Numerical Analysis On Crack-Resistance Behavior Of Prestressed Block Masonry

As a new kind of masonry material,the small-sized concrete hollow blocks have many advantages,such as:enviroment protection,land reservation and energy saving,easy fabrication and so on,satisfied with the trends of the contemporary masonry structural material. In recent years,they have been widely used in urban buildings of our contury. However,because the shear strength and the tensile strength of the block masonry wall are low,and the vertical cracks are large,this kind of wall is easy to arise temperature cracks during the process of construction and use. How to improve masonry's cracking-resistance by effective technical measure becomes a question which engineering world is care about.Prestress the block masonry wall can not only change its behavior,inhibit the wall crack,improve masonry's cracking-resistance and shear capacity,but also expand masonry's application scope,fulfill the requirements of masonry development for tall-building and energy saving. Based on domestic and international researches, several tasks were made in this paper:1. After studying and analysing the shear section's failure mechanism of prestressed block masonry wall,nonlinear finite element analysis to different types and different structure measures of walls are proceeded by ANSYS,Stress distribution and crack shape in the wall are acquired.2. The main influence factors which affect the prestressed concrete block masonry wall's shear capacity and cracking-resistance capacity are explored. Based on the finite element analysis results and summarizing the experimental results in the past,the formular of ultimate shear capacity and cracking-resistance capacity of prestressed block masonry wall are established.3. The design methods and construction process of prestressed masonry structure are discussed,Some design methods and construction details are recommended.The following conclusions are gotten through the above studing:To prestress the block masonry wall is an effective method to improve its cracking-resistance and shear capacity. The finite element results compared with the preceding test are basically identical. The characteristic and atvantages of the prestressed block masonry structure are proved,which will provide us the theorestic basis to use of the prestressed masonry in engineering.