Research On The Axial Compression Performance Of Steel Regeneration Recycled Aggregate Concrete After Fire

Steel Reinforced Recycled Aggregate Concrete(SRRAC) structures is an independent structure embedded steel in the recycled concrete. Its core part is steel, and its external for recycled concrete and with the right amount of longitudinal are bounded by pushing for reinforcement and the stirr up, SRRAC structure possesses the advantages of steel reinforced concrete and recycled concrete at the same time, has a broad application prospect.By reading of related literature at home and abroad to consider the temperature field of SRRAC short column under axial compression performance after fire test research is still in a blank state. in this paper, we did research on steel reinforced recycled aggregate concrete short columns under axial compression after fire, through test, numerical simulation and theoretical analysis methods.First, we configure the recycled concrete test blocks with different strength and different recycled coarse aggregate replacement ratio of recycled concrete. According to experiment condition, we simply analyzed the silica fum e and workability of the strength of recycled concrete, and makes a simple analysis on the working mechanism of recycled concrete, finally gives the proportion of C40 and C50 strength of recycled concrete.Second, replace rate of recycled coarse aggregate, the fire time and strength of recycled concrete for change parameters, 18 SRRAC short column in axial compression performance after the ISO- 834 standard fire test is designed(including 6 normal temperature contrast specimen). Through the experiments, we observe the failure process and the final failure pattern of the specimens, and obtain the fire process with measuring point temperature field and test data such as load-displacement curve. Through the analysis of experimental results, we concluded tha t, SRRAC specimen has good residual bearing capacity after fire compared with ordinary steel reinforced concrete specimen, and with the increase of recycled coarse aggregate content, the smaller SRRAC bearing capacity of the specimens after fire loss, but the bigger the recycled coarse aggregate content, specimen axial deformation is increased; by the time of fire had a great influence on SRRAC specimen residual bearing capacity after fire; recycled concrete strength of SRRAC specimen have little impact on the residual bearing capacity after fire.Third, on the basis of selecting reasonable steel and thermal parameters and constitutive relation of recycled concrete, analyzed the SRRAC under axial compression with short columns at normal temperature and after fire which has researched in the test by software of finite element analysis named ABAQUS, the results show: the temperature field numerical simulation results and mechanics analysis model are close to the test results, proves the rationality of the finit e element analysis model. In addition, it also analyzed the mechanical mechanism of the SRRAC under axial compression with short columns and the parameters affecting the rest of the bearing capacity of SRRAC under axial compression with short columns after fire and shows that: the bearing capacity of SRRAC under axial compression with short columns after fire reduced obviously, but residual bearing capacity of the SRRAC axial compression short column which contains more than 50% recycled coarse aggregate increase slightly by the time of fire exceed 60 min; the influence of strength of recycled concrete、recycled coarse aggregate replacement ratio 、the yield strength of steel and sectional steel ratio to residual bearing capacity is not obvious.Finally, according to the existing specifications and literature review, b y calculating cross-section bearing capacity of the SRRAC under axial compression with short columns at normal temperature and after fire, we can get: the calculated value of the SRRAC under axial compression with short columns at normal temperature is safer than the test value; the calculated value of the specimen after 60 minutes under the fire is 10% ~ 30% lower than the simulation value and test value, calculated value is safer; the calculated value of the specimen after 120 minutes under the fire is close to the test value and slightly lower than the simulation value, and they are in good agreement.The research in this paper shows that the steel regeneration recycled aggregate concrete under axial compression with short columns has a good performance after fire, so steel regeneration recycled aggregate concrete columns not only solved the problem of the construction waste process ing and energy regeneration, but also meet the requirements of the residual bearing capacity on engineering, and its potential applications are fantastic.