Study On The Performance Of HPFL Strengthening RC Column Under Axial Load Along With High Temperature

The technology of reinforcing structure is being applied more and morewidely. HPFL reinforcing layer is a pattern of inorganic gelling materialof cement paste. Its property is similar with concrete, what’s more, itsonly25mm thick. All this made the method of HPFL reinforcing layerhave a good performance of more prominence reinforce effect, easierconstruction, lower cost, better endurance and longer resist agingcontrast to tradition method of reinforcing. So, its application increasesday by day. But, the risk of reinforcement structure suffered from fire isincreasing. Base on this situation, we carried out an experiment to studyon HPFL reinforcement of RC columns under axial load and hightemperature. In order to study its performance completely, we havemade a contrast test on ten columns of the same dimension inconstructing under axial load along with high temperature (nine ofwhich were used HPFL reinforcing) to two columns experiment withaxial load at room temperature (one column was used HPFL reinforcing).All columns were made at the same time and maintained under the samecondition. The theory analyze based on the experimental data.The research contents and achievements as follows:1.Use the methods of model experiment associate with theoreticalanalysis. Study on the cross section temperature field of HPFLreinforcing column under axial load. Under the condition of800℃andconstant load, fit the increasing temperature curve of concrete columnand give the calculation formula of upper limit and lower limittemperature on different points. HPFL reinforcement layer has aperformance of thermal diffusion, which reduces heat energy transferinto concrete column deeply, so the HPFL reinforcing layer can proctetoriginal column under high temperature condition.2.Contrast research on the deformation performance of HPFLreinforcement RC columns under the process of axial load to enhance temperature along with constant load. The horizontal strain of HPFLreinforced RC columns can be reduced under axial load and stands withhigh temperature or normal temperature versus the strain of originalcolumns. Under the condition of constant temperature and constant load,the horizontal strain of reinforcement RC column is a binomial of time.3.Study on the residual bearing capacity of HPFL reinforcing RCcolumns under axial load and put forward a simplified method tocalculate. Put up the calculation model of residual bearing capacity andtemperature field with some reasonable assumptions. The result isaccord with the test. So, the calculate model and the formula have agood reliability and practicability.