连续玻璃纤维筋水泥混凝土路面结构设计研究

Research on Structural Design of Continuous Glass Fiber Reinforced Cement Concrete Pavement Structure

针对连续玻璃纤维筋水泥混凝土路面(GFRP-CRCP)工程应用较少且设计研究方法较缺乏的问题,推导了解析梁的平衡微分方程,得到了钢筋和混凝土的位移和应力方程,建立了混凝土温缩和干缩作用下配筋设计指标的解析公式。依据GFRP-混凝土的黏结强度试验和高速公路工程试验路段算例,分析了GFRP-CRCP面层的位移、应力分布规律,并与钢筋-CRCP结构的计算结果进行了比较,获得了适用于GFRP结构设计的配筋指标上限值。用ABAQUS有限元软件建立了三维模型,辅助计算和验证了解析计算结果为有效可信。最后,筛选出了影响较大的因素,分析了GFRP直径和弹性模量对配筋设计指标的影响规律。主要结论有:(1)当GFRP和混凝土相对滑移量≤0.40mm时,满足线性滑移模型,其黏结刚度系数约为22.4MPa·mm^(-1);(2)在混凝土温缩和干缩作用下,GFRP的纵筋最大拉应力和混凝土最大拉应力比配置钢筋工况分别减小了56.4%和56.5%,裂缝宽度比配置钢筋工况增加了0.054mm;(3)建议算例结构的GFRP-CRCP横向裂缝间距上限取1.4m,裂缝宽度上限取0.80mm;(4)结构应力随着GFRP直径和弹性模量的增大而增大,裂缝宽度会随之减小。

Regarding the problem that the continuously reinforced concrete pavement using glass fiber reinforced polymer(GFRP-CRCP)is not widely used in practice and lacks studies of design method,the equilibrium differential equation of analytical beam is derived,the displacement and stress equations of reinforcement and concrete are obtained,and the analytical formula of reinforcement design indicators under the action of temperature shrinkage and dry shrinkage of concrete are established.Based on GFRP-concrete bond strength test and a testing road of highway project,the displacement and stress distribution of GFRP-CRCP surface layer are analyzed,and compared with the calculation results of steel rebar CRCP structure,the upper limit of reinforcement indicator that is suitable for GFRP structure design is obtained.The ABAQUS finite element software is used to establish a three dimensional model,and the analytical results are verified to be valid and reliable.Finally,the most influential factors are screened out and the influence of GFRP diameter and elastic modulus on reinforcement design indicators is analyzed.The main conclusions are as follows:(1)when the relative slip of GFRP and concrete is less than or equal to 0.40 mm,it meets the requirement of linear slip model,and the bond stiffness coefficient of GFRP and concrete is about 22.4 MPa·mm^(-1);(2)under the effect of concrete temperature shrinkage and dry shrinkage,the maximum tensile stress of GFRP longitudinal bars and the maximum tensile stress of concrete are reduced by 56.4%and 56.5%respectively,and the crack width is increased by 0.054 mm compared with that of steel bars;(3)it is suggested that the upper limit of transverse crack spacing of GFRP-CRCP structure is 1.4 m and the upper limit of crack width is 0.80 mm;and(4)the structural stress increases with the increase of GFRP diameter and elastic modulus,and the crack width decreases accordingly.