Research On Crack Width Calculation Of Reinforced Concrete Members With Circular Sections

Members with circular concrete sections have been used widely for piles in harbor engineering, columns of the building, bridge piers and support piles in deep foundation ditch engineering, etc. Many reinforced concrete members are cracking during their working time for the reason of small tensile strength of the concrete. Durability, safety and bearing capacity of the concrete members are affected obviously by the cracks. So the the crack width of the member must be calculated based on the application and durability of the structures except the calculation of the strength. Many theories of calculation and experimental studys on the concrete cracks have been developed by the researcher home and abroad, but only a little on the crack width calculation of the members with circular sections. This is the Revised matter of Deisign Code for Harbour Engineering Concrete Structure. The main Objective to develop Crack Width Calculation of Reinforced Concrete Members with Circular Sections which can be used in Harbour Engineering. Baseed on the require of the Revise, the main aspects of the research work are as follows:(1) Studying and analysis of the materials about the crack width of RC concrete members home and abroad to define the main effects. Compare the methods of crack control in the concrete code and discuss the influence of the crack width to the corrosion of the steel bar.(2) Twelve large eccentric compression specimens, twelve flexural specimens, twelve large eccentric tension specimens, twelve small eccentric compression specimens ,sixteen axial tension specimens are test and tensile strain of the steel bar and crack width under every class of load are obtained in this paper.(3) Equilibrium equation of force and bend which established through steel strain and compresion angle. Numerical analysis methods to solve the equation are given. The simplified equation which calculate the steel stress are established based on the results of the equilibrium equation.(4) Studying on the calculation of the crack width to establish the calculate equation of the effective ratio of the tensile steel bar and further simplified quation of the steel stress are given based on the experimental crack width.(5) The crack width of three RC piles are calculated by the equation which established in this paper.