摘要
提出了一种以大粒径球状SAP为造孔剂的混凝土作为隧道缓冲层的方法,并制备了试样,研究了其物理力学性能以验证其作为缓冲材料的可行性以及相对于同等其他缓冲材料的优越性。结果表明:使用0.2mol/L的碳酸钠溶液预吸水饱和的SAP在水泥浆中失水相对缓慢,有利于混凝土在后期强化过程中的水化作用。SAP混凝土的渗透系数为10^(-7)cm/s数量级,比同密度级别的泡沫混凝土略小。SAP混凝土缓冲材料表现为明显的脆性,而其他缓冲材料如泡沫混凝土、橡胶混凝土等大多为延塑性,利用SAP混凝土材料脆性的特征,将其应用于粘滑错动的隧道中,其瞬时丧失抗压能力的特性为其提供了极大的让压性能,从而保护衬砌不受破坏。研究还发现,在一定的围压条件下,SAP混凝土的峰值强度和残余强度均有显著提升,过高的峰值和残余强度不利于SAP混凝土发挥其优良的缓冲效果,因此应避免在高围压环境下使用SAP混凝土缓冲材料。
A method of making the tunnel buffer layer was proposed by using large diameter spherical SAP concrete as he pore forming agent,the relevant samples were prepared,the physical and mechanical properties were studied to verify its feasibility as a buffer material and its advantages over other equivalent buffer materials.The results show that,using 0.2 mol/L sodium carbonate solution to pre absorb saturated SAP loses water in cement slurry relatively slowly,which is beneficial to the hydration of concrete to consolidate its later strength.The permeability coefficient of SAP concrete is 10^(-7)cm/s,which is not much different from that of foam concrete with the same density.SAP concrete buffer materials are obviously brittle,while other buffer materials are mostly ductile such as foam concrete,rubber concrete,etc.Based on the brittleness of SAP concrete material,it is applied to the stuck-slip fault tunnel,and its instantaneous loss of compression capacity provides it with great yield capacity,thus protecting the lining from damage.Under a certain confining pressure,the peak strength and residual strength of SAP concrete are significantly increased,while the peak strength and residual strength are too high,which are not conducive to the good buffering effect of SAP concrete.Therefore,in practical engineering,SAP concrete buffer materials should be avoided in a high confining pressure state as much as possible.
作者
曹俊
崔臻
梅贤丞
武哲书
张翔宇
张佳威
CAO Jun;CUI Zhen;MEI Xian-cheng;WU Zhe-shu;ZHANG Xiang-yu;ZHANG Jia-wei(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics Chinese Academy of Sciences,Wuhan 430071,China;School of Engineering Science,University of ChineseAcademy of Sciences,Beijing 100049,China;China Railway Siyuan Survey and Design Group Co Ltd,Wuhan 430063,China)
出处
《武汉理工大学学报》
CAS
2023年第12期74-83,共10页
Journal of Wuhan University of Technology
基金
国家自然科学基金(52079133)
水利部重大科技项目(SKS-2022103)
云南省重大科技专项计划(202102AF080001)
水利部重点实验室项目(QTKS0034W23291)
关键词
SAP混凝土
缓冲材料
抗错断
隧道
SAP concrete
buffer material
anti-dislocation
tunnel
作者简介
曹俊(1999-),男,硕士生.E-mail:caojun21@mails.ucas.ac.cn;通讯作者:崔臻(1986-),男,博士,研究员.E-mail:zcui@whrsm.ac.cn
