Experimental Study On Bond Behaviour Between Steel Rebars And Recycled Aggregate Thermal Insulation Concrete

Recycled aggregate thermal insulation concrete(RATIC) is a new type ofgreen concrete. Specifically, it inherits the basic mechanical property of thetraditional concrete, combines recycled aggregates and insulation aggregatescience from the mesoscopic level and is a structured green concrete with heatpreservation function. This concrete integrates the resource recycling, buildingenergy conservation and emissions reduction, whose application satisfies theneeds of sustainable development of the national construction industry in ourcountry and is an effective way to reduce greenhouse gas emissions and realizethe construction of low carbon energy saving.Combining the RATIC with the good performance bond anchorage is therequirement for its application in practical engineering. This paper is based onthe stability mixture ratio tests in our group and make experimental andtheoretical analysis on the bond anchorage performance of the steel rebars andthe RATIC. These main research works are listed as below:(1) Experimental research of the bonding anchorage of the regenerativethermal insulation concrete. Specifically, this paper use the center pull testmethod to study the bonding anchorage performance in thermal insulationconcrete, mainly consists of the influence rule of five factors such as thedifferent strength, recycled aggregate replacement rate, anchorage conditions,steel rebars diameter and age on the bonding anchorage performance and furtherset up the calculation formula of the ultimate bond strength of the regenerativethermal insulation concrete specimen. Finally, considering the formulaapplicability, we combine the current structure design standard and reliability analysis method, and give anchorage length suggestions of the steel rebars inregenerative thermal insulation concrete.(2) Model research on the bond-slip constitutive relation in the regenerativethermal insulation concrete. In this paper, the existing four bond-slip curvemodel is adopted to make regression fitting to the experimental test data in thebond-slip tests. Utilizing the comparison and analysis on these obtained relationmodels, we applies the model into ABAQUS finite element simulation and getthe curve model that is more consistent with the experimental curve. The resultsshow that the model is suitable for describing the bond-slip constitutive relationof the regenerative thermal insulation concrete.Through test and theoretical analysis in this paper, we obtain the suggestionformula on the ultimate bond strength between the steel rebars and the RATIC,the design value of the anchorage length of the ribbed steel rebars and thebond-slip constitutive relation model in the RATIC. Researches indicates thatthe anchorage length of the RATIC can be designed according to the designstandard of the ordinary concrete structure. Our works in this paper can supplytheoretical basis for popularization and application of the RATIC.