Fire Resistance Experimental Study Of New Type Steel Reinforced Concrete Columns With Special-shaped Cross Section

The steel reinforced concrete columns with special-shaped cross section consist ofL-shaped, t-shaped and cross-shaped special-shaped section columns instead of thegeneral reinforced concrete rectangular or square frame column as the vertical form thecomposition structure. In order to avoid frame column appeared interior edges andcorners in architectural,and increasing indoor useful area,improving the architecturebeautiful to look at,making to decorate the furniture and interior decoration etc manyperformance advantages. For residential,bringing more flexible and convenient to usefulfunction with building design.Now, For fire resistance and fire resistance design, thefire damage assessment method of the round steel tube concrete column, square steeltube concrete column and rectangular concrete-filled steel tube column,have to carry onthe thorough theoretical analysis and experimental research.But for new type stellreinforced concrete columns with special-shaped cross section,the fire test research alsois a blank.So this article carry on fire test research and theoretical analysis of the fivesteel reinforced concrete columns with special-shaped cross section.The main contents including:(1) Carring on fire test research of the five steel reinforced concrete columns withspecial-shaped cross section,studing on fire resistance test research from the two aspectssuch as load ratio and fire protection layer thickness.(2)The test carry on following ISO834standard heating process.In test measure theaxial deformation and lateral displacement at middle height were observed, as well asthe concrete spalling and damage procedure of the columns and get the fireproof limit.(3) The experimental results show that: new type steel reinforced concrete columns with special-shaped cross section because the internal heat of the core concrete, hasgood fire resistance.(4) Parameters were studied to investigate their influences on fire resistance of loadratio and fire protection layer thickness. The experimental results show that: axial loadratio and fire protection layer thickness have significant effect on fire resistance of newtype steel reinforced concrete columns with special-shaped cross section. The load ratiois more greater, the performance is more poorer. In the same way,the fire protectionlayer thickness is more thiner,the performance is more poorer.And the rules andregulations get the fire protection layer thickness of the steel structure column does notapply to new type steel reinforced concrete columns with special-shaped crosssection.Comparing with the fire protection layer thickness of steel structure columnstipulated in the specification, fire protection layer thickness of new type steelreinforced concrete columns with special-shaped cross section is about15%of the steelstructure column.(5) Through the analysis and on the basis of numerous parameter analysis,giving asimplified way to determine the fire of bearing capacity and fire protection layerthickness of practical, which may give a reference to engineering applications.