Experimental Research On Bonding Properties Between 150MPa High Performance Concrete And Deformed Bars

Nowadays, with the increase of height, span, volume and carrying capacity in architectural structures, the mechanical properties, workability and durability of concrete should meet the higher requirements. Thus, high strength and high performance concrete was brought into being in response to the proper time and conditions.The high strength and high performance concrete is endowed with excellent characteristics compared to the traditional type, such as high strength, durability, workability and volume stability. Therefore, the section sizes of building elements and the structural weight can be effectively reduced, the decrease of material consumption leads to the reduction of construction costs; meanwhile, the concrete can take full advantage of its high strength steel to enhance the seismic performance of the whole structure. Due to its wide application in the construction of high-rise buildings, super high-rise buildings, large-scale bridges and so on, it is considered as a new research interest in concrete technology in the future by all experts and scholars at home and abroad in this field.In this paper, precise classification about 14 groups of 5 typical specimens were done in accordance with the research on the design of mix ration, performance optimization, mechanical properties and durability of 150 MPa high performance concrete, which was carried out by China State Construction Ready Mix Concrete Co. Ltd Technology Center. Firstly, the pull-out test was adopted to systematically analyze the influence with regard to diverse concrete strength, thickness of concrete cover, rebar diameter, anchorage length and stirrup ratio on bonding and anchoring performances between 150 MPa high performance concrete and deformed steel, at the same time, the different bonding and anchoring performances between 150 MPa high performance concrete and ordinary concrete was studied; the test data was used to obtain the formula of maximum bond stress between 150 MPa high performance concrete and deformed steel and figure out the bond-slip constitutive relation through statistical regression. Secondly, partial bond-slip test was conducted to investigate the distribution of bond stress related to 150 MPa high performance concrete and deformed steel according to anchorage length of steel bar under different anchorage systems. Finally, based on the reliability analyses, the design of anchorage length about deformed steel and the construction of beam-column joints in 150 MPa high performance concrete were proposed. In a word, this study may provide a basis for further research and engineering application of 150 MPa high performance concrete.