摘要
针对传统液体无碱速凝剂稳定性差、易分层、与水泥适应性差等问题,自主研发了高性能液体无碱速凝剂。通过试验研究了速凝剂碱含量对混凝土力学性能的影响及环境温度对无碱速凝剂稳定性的影响,并测试了高性能液体无碱速凝剂与水泥的适应性。结果表明:无碱速凝剂对喷射混凝土抗压强度和弹性模量的发展影响较小,而有碱速凝剂影响较大;低温条件会缩短速凝剂的稳定期,速凝剂出现分层后无法通过机械搅拌恢复促凝效果;自主研发的高性能液体无碱速凝剂在20℃的常温条件下90 d龄期内基本无分层,在-10℃的低温条件下90 d龄期分层量小于5%,具有稳定性高、与水泥适应性好的特点。该速凝剂应用于实际工程后,喷射混凝土回弹率显著降低,早期和长期抗压强度显著提高,混凝土抗渗性好。
Aiming at the problems of poor stability,easy stratification and poor adaptability of cement of traditional liquid alkali-free accelerator,a high performance liquid alkali-free accelerator was independently developed.The influence of alkali content of accelerator on the mechanical properties of concrete and the influence of ambient temperature on the stability of alkali-free accelerator was studied through experiments,and the adaptability of high performance liquid alkali-free accelerator to cement was tested.The results show that alkali-free accelerator has little influence on the development of compressive strength and elastic modulus of shotcrete,but alkali accelerator has more influence.Low temperature can shorten the stable period of the accelerator,and the accelerator with precipitation or stratification cannot restore the coagulation promoting effect by mechanical stirring.The self-developed high performance liquid alkali-free accelerator basically has no stratification at room temperature of 20℃for 90 days,and the stratification at low temperature of-10℃for 90 days is less than 5%,which means it has the characteristics of high stability and good adaptability with cement.After the accelerator is applied to practical engineering,the rebound rate of shotcrete is significantly reduced,the early and long-term compressive strength is significantly improved,and the impermeability of concrete is good.
作者
王家赫
谢永江
仲新华
李享涛
渠亚男
WANG Jiahe;XIE Yongjiang;ZHONG Xinhua;LI Xiangtao;QU Yanan(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;State Key Laboratory for Track Technology of High-speed Railway,Beijing 100081,China)
出处
《铁道建筑》
北大核心
2021年第1期130-134,共5页
Railway Engineering
基金
国家自然科学基金(51908550)
中国铁路总公司科技研究开发计划(P2018G047)
中国工程院咨询研究项目(2019-ZD-19-E)
中国铁道科学研究院集团有限公司科研项目(2018YJ044)。
关键词
工程材料
无碱速凝剂
试验研究
混凝土
力学性能
稳定性
适应性
engineering materials
alkali-free accelerator
experimental study
concrete
mechanical property
stability
adaptability
