高温、高湿、高盐环境对木结构用材性能的影响
发布时间：2018-08-04 11:06
【摘要】：在中国倡导低碳的大背景下，木结构建筑以及与之相关的木产业发展前景正在被越来越多的人看好。特别是沿海地区，例如海南，近几年海南房地产进入高速发展期，旅游资源开发也进行得如火如荼，对于木结构建筑的需求十分旺盛，然而当地“日照、台风、降雨”三强、“高温、高湿、高盐”三高的气候环境特点使得对木结构建筑用材耐候性能、抗风性能、耐腐性能等要求大大提高。中国是地域差异较明显的国家，各个地方气候条件相差甚大，在木结构建筑进行施工以及施工一段时间后会发现，结构材料以及外饰面材料会产生开裂、变色、强度降低等现象，影响木结构建筑结构的安全性。 本文主要研究高温高湿、高盐环境对木结构建筑用材性能的影响。通过模拟不同的温湿度环境以及不同浓度的盐溶液分别对规格材握钉力、定向刨花板剪切性能以及齿板承载性能进行试验分析。研究发现： 规格材握钉力表面和侧面握钉力约为端面握钉力的4.27倍。三面握钉力会受三高环境的影响，其中湿度和盐分对其影响较大，温度对规格材几乎没有影响。随着湿度和盐分越大，规格材三面握钉力会逐渐减少，且各盐度梯度间差异显著。随着高温高湿处理周期的增加，规格材握钉力逐渐减小，随着盐分处理周期的增加，规格材握钉力先增大后减少，盐溶液浓度每增加0.5%，各侧握钉力下降了约为1%，在变化过程中均有一定的规律性。各侧握钉力随高温高湿处理周期变化的函数关系式：表面握钉力为y=-2.5317x+42.435；侧面握钉力为y=-2.6143x+43.589；端面握钉力为y=-0.7648x+15.716。上述式中x代表处理的周期数，y代表此时的握钉力大小。 高温高湿高盐环境对木结构钉连接抗剪性能的影响：湿度和盐分对其影响较大，温度对其几乎没有影响。随着盐浓度和温湿度的上升，单剪试件在承载过程中弹性形变阶段缩短，塑性形变阶段延长，使其屈服荷载较小；随着试件处理时间的延长，，各强度指标大体呈现下降的趋势，中途会有微弱的上升。其中在高温高湿处理中当处理周期达到48周期时，会达到极限荷载设计值。并能得出相应的回归曲线。 高温高湿高盐环境对木结构齿板抗拉性能的影响：随着处理浓度、温湿度以及时间的递增，齿板试件承载性能变化无明显单调趋势，较为平缓。随着处理周期的逐渐增加，会由于规格材先破坏而导致实验失败，结构失效。 总体看来，在高温高湿高盐环境下，木结构握钉力性能最易受环境的影响，而木结构齿板抗拉性能在三高环境下最为稳定。故三高环境下，相比于木构件钉连接，齿板的力学性能更为稳定，更适用于沿海地区建筑用材。
[Abstract]:Against the background of low carbon in China, the prospect of wood structure building and its related wood industry is becoming more and more popular. Especially in coastal areas, such as Hainan, where real estate has entered a period of rapid development in recent years, the development of tourism resources is in full swing, and the demand for wooden structures is very strong. However, the local "sunshine, typhoon, rainfall" three strong forces, The climatic and environmental characteristics of "high temperature, high humidity and high salt" make the requirements of weathering resistance, wind resistance and corrosion resistance of wood structure building materials greatly improved. China is a country with obvious regional differences, and climate conditions vary greatly from place to place. After construction and construction of wooden structures for some time, it will be found that structural materials and exterior finishing materials will produce cracking and discoloration. The decrease of strength affects the safety of wood structure. In this paper, the effects of high temperature and high humidity and high salt environment on the properties of wood structure building materials are studied. Through simulating different temperature and humidity environment and different concentration of salt solution, the holding force of specification material, shear property of oriented particleboard and bearing capacity of tooth plate were tested and analyzed respectively. The results showed that the surface and side holding force of the specification material was about 4.27 times of that of the end face nail holding force. The strength of holding nail on three sides is affected by three high environment, humidity and salt have great influence on it, and temperature has little effect on the standard material. With the increase of humidity and salinity, the nail holding force on the three sides of the specification will gradually decrease, and the difference between the salinity gradient is significant. With the increase of high temperature and high humidity treatment cycle, the holding force of specification material decreases gradually, and with the increase of salt treatment cycle, the holding force of specification material increases first and then decreases. When the concentration of salt solution increased 0.5%, the holding force of each side decreased to about 1%, and there was a certain regularity in the process of change. The functional formula of the change of each side holding force with the period of high temperature and high moisture treatment was as follows: the surface holding force was yr 2.5317x 42.435, the side grip force was yr 2.6143x 43.589, and the end face holding nail force was yr -0.7648x 15.716. In the above formula, x represents the number of cycles in the process and y represents the holding force at this time. The influence of high temperature and high humidity and high salt environment on the shear resistance of wood structure nail joint: humidity and salt had great influence on it, but temperature had little effect on it. With the increase of salt concentration and temperature and humidity, the elastic deformation stage is shortened, the plastic deformation stage is prolonged, and the yield load is smaller. There will be a slight rise in the middle. In high temperature and high humidity treatment, the design value of ultimate load will be reached when the treatment cycle reaches 48 cycles. The corresponding regression curve can be obtained. The influence of high temperature and high humidity and high salt environment on the tensile properties of wood structure tooth plate: with the increase of treatment concentration, temperature, humidity and time, the load-bearing performance of the tooth plate has no obvious monotonic trend and is relatively flat. With the increasing of the treatment cycle, the failure of the test and the failure of the structure will be caused by the first destruction of the specification material. In general, under the environment of high temperature, high humidity and high salt, the grip strength of wood structure is the most easily affected by the environment, while the tensile performance of wood structure tooth plate is the most stable in the three high environment. Therefore, the mechanical properties of the tooth plate are more stable than that of the wood component nail connection under the three high environment, and are more suitable for building materials in coastal areas.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU366.2;S781
[Abstract]:Against the background of low carbon in China, the prospect of wood structure building and its related wood industry is becoming more and more popular. Especially in coastal areas, such as Hainan, where real estate has entered a period of rapid development in recent years, the development of tourism resources is in full swing, and the demand for wooden structures is very strong. However, the local "sunshine, typhoon, rainfall" three strong forces, The climatic and environmental characteristics of "high temperature, high humidity and high salt" make the requirements of weathering resistance, wind resistance and corrosion resistance of wood structure building materials greatly improved. China is a country with obvious regional differences, and climate conditions vary greatly from place to place. After construction and construction of wooden structures for some time, it will be found that structural materials and exterior finishing materials will produce cracking and discoloration. The decrease of strength affects the safety of wood structure. In this paper, the effects of high temperature and high humidity and high salt environment on the properties of wood structure building materials are studied. Through simulating different temperature and humidity environment and different concentration of salt solution, the holding force of specification material, shear property of oriented particleboard and bearing capacity of tooth plate were tested and analyzed respectively. The results showed that the surface and side holding force of the specification material was about 4.27 times of that of the end face nail holding force. The strength of holding nail on three sides is affected by three high environment, humidity and salt have great influence on it, and temperature has little effect on the standard material. With the increase of humidity and salinity, the nail holding force on the three sides of the specification will gradually decrease, and the difference between the salinity gradient is significant. With the increase of high temperature and high humidity treatment cycle, the holding force of specification material decreases gradually, and with the increase of salt treatment cycle, the holding force of specification material increases first and then decreases. When the concentration of salt solution increased 0.5%, the holding force of each side decreased to about 1%, and there was a certain regularity in the process of change. The functional formula of the change of each side holding force with the period of high temperature and high moisture treatment was as follows: the surface holding force was yr 2.5317x 42.435, the side grip force was yr 2.6143x 43.589, and the end face holding nail force was yr -0.7648x 15.716. In the above formula, x represents the number of cycles in the process and y represents the holding force at this time. The influence of high temperature and high humidity and high salt environment on the shear resistance of wood structure nail joint: humidity and salt had great influence on it, but temperature had little effect on it. With the increase of salt concentration and temperature and humidity, the elastic deformation stage is shortened, the plastic deformation stage is prolonged, and the yield load is smaller. There will be a slight rise in the middle. In high temperature and high humidity treatment, the design value of ultimate load will be reached when the treatment cycle reaches 48 cycles. The corresponding regression curve can be obtained. The influence of high temperature and high humidity and high salt environment on the tensile properties of wood structure tooth plate: with the increase of treatment concentration, temperature, humidity and time, the load-bearing performance of the tooth plate has no obvious monotonic trend and is relatively flat. With the increasing of the treatment cycle, the failure of the test and the failure of the structure will be caused by the first destruction of the specification material. In general, under the environment of high temperature, high humidity and high salt, the grip strength of wood structure is the most easily affected by the environment, while the tensile performance of wood structure tooth plate is the most stable in the three high environment. Therefore, the mechanical properties of the tooth plate are more stable than that of the wood component nail connection under the three high environment, and are more suitable for building materials in coastal areas.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU366.2;S781
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