钢板混凝土组合剪力墙施工早期的温度裂缝控制研究

发布时间：2018-04-18 18:24

本文选题：钢板混凝土组合剪力墙 + 高性能混凝土　；参考：《重庆大学》2014年硕士论文

【摘要】：钢板混凝土组合剪力墙结构因强度高、抗侧移刚度大、延性好等特点常用于超高层建筑、重要的大跨度建筑中。钢板混凝土组合剪力墙结构为了满足高强度、超高泵送等的要求，常选用高流动性、自密实的高性能混凝土。然而，高性能混凝土的水泥用量大，水化热多，施工早期受温度影响的收缩变形明显，在钢板、栓钉的约束下其内部容易形成较大的应力而开裂，最终影响耐久性。所以，为了减轻开裂程度，有必要研究钢板混凝土组合剪力墙施工早期温度裂缝的控制措施，以便为实际工程的设计、施工提供参考。作为温度的内热源，水化热本身会随时间变化，浇筑后混凝土以热对流的方式向空气散热且内外散热的速度不均，引起温度梯度，进而产生温差内应力。因此，钢板混凝土组合剪力墙在施工早期因水化热引起的温度场以及由此引起的应力场是一个复杂的空间、时间耦合的物理问题，相关的分析参数难以确定。所以，在模拟分析水化热对混凝土温度场的影响时常假定混凝土是一种各向同性材料。计算机的快速发展促进了数值分析技术的改进，并涌现出许多大型通用有限元软件，为模拟钢板混凝土组合剪力墙在施工早期的温度裂缝提供了有效的分析工具。本文利用ABAQUS软件进行钢板混凝土组合剪力墙施工早期的温度裂缝分析。分析时，先建立三个模型来研究混凝土水化热与温度的关系，它们分别是单层钢板混凝土组合剪力墙模型，循环冷却水作用下的钢板混凝土组合剪力墙模型，逐层浇筑的三层钢板混凝土组合剪力墙模型。随后根据水化热引起的温度变化规律，模拟钢板混凝土组合剪力墙的温度应力和温度裂缝，最后得出如下结论： ①钢板混凝土组合剪力墙施工早期在水化热和外界环境的影响下，先升温很快，然后缓慢降温。同时，整个过程中内外混凝土存有温度梯度，内部温度高，外部温度低。随着施工期延长，混凝土的内外温度趋于稳定并与环境温度相同。 ②钢板混凝土组合剪力墙中设置循环冷却管后可以降低水化热引起的内部最高温度，减小高温区范围，并使温度分布更均匀。因此，施工时在钢板混凝土组合剪力墙内部设置循环水冷却管能够对施工早期的温度裂缝进行有效地控制。 ③钢板混凝土组合剪力墙逐层浇筑时上下层混凝土会相互影响，上层混凝土的水化热会使下层混凝土温度回升，这将会导致上下层混凝土的交接薄弱层开裂。因此，在浇筑上层混凝土时应对下层混凝土的上部进行加强处理。 ④钢板混凝土组合剪力墙中栓钉和钢板对混凝土施工早期的温度收缩变形具有较强的约束作用，同时栓钉具有诱导开裂的不利作用。 ⑤一定范围内，钢板混凝土组合剪力墙栓钉的间距越小，混凝土的温度应力分布越均匀，且出现的裂缝越少。所以，在满足施工条件下把栓钉的间距设计越小对其温度裂缝的控制越有利。
[Abstract]:Steel concrete composite shear wall structure with high strength, lateral stiffness, good ductility and other features commonly used in high-rise building, the construction of large span steel concrete composite shear wall structure. In order to meet the high strength, high pumping and other requirements, often with high mobility, self compacting high performance concrete however, the amount of cement high performance concrete, hydration heat, the early shrinkage is affected by temperature deformation obviously, in steel studs under the constraints of its internal easy to form larger stress cracking, ultimately affect the durability. So, in order to reduce the degree of cracking control measures, it is necessary to study the concrete composite plate shear wall construction early temperature crack, in order for the actual engineering design, construction to provide the reference.
As the internal heat source temperature, hydration heat itself will change with time, after pouring concrete to convection to heat and air inside and outside the cooling speed is not uniform, caused by temperature gradient, resulting in temperature stress. Therefore, the temperature field of steel plate concrete composite shear wall construction in the early stage because of the hydration heat caused therefrom the stress field is a complex space time coupling physical problems, analysis of related parameters are difficult to determine. So, the simulation analysis of the influence of hydration heat on the temperature field of concrete often assumes that concrete is a kind of isotropic material.
The rapid development of computer technology promotes the improvement of numerical analysis, and the emergence of many large-scale general finite element software to simulate the steel-concrete composite shear wall in the construction of early temperature cracks provide an effective analysis tool. In this paper, steel concrete composite shear wall analysis of concrete temperature crack in the construction of early using ABAQUS software. The analysis. The first three models were established to study the hydration heat of concrete and temperature, they are single steel concrete composite shear wall model, circular steel plate concrete composite shear wall model of cooling water under the action of three layers of steel concrete composite shear wall model of casting layer by layer. Then according to the variation of temperature caused by hydration heat and the simulation of sprcw temperature stress and temperature crack, the final conclusion is as follows:
The steel-concrete composite shear wall construction in the early stage of hydration heat and the external environment under the influence of the first heat up quickly, and then slow down. At the same time, the whole process inside and outside the concrete has the temperature gradient, high internal temperature, external temperature is low. With the construction period, the concrete internal and external temperature stable and identical with the ambient temperature.
The steel-concrete composite shear wall arranged in the cooling tube can reduce the maximum internal temperature caused by hydration heat, reduce the high temperature area, and makes the temperature distribution more uniform. Therefore, in the construction of internal steel plate concrete composite shear wall tube can effectively control the temperature crack of the early construction of the circulating cooling water.
The steel-concrete composite shear wall with concrete pouring on the lower layer will influence each other, the hydration heat of concrete will make the upper lower concrete temperature rise, it will cause the lower concrete transition weak layer cracking. Therefore, in the pouring of concrete to the upper upper lower concrete for strengthening treatment.
The steel stud and steel concrete composite shear wall has a strong restriction on the early shrinkage of concrete construction temperature deformation, and has the adverse effect of stud induced cracking.
In a certain range, spacing of steel-concrete composite shear wall studs is smaller, the concrete temperature stress distribution is more uniform, and the crack appeared less. So, in the conditions to meet the construction design of the studs spacing is to control the temperature crack more favorable.

【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU765

【参考文献】