冻融循环对外墙保温板与结构层粘结性能的影响

发布时间：2018-04-15 14:28

本文选题：外墙外保温 + 冻融循环　；参考：《西安工业大学》2017年硕士论文

【摘要】：众所周知,建筑外墙是建筑物保温隔热的重要构件,提高建筑物外墙保温隔热能力,能大大延长建筑物的使用寿命。外墙外保温技术作为建筑节能墙体研究的重要组成部分,在工程上得到了广泛的应用。然而,外墙外保温技术在使用过程中出现的质量问题也越来越多,尤其是粘结性差一直是影响外墙保温系统稳定性的首要问题。本文主要针对季节性冻融引起的外墙外保温系统的开裂、脱落现象,选取挤塑板、聚氨酯、硅质聚苯板三种保温材料以及其对应的粘结砂浆、锚栓等配套材料,进行了试验和理论研究,主要完成了以下工作:1)研究冻融循坏次数对保温材料几何尺寸变化率的影响。通过研究冻融循坏作用对保温材料几何尺寸变化率的影响,为避免外墙面起拱变形,产生裂缝、造成墙面开裂等现象提供参考依据。通过在冻融循环次数后对挤塑板、聚氨酯、硅质聚苯板三种保温材料几何尺寸变化进行测试研究,测得三种材料在不同冻融次数、不同方向下尺寸变化率的试验结果,得出挤塑板的尺寸变化最为明显,变化值也最大,尺寸变化整体在1.5%左右,厚度方向个别达到了 2%;硅质聚苯板尺寸变化最小、最为稳定,其尺寸变化不超过1%。2)研究冻融循环作用下,外墙外保温系统中保温板与结构层的粘结层在轴向受拉情况下的破坏类型及破坏时应力分界点,得出挤塑板和硬泡聚氨酯与结构层的破坏面主要是结构层与保温板之间的粘结面破坏在,硅质聚苯板与外墙基层的的拉伸破坏主要保温板自身的破坏。通过抗拉试验分析外墙外保温系统中挤塑板、聚氨酯、硅质聚苯板等保温材料与结构层之间的抗拉力及抗拉粘结强度与冻融循环次数之间的关系,得出冻融循环30次后三种保温系统的抗拉强度大小关系为硅质聚苯板硬泡聚氨酯挤塑板,其中挤塑板的部分试样在冻融30次后,与结构层直接脱落,出现拉伸力为0的情况。此外通过实验数据分析拉伸强度损失率与冻融循环次数的定量关系,推导出拉伸粘结强度逐步退化的数学公式,为提高三种外墙保温材料在实际工程的安全性应用提供参考。3)研究冻融循环作用下,竖向剪力对三种外墙保温材料与结构层粘结性能的影响。通过抗剪试验分析挤塑板、聚氨酯、硅质聚苯板等保温材料与结构层之间的剪切粘结强度与冻融循环次数之间的关系。通过试验结果,得出冻融循环30次后三种保温系统的剪切强度大小为保持硅质聚苯板硬泡聚氨酯挤塑板,其中硅质聚苯板外墙保温体系的抗剪强度始终保持在0.06 MPa左右,没有随冻融次数增加有较大的变化,而其他两种保温体系抗剪强度低于0.03 MPa,下降幅度较大。此外通过实验数据并分析剪切强度损失率与冻融循环次数的定量关系,推导出剪切粘结强度逐步退化的数学公式,为提高三种外墙保温材料在实际工程的安全性应用提供参考。
[Abstract]:As we all know, the building exterior wall is an important component of building insulation and insulation. Improving the ability of building exterior wall insulation can greatly prolong the service life of buildings.As an important part of building energy-saving wall, exterior wall insulation technology has been widely used in engineering.However, there are more and more quality problems in the use of external insulation technology, especially the poor adhesion is always the primary problem affecting the stability of external wall insulation system.Aiming at the cracking and shedding of exterior wall insulation system caused by seasonal freezing and thawing, this paper selects three kinds of insulation materials, such as extruded plastic board, polyurethane, silicon polystyrene board, and corresponding supporting materials such as bonded mortar, anchor bolt, etc.Experiments and theoretical studies have been carried out, and the following work has been done: 1) to study the influence of freeze-thaw failure times on the change rate of geometric dimensions of insulating materials.By studying the effect of freeze-thaw failure on the change rate of geometric dimension of insulating material, the paper provides a reference for avoiding arched deformation, cracks and other phenomena of wall surface.After freeze-thaw cycles, the geometric size changes of three kinds of insulating materials, such as extruded plasticizer, polyurethane and siliceous polystyrene board, were measured, and the results of the three kinds of materials under different freezing and thawing times and in different directions were obtained.The results show that the dimension change of extruded plastic board is the most obvious, the change value is the biggest, the dimension change is about 1.5% as a whole, the thickness direction has reached to 2% individually, the silicon polystyrene board has the smallest change in size, the most stable,Under the action of freeze-thaw cycle, the failure type and stress boundary point of the bonding layer between the thermal insulation board and the structure layer in the external wall insulation system under axial tension are studied.It is concluded that the failure surface of extruded plastic board and hard foam polyurethane and structure layer is mainly the bond surface between structure layer and insulation board, and the tensile damage of silicone polystyrene board and external wall base is main damage of insulation board itself.The relationship between tensile strength, tensile bond strength and freeze-thaw cycle times of extruded plastic board, polyurethane, silicon polystyrene board and structure layer in external insulation system of external wall was analyzed by tensile test.It is concluded that the tensile strength of the three kinds of insulation system after 30 cycles of freeze-thaw cycle is hard foam polyurethane extruded board of siliceous polystyrene board. After 30 times of freeze-thaw, some samples of extrusion board fall off directly from the structure layer, and the tensile force is 0.In addition, the quantitative relationship between the tensile strength loss rate and the number of freeze-thaw cycles is analyzed through the experimental data, and the mathematical formula for the progressive degradation of tensile bond strength is derived.In order to improve the safety application of three kinds of exterior wall insulation materials in practical engineering, reference. 3) to study the effect of vertical shear force on the bond properties of three kinds of external wall insulation materials and structure layer under freeze-thaw cycle.The relationship between shear bond strength and freeze-thaw cycle times of heat preservation materials such as extruded plasticizer, polyurethane, siliceous polystyrene board and structure layer was analyzed by shear test.The results show that the shear strength of the three thermal insulation systems after 30 cycles of freeze-thaw cycle is to keep the silicone polystyrene board rigid foam polyurethane extrusion board, and the shear strength of the external wall insulation system of silicon polystyrene board is kept at about 0.06 MPa, and the shear strength of the insulation system is about 0.06 MPa, and the shear strength of the external wall insulation system is about 0.06 MPa.The shear strength of the other two thermal insulation systems was less than 0.03 MPa and decreased greatly.In addition, based on the experimental data and the quantitative relationship between the shear strength loss rate and the number of freeze-thaw cycles, the mathematical formula of shear bond strength degradation is derived, which provides a reference for improving the safety application of three kinds of exterior wall insulation materials in practical engineering.
【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU111.41

【参考文献】