Study On The Minimum Longitudinal Reinforcement Ratio Of Specially Shaped Columns And The Effect Of The Thickness Of Concrete Cover On The Flexural Load-bearing Capacity Of Rectangular Columns

Specially shaped reinforced concrete columns have been used widely in civil engineering field in recent years on account of their superiority. Therefore studying for this new structure has some theoretical significance and practical value. In this paper, according to the regulation of minimum longitudinal reinforcement ratio in the national trade standard, Technical Specification for Concrete Structures with Specially Shaped Columns, which is used to guide the design and construction of structures with specially shaped columns, I propose my own views and suggestions.This paper also studies on the flexural load-bearing capacity of rectangular columns. It's known that the flexural load-bearing capacity changes with the thickness of concrete cover, so the second part of the paper is to draw the conclusion of the relationship between the flexural load-bearing capacity and the thickness of concrete cover, then get the value of M x and M y to realize the rapid reinforcement.Based on the existing research achievements, the theoretical and experimental researches on the RC structures with specially shaped columns, and the primary work are included as follows.1. Through the comparison of the regulation of minimum steel ratio for different countries and the analysis of the regulation of our national code, cross-shaped, T-shaped and L-shaped columns' normal section bearing capacity is calculated under different reinforcement form. Then plot the N-M interaction curves and compare and analyse the results, finally puts forward the reasonable amendments.2. The effect of thickness of concrete cover on the flexural load-bearing capacity changes with section dimension, steel strength, steel diameter, concrete strength and axial compression ratio. Using the orthogonal experiment, it comes to the conclusion that the steel diameter, axial compression ratio as the main factor, steel strength as the secondary factor, concrete strength is almost negligible. While the section dimension's influence reflects in the number of steel in the configuration, and different section dimensions with the same configuration have much the same results.3. Calculate the flexural load-bearing capacity of rectangular columns under different factors at some levels in the use of the fiber model method . According to the analysis results, fitting curves are created with Origin, finally get the function relation between the results and each factor.