rate of the long-term deflections of the RBPC T-beam is slightly lower than that of the BPC T-beam. Given the effect of concrete shrinkage, creep and time variation of prestress loss, the regular patterns of deflection growth of the RBPC T-beam mid-spans are analysed based on the age-adjusted effective modulus method, method of equivalent prestress load and calculation model of prestress loss. Accordingly, the long-term deflection development curves of the RBPC T-beam mid-spans under self-weight, prestressing force and external loads are obtained. Calculation results are in good agreement with the test results. This method has immense applicability for the computation of the RBPC T-beams, and can be used to estimate the long-term deflection growth of regular patterns of the RBPC components. © 2017, Iran University of Science and Technology.
语种：
英文
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Long-term deflection test and theoretical analysis on cracked prestressed concrete box beams
作者：
Cao, Guo Hui* ;Zhang, Sheng;Zhang, Wang;Peng, Xi Rong
期刊：
KSCE Journal of Civil Engineering ,2018年22(2):688-695 ISSN：1226-7988
通讯作者：
Cao, Guo Hui
作者机构：
[Cao, Guo Hui; Peng, Xi Rong] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Hunan, Peoples R China.;[Zhang, Sheng; Zhang, Wang] Changsha Univ Sci & Technol, Coll Civil Engn & Architecture, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Cao, Guo Hui] H;Hunan City Univ, Coll Civil Engn, Yiyang 413000, Hunan, Peoples R China.
关键词：
simply supported box beam;long-term deflection;theoretical calculation;prestressed concrete;effective modulus method
摘要：
A long-term deflection test is performed for 470 days on two simply supported prestressed concrete box beams under sustained uniform load. The deflection growth rules of the box beams under both cracked and uncracked states are studied. The measured longterm deflection of the cracked beam is 18.4% larger than that of the uncracked beam, whereas the deflection growth coefficient of the cracked beam is 65.3% that of the uncracked beam. The larger long-term deflection of the cracked beam is mainly attributed to the huge value of the instantaneous deflection caused by the crack. Then, the cracks lead to the release of concrete stress, thereby reducing the creep effect. For the uncracked beam, the influences of concrete shrinkage, creep, and prestress loss on the long-term mechanical behavior of components are considered, and then deflection is predicted using the blended method based on the age-adjusted modulus method, the prestressed equivalent load method, and the calculation method for prestress loss. Results show that the theoretical and measured values are in good agreement. For the cracked beam, the crack influence coefficient is introduced to revise its effective elastic modulus by considering the influence of cracks on the long-term deflection of the cracked beam. Then, a formula for calculating the long-term deflection of cracked beams that considers stiffness reduction for instantaneous deflection correction is proposed. The formula exhibits high precision in calculating and analyzing the long-term deflection of the cracked beam. The deviation between the calculated and measured values is within 10%.
语种：
英文
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预应力钢-混凝土组合连续箱梁挠度分析
作者：
莫东山;曹国辉
期刊：
湖南城市学院学报(自然科学版) ,2018年27(5):7-11 ISSN：1672-7304
作者机构：
湘潭大学 土木工程与力学学院,湖南 湘潭,411100;[曹国辉; 莫东山] 湘潭大学
关键词：
预应力;钢-混凝土组合连续箱梁;刚度;开裂;挠度
摘要：
对3片钢-混凝土组合连续箱梁跨中挠度进行了试验研究与理论分析,考虑开裂和滑移效应的影响,采用换算截面法和虚功原理建立了组合梁挠度计算表达式,推导了混凝土支座负弯矩区开裂长度计算表达式.研究结果表明,挠度理论计算值均与试验值吻合较好,预应力施加可提高混凝土开裂荷载,但对挠度的影响不显著.
语种：
中文
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应用型地方高校土木工程虚拟仿真实验教学中心建设探索
作者：
蒋建清;曹国辉;陈东海;贺冉;何敏
期刊：
实验室研究与探索 ,2018年37(2):144-149 ISSN：1006-7167
作者机构：
湖南城市学院土木工程学院,湖南益阳,413000;[贺冉; 何敏; 陈东海; 曹国辉; 蒋建清] 湖南城市学院
关键词：
虚拟仿真实验;实验教学中心;土木工程;应用型;地方高校
摘要：
虚拟仿真实验技术应用于土木工程教学领域,可以解决传统土木工程实践教学与现代应用型人才培养之间的一些突出矛盾。结合地方高校对接产业发展和行业需求、面向工程实践培养应用型人才的现实需要,论述了应用型地方高校土木工程虚拟仿真实验教学中心的建设理念和土木工程虚拟仿真实验教学体系的构建思路,分析了土木工程虚拟仿真实验教学资源平台的功能和组构模式。实践表明,为提升学生的创新意识、工程实践能力、信息化应用能力、综合素质和自主实验的学习兴趣,提高土木工程应用型人才培养成效,地方高校应校企合作开发"层次化、模块化、体系化"的土木工程虚拟仿真实验教学资源,建立"高度仿真、虚实结合、开放共享"的应用型虚拟仿真实验系统,积极开展土木工程虚拟仿真实验教学。
语种：
中文
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强化工程实践能力培养的土木工程实验教学模式探索
作者：
蒋建清;曹国辉;贺冉;陈东海;何敏
期刊：
教育现代化 ,2017年4(39):1-3 ISSN：2095-8420
作者机构：
湖南城市学院 土木工程学院,湖南 益阳,413000;[贺冉; 何敏; 陈东海; 曹国辉; 蒋建清] 湖南城市学院
关键词：
土木工程;实验教学;工程实践能力;应用技术型;地方高校
摘要：
土木工程实验教学是应用技术型地方高校培养学生工程实践能力和创新应用意识的重要途径.本文从应用技术地方高校实际出发,结合实验室建设的现实情况,探讨强化工程实践能力的土木工程实验教学模式,为培养学生的工程实践能力探索多样化的途径,使土建类学生的实验学习兴趣、积极性和主动性得到明显提高,工程实践能力、创新能力和综合素质不断提升,可供同类院校土木工程应用型人才培养参考.
语种：
中文
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Analysis of reinforcement influence on concrete creep
作者：
曹国辉;阳亮;张锴;彭细荣
期刊：
中南大学学报(自然科学版) ,2017年48(2):506-511 ISSN：1672-7207
通讯作者：
Zhang, Kai(349639499@qq.com)
作者机构：
[曹国辉; 张锴; 彭细荣] College of Civil Engineering, Hunan City University, Yiyang;413000, China;[阳亮] College of Civil Engineering, Hunan University, Changsha;410082, China;[曹国辉; 张锴; 彭细荣] 413000, China
通讯机构：
College of Civil Engineering, Hunan City University, Yiyang, China
关键词：
钢筋混凝土柱;徐变;钢筋修正系数;基于龄期调整的有效模量法;配筋率
摘要：
基于龄期调整的有效模量法和内力重分布机理,引入钢筋修正系数预测钢筋混凝土的徐变并且推导出相应的计算公式。通过对相关数据进行拟合分析,验证钢筋修正系数的有效性和实用性。在此基础上,提出基于现行公路桥涵设计规范徐变模型的配筋混凝土徐变计算公式,并分析老化系数、配筋率、加载龄期等参数对徐变的影响。研究结果表明:配筋对混凝土徐变具有抑制作用;当配筋率很小时,配筋对混凝土的相对抑制作用最强,随着配筋率增大,相对抑制作用逐渐降低;加载龄期和配筋对混凝土徐变的影响有叠加作用,并且这种叠加作用不只是简单的线性叠加。
语种：
中文
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Flexural failure experiment on cracked PC simply supported box girders
作者：
Cao Guo-hui* ;Zhang Wang;Peng Xi-rong;Zhang Sheng
期刊：
中南大学学报(英文版) ,2017年24(11):2685-2692 ISSN：2095-2899
通讯作者：
Cao Guo-hui
作者机构：
[Cao Guo-hui; Peng Xi-rong] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.;[Zhang Wang; Zhang Sheng] Changsha Univ Sci & Technol, Coll Civil Engn & Architecture, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Cao Guo-hui] H;Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.
关键词：
PC box girders;long-term load experiment;flexural behaviors;cracks;static performance
摘要：
Long-term load and flexural failure experiments are carried out on two prestressed concrete (PC) simply supported box girders. In the long-term load experiment, girder-1 (G1) is in an elastic state, while girder-2 (G2) is in a cracking state. To investigate the influence of cracking on the flexural behaviors of PC simply supported box beams, the experiment results are analyzed from many aspects, such as load–deflection, load–strain, and failure mode. Experiment results show the following: 1) the shrinkage and creep of concrete have considerable influences on the long-term deflection and strain of the two girders; 2) in the flexural failure experiment, the cracks and ultimate loads of the two girders are close. The rigidity degeneration of G2 is significantly faster than that of G1, and thus G2 shows nonlinear characteristics earlier; 3) to prove the validity and rationality of the current code, the cracking load and ultimate load of the two girders are calculated according to the current code. © 2017, Central South University Press and Springer-Verlag GmbH Germany, part of Springer Nature.
语种：
英文
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Coupling model for calculating prestress loss caused by relaxation loss, shrinkage, and creep of concrete
作者：
Cao Guo-hui* ;Hu Jia-xing;Zhang Kai
期刊：
中南大学学报(英文版) ,2016年23(2):470-478 ISSN：2095-2899
通讯作者：
Cao Guo-hui
作者机构：
[Cao Guo-hui; Zhang Kai] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.;[Hu Jia-xing] Hunan Univ, Coll Civil Engn, Changsha 410082, Peoples R China.
通讯机构：
[Cao Guo-hui] H;Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.
关键词：
prestress;relaxation loss;shrinkage and creep;theoretical analysis;calculation model
摘要：
The calculation model for the relaxation loss of concrete mentioned in the Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts (JTG D62—2004) was modified according to experimental data. Time-varying relaxation loss was considered in the new model. Moreover, prestressed reinforcement with varying lengths (caused by the shrinkage and creep of concrete) might influence the final values and the time-varying function of the forecast relaxation loss. Hence, the effects of concrete shrinkage and creep were considered when calculating prestress loss, which reflected the coupling relation between these effects and relaxation loss in concrete. Hence, the forecast relaxation loss of prestressed reinforcement under the effects of different initial stress levels at any time point can be calculated using the modified model. To simplify the calculation, the integral expression of the model can be changed into an algebraic equation. The accuracy of the result is related to the division of the periods within the ending time of deriving the final value of the relaxation loss of prestressed reinforcement. When the time division is reasonable, result accuracy is high. The modified model works excellently according to the comparison of the test results. The calculation result of the modified model mainly reflects the prestress loss values of prestressed reinforcement at each time point, which confirms that adopting the finding in practical applications is reasonable. © 2016, Central South University Press and Springer-Verlag Berlin Heidelberg.
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英文
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