Experimental Study On Mult I-axial Compressive Behaviour Of Recycled Aggregate Concrete After High Temperature

With the promotion of China's national strength,it's inevitably produces a large number of construction waste in the process of modernization.Recycled aggregate concrete referred to as recycled concrete,is a technology to make construction waste available.Developing recycled concrete technology can effectively solve the contradiction between development and environmental protection,has a good environmental benefits,social benefits and economic benefits.Fire is one of the most frequency major disasters that also has highest threat to public safety and social development,high temperature conditions has a great influence on the properties of deformation,stress distribution and bearing capacity of the concrete structure.Therefore,this paper has carried out the following research about the mechanical properties of recycled concrete under multi-axial compressive stress state after high temperature:(1)Three types of replacement rate(0%,50%,100%)of the recycled concrete block treated with high temperature(200 ?,400 ?),were conducted to the biaxial compressive test research,it is concluded that the changing rule of biaxial compressive strength,deformation law and the stress strain curve under the condition of different stress ratio,set up a corresponding failure criteria,and consider different temperature,different replacement rate how to affect the performance of the above rules.Research shows that:Biaxial compressive strength and peak strain after high temperature has certain increase compared with the uniaxial compression,under the condition of the same replacement rate,with the increasing of temperature,biaxial compressive strength is reduced,the peak strain increase;Under the same conditions of temperature,with the increasing of replacement rate,biaxial compressive strength is reduced,the peak strain increase.(2)Three types of replacement rate(0%,50%,100%)of the recycled concrete block treated with high temperature(200 ?,400 ?),were conducted to the triaxial compressive test research,it is concluded that the changing rule of triaxial compressive strength and deformation law and the stress strain curve under the condition of different stress ratio,set up a corresponding failure criteria,and consider the different temperature,different replacement rate how to affect the performance of the above rules.Research shows that:Triaxial compressive strength and peak strain after high temperature has great increase compared with the uniaxial compression,under the condition of the same replacement rate,with the increasing of temperature,triaxial compressive strength is reduced,the peak strain increase;Under the same conditions of temperature,with the increasing of replacement rate,triaxial compressive strength is reduced,the peak strain increase.