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超高性能混凝土(UHPC)由于水胶比较低、胶凝材料含量高，致使其在早期易产生收缩裂缝。采用氧化镁膨胀剂(MEA)可以缓解UHPC的早期自收缩，但关于不同养护温度对MEA-UHPC影响的研究却相对较少。研究了不同养护温度对MEA-UHPC体积稳定性和抗压强度的影响，采用X射线衍射(XRD)、扫描电镜-能谱仪(SEM-EDS)等手段分析了水泥石的早期水化产物。结果表明：合理设计热养护体系有利于提高水泥基材料的力学性能和体积稳定性，对于UHPC体系而言，设计的热养护静停时间宜为24 h;采取40℃的养护温度，保证了MEA-UHPC体系中MH晶体及C-S-H凝胶的含量，使得水泥石的收缩补偿和力学性能达到相对平衡；此外，适宜的养护温度促进了MEA-UHPC体系中生成更多细长针棒状的C-S-H,是使得水泥石具有优异力学性能的原因之一。
Abstract：Ultra-High Performance Concrete(UHPC) is prone to Shrinkage cracks in the early stages due to its low water-cement ratio and high content of cementitious materials. The use of MgO Expansive Agent(MEA) can alleviate the early autogenous shrinkage of UHPC, but there is relatively sparse research on the effect of different curing temperatures on MEA-UHPC. This paper investigated the effects of different curing temperatures on the volume stability and compressive strength of MEA-UHPC and analyzed the early hydration products of cement stone using X-ray diffraction(XRD) and scanning electron microscope-energy dispersive spectrometer(SEM-EDS).The results showed that the reasonable design of the thermal curing system is conducive to the more effective improvement of the mechanical properties and volume stability of the cementitious materials, for the UHPC system, the delay period for hot curing should be 24 h.A curing temperature of 40 ℃ ensures the content of MH crystals and C-S-H gel in the MEA-UHPC system, which makes the shrinkage compensation and mechanical properties of the cement stone reach a relative equilibrium. In addition, the appropriate maintenance temperature promotes the generation of more slender needle like C-S-H in the MEA-UHPC system, which is one of the reasons for the excellent mechanical properties of cement stone.
[1] 孙世国，鲁艳朋.超高性能混凝土国内外研究进展[J].科学技术与工程，2018,18(20):184-199.
[2] RICHARD P,CHEYREZY M.Composition of reactive powder concretes[J].Cement and Concrete Research,1995,25(7):1501-1511.
[3] 谭青山，刘东海.考虑新老混凝土界面特性的UHPC-RC箱型组合箱梁抗弯性能研究[J].湖南交通科技，2024,50(2):50-54,59.
[4] 张云升，张国荣，李司晨.超高性能水泥基复合材料早期自收缩特性研究[J].建筑材料学报，2014,17(1):19-23.
[5] 陈宝春，李聪，黄伟，等.超高性能混凝土收缩综述[J].交通运输工程学报，2018,18(1):13-28.
[6] ZHANG X Z,LIU Z C,WANG F Z.Autogenous shrinkage behavior of ultra-high performance concrete[J].Construction and Building Materials,2019,226:459-468.
[7] 卫煜，陈平，明阳，等.超细高活性矿物掺合料对UHPC水化和收缩性能的影响[J].硅酸盐通报，2022,41(2):461-468.
[8] 刘荣进，丁庆军，陈平.新型聚合物内养护材料对高强混凝土自收缩影响研究[J].功能材料，2013,44(24):3561-3565.
[9] 胡曙光，周宇飞，王发洲，等.高吸水性树脂颗粒对混凝土自收缩与强度的影响[J].华中科技大学学报(城市科学版),2008,25(1):1-4,16.
[10] 邓宗才，连怡红，赵连志.膨胀剂、减缩剂对超高性能混凝土自收缩性能的影响[J].北京工业大学学报，2021,47(1):61-69.
[11] LIU A M,FANG Z,HUANG Z Y,et al.Solving shrinkage problem of ultra-high-performance concrete by a combined use of expansive agent,super absorbent polymer,and shrinkage-reducing agent[J].Composites Part B:Engineering,2022,230:109503.
[12] WANG Y S,LEE H S,LIN R S,et al.Effect of silicate-modified calcium oxide-based expansive agent on engineering properties and self-healing of ultra-high-strength concrete[J].Journal of Building Engineering,2022,50:104230.
[13] 刘加平，张守治，田倩，等.氧化镁复合膨胀剂对高性能混凝土变形特性的影响[J].东南大学学报(自然科学版),2010,40(增刊2):150-154.
[14] MO L,DENG M,WANG A.Effects of MgO-based expansive additive on compensating the shrinkage of cement paste under non-wet curing conditions[J].Cement and Concrete Composites,2012,34(3):377-383.
[15] 别安涛.轻烧氧化镁对水泥性能的影响研究[D].重庆：重庆大学，2010.
[16] CUI Y,LI Y H,WANG Q.Engineering performance and expansion mechanism of MgO expansion agent in ultra-high performance concrete (UHPC)[J].Journal of Building Engineering,2023,68:106079.
[17] LI S K,MO L W,DENG M,et al.Mitigation on the autogenous shrinkage of ultra-high performance concrete via using MgO expansive agent[J].Construction and Building Materials,2021,312:125422.
[18] MO L W,FANG J W,HUANG B,et al.Combined effects of biochar and MgO expansive additive on the autogenous shrinkage,internal relative humidity and compressive strength of cement pastes[J].Construction and Building Materials,2019,229:116877.
[19] 杨东洋，曹鸿猷，黄京龙.MgO膨胀剂对超高性能混凝土收缩性能的影响[J].硅酸盐通报，2022,41(10):3420-3427.
[20] 李红，邓敏，莫立武.不同活性氧化镁膨胀剂对水泥浆体变形的影响[J].南京工业大学学报(自然科学版),2010,32(6):98-102.
[21] 于方，唐诗，邓春林，等.温度和湿度对氧化镁膨胀剂膨胀性能的影响[J].硅酸盐通报，2020,39(10):3221-3229.
[22] 中国建筑材料联合会.混凝土用氧化镁膨胀剂：CBMF19—2017[S].北京：中国建材工业出版社，2017.
[23] 曹丰泽，阎培渝.氧化镁膨胀剂的性能与作用机理[C]//第十届全国高强与高性能混凝土学术交流会.2016:55-65.
[24] 张占强，陈平，李顺凯，等.氧化镁膨胀剂对UHPC浆体早期孔结构演变的影响[J].硅酸盐通报，2023,42(3):871-877,916.
[25] ZHANG Z Q,LI S K,CHEN P,et al.Mitigating shrinkage in ultra-high performance concrete using MgO expansion agents with different activity levels[J].Frontiers in Materials,2022,9:1033467.
[26] 吴萌.石灰基低碳胶凝材料的设计制备与水化机理研究[D].南京：东南大学，2021.
[27] 李延波，邓敏，莫立武，等.约束条件下外掺MgO混凝土的强度与膨胀应力[J].建筑材料学报，2012,15(4):446-450.
[28] 张建峰，董芸，陈霞，等.养护温度对MgO微膨胀混凝土变形性能的影响[J].混凝土，2019(3):49-52.
[29] 朱兆荣，赵守全，韩侃，等.寒区高速公路路基填料冻胀特性的试验装置及方法[J].公路工程，2020,45(1):156-162.
[30] 董烨民，胡传林.不同养护制度下大掺量石灰石煅烧黏土UHPC早期水化及力学性能发展[J].硅酸盐通报，2022,41(6):1879-1887.
[31] ZHANG G,PENG G F,ZUO X Y,et al.Adding hydrated lime for improving microstructure and mechanical properties of mortar for ultra-high performance concrete[J].Cement and Concrete Research,2023,167:107130.
[32] AL-OSTA M A,AHMAD S,AL-MADANI M K,et al.Performance of bond strength between ultra-high-performance concrete and concrete substrates (concrete screed and self-compacted concrete):an experimental study[J].Journal of Building Engineering,2022,51:104291.
[33] 张占强，李顺凯，陈平，等.高活性氧化镁膨胀剂对UHPC性能的影响[J].功能材料，2023,54(4):4189-4195.
[34] LI Z H,XU Y D,ZHANG T S,et al.Effect of MgO calcination temperature on the reaction products and kinetics of MgO-SiO2-H2O system[J].Journal of the American Ceramic Society,2019,102(6):3269-3285.
[35] CHEN J H,LI T,LI X P,et al.Some new perspective on the reaction mechanism of MgO-SiO2-H2O system[J].International Journal of Applied Ceramic Technology,2016,13(6):1164-1172.
[36] NGUYEN-TUAN L,BECKER F,KLEINER F,et al.Quantitative study on growth and porosity of C-S-H structures:experiments and simulations[J].Cement and Concrete Research,2023,174:107294.
[37] SIMONI M,WOO C L,ZHAO H,et al.Reaction mechanisms,kinetics,and nanostructural evolution of magnesium silicate hydrate(M-S-H)gels[J].Cement and Concrete Research,2023,174:107295.
[38] 王亚洲.水化硅酸钙的合成及其对水泥基砂浆性能的影响[D].武汉：武汉理工大学，2018.
[39] 龙诚璧，黄文武，钟林东，等.蒸汽养护对高性能混凝土力学性能影响研究[J].公路工程，2023,48(6):169-172,196.
[40] 左云，何均贺，耀北坪，等.复配新型防渗材料对混凝土性能影响试验研究[J].公路工程，2023,48(3):143-147.
[41] 袁润章.胶凝材料学[M].2版.武汉：武汉工业大学出版社，1996.
[42] 魏婷，周盛江，邓最亮，等.水化硅酸钙的形貌调控及其在水泥水化中的作用[J].华东理工大学学报(自然科学版),2024,50(3):364-370.
[43] 陈东哲.蒸养复掺混凝土力学性能时变规律与徐变特性研究[D].武汉：武汉科技大学，2023.
基本信息:
DOI：10.19782/j.cnki.1674-0610.2025.02.025
中图分类号:TU528
引用信息:
[1]田爱玲,朱兆荣,杲斐等.养护温度对减缩型UHPC性能的影响特性研究[J].公路工程,2025,50(02):211-219.DOI:10.19782/j.cnki.1674-0610.2025.02.025.
基金信息:
甘肃省住房和城乡建设厅科技项目(JK 2023-52); 中国铁建股份有限公司科技研究计划资助项目(2020-C25)