钢筋混凝土路面板早龄期力学行为特性研究

发布时间：2018-03-22 00:36

本文选题：钢筋混凝士路面　切入点：早龄期　出处：《福州大学》2014年硕士论文　论文类型：学位论文

【摘要】：本文重点从考虑早龄期影响的分析角度,基于三维数值分析、足尺板试验方法,重点对早龄期施工阶段钢筋混凝土路面(JRCP)的力学行为特性,早龄期-服役期联动作用下钢筋混凝土板的受荷力学特性,以及普通混凝土路面与钢筋混凝土路面的早龄期、服役期性能差异开展了研究。研究结论如下：路面板早龄期翘曲变形在前60小时,由于混凝土模量较低,面板变形以板角翘曲变形为主,进一步随着龄期增长,板1/4位置、板中位置依次开始参与面板整体变形,并出现脱空现象。钢筋应力与混凝土应力变化趋势相同,钢筋应力显著大于混凝土应力,板顶与板底钢筋应力出现波动循环现象,但拉压变换较混凝土相对稳定,板中间部位处钢筋应力波动幅度较大,绝对值相比其它位置大。混凝土材料参数和界面参数对钢筋混凝土板的早龄期行为影响,相比钢筋设计参数影响显著。切向刚度系数和法向刚度系数对板角竖向位移影响显著；热膨胀系数、路面板厚度、路面板长度、切向刚度系数及法向刚度系数对板中混凝土应力影响显著；混凝土热膨胀系数、路面板厚度对钢筋应力影响显著。季节气候条件和施工时刻对面板早龄期力学行为的影响,主要体现在面板施工终凝后产生的固化温度,以及各季节每日温差的波动所形成的应力历史作用。在夏季以及春季的一些时间点上,每日温差较大,在早上7点施工的面板极易形成较大的固化温度,这对面板的早龄期性能产生较大的影响。JPCP与JRCP在早龄期性状上近似,而与CRCP有显著不同。JPCP、JRCP均会产生较大的翘曲变形。CRCP连续配筋路面平整度较好,但混凝土应力较大,且持续处于拉应力状态,极易发生开裂。钢筋混凝土路面均会比普通水泥混凝土路面的混凝土应力小,但钢筋主要改善邻近混凝土应力,在相同配筋率下,采用双层钢筋网的路面结构形式,可同时降低路面板顶及板底处混凝土应力。同等条件下,JRCP早期固化翘曲比JPCP大,早龄期形成的翘曲显著影响路面的服役性能,随着板角翘曲位移增大,钢筋在路面板中作用减小,尤为不利。足尺试验观测发现,基本规律与数值分析结论接近,早龄期阶段板块特定部位的位移和应力状态除受到环境温度作用外,还受到凝固固化温度作用、水化反应、重力、徐变以及板块变形形状和内部应力应变协调的综合作用,性状表现与成熟混凝土路面有很大不同。
[Abstract]:From the point of view of considering the influence of early age, based on three-dimensional numerical analysis and full-scale plate test method, this paper focuses on the mechanical behavior of reinforced concrete pavement in early age construction stage. The mechanical properties of reinforced concrete slabs under the combined action of early age and service, and the early age of ordinary concrete pavement and reinforced concrete pavement, The difference of service performance was studied. The results are as follows: the early age warpage deformation of the pavement slab is 60 hours. Because of the low modulus of concrete, the main deformation of the slab is the angular warping deformation of the slab. Further, with the increase of the age, the slab has a quarter of a position. The stress of steel bar is the same as that of concrete, the stress of steel bar is obviously larger than that of concrete, and the stress of steel bar on top of slab and bottom of slab is fluctuating and circulating. However, the tension and compression transformation is more stable than that of concrete, the stress fluctuation in the middle part of the slab is larger, and the absolute value is larger than that in other places. The influence of concrete material parameters and interface parameters on the early age behavior of reinforced concrete slabs is obtained. Compared with the design parameters of steel bar, the influence of tangential stiffness coefficient and normal stiffness coefficient on the vertical displacement of slab angle is significant, the thermal expansion coefficient, the thickness of road panel, the length of road slab, The effects of tangential stiffness coefficient and normal stiffness coefficient on concrete stress in slab, thermal expansion coefficient of concrete and thickness of pavement slab on stress of steel bar are significant, and the influence of seasonal climate conditions and construction time on early age mechanical behavior of slab is also discussed. Mainly reflected in the solidification temperature after the final solidification of the face slab construction, and the stress historical effect formed by the fluctuation of the daily temperature difference in each season. At some time points in summer and spring, the daily temperature difference is large. It is easy to form a larger curing temperature in the face panel constructed at 7 am, which has a great influence on the early age performance of the panel. JPCP and JRCP are similar to each other in the early age behavior. However, there is a significant difference between CRCP and CRCP, which can produce large warping deformation. CRCP-continuous reinforced pavement has better smoothness, but the concrete stress is larger, and the concrete is in the state of tensile stress continuously. It is easy to crack. The concrete stress of reinforced concrete pavement is smaller than that of ordinary cement concrete pavement, but the reinforcement mainly improves the stress of adjacent concrete. At the same time, the concrete stress at the top of the pavement slab and the bottom of the slab can be reduced. Under the same conditions, the early curing warpage of JPCP is larger than that of JPCP, and the early age warpage significantly affects the service performance of the pavement, and with the increase of the slab-angle warpage displacement, It is found that the basic law is close to the conclusion of numerical analysis, and the displacement and stress state of certain parts of the plate in early age stage are not only affected by ambient temperature, but also by the effect of environmental temperature. It is also affected by the combination of solidification temperature hydration reaction gravity creep plate deformation shape and internal stress and strain. The behavior is very different from that of mature concrete pavement.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.216

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