JIPKIC 结构热计原黑 Chapter 1 Basic Concepts of Reinforced Concrete Structure and Physical and Mechanical Properties of Materials
Chapter 1 Basic Concepts of Reinforced Concrete Structure and Physical and Mechanical Properties of Materials
JPKIC 结构计原黑 MAIN CONTENT Basic Concepts of Reinforced Concrete(RC) Strength and deformation of concrete under various stress conditions Type ,Grade and Mechanical Properties of Steel Reinforcement Bond between concrete and steel reinforcement
MAIN CONTENT ⚫ Basic Concepts of Reinforced Concrete(RC) ⚫ Strength and deformation of concrete under various stress conditions ⚫ Type ,Grade and Mechanical Properties of Steel Reinforcement ⚫ Bond between concrete and steel reinforcement
JIPKIC S1.1 The basic concepts of RC structures 箱构计原黑 1.Definition of RC Structure Reinforced concrete structures is a structure made of concrete configured by steel reinforcement and steel skeleton Production of reinforced concrete:the combination of steel and concrete work together.Concrete is in compression,and steel reinforcement is in tension,this fully play their advantages. Concrete:Non-homogeneous materials:high compressive strength,tensile strength is very low being (1/8~1/18)of compressive strength Steel reinforcement:high tensile and compressive strength. Often carry tension
§1.1 The basic concepts of RC structures • 1. Definition of RC Structure • Reinforced concrete structures is a structure made of concrete configured by steel reinforcement and steel skeleton. • Production of reinforced concrete: the combination of steel and concrete work together. Concrete is in compression, and steel reinforcement is in tension, this fully play their advantages. • Concrete: Non-homogeneous materials: high compressive strength, tensile strength is very low being (1 / 8 ~ 1 / 18) of compressive strength . • Steel reinforcement: high tensile and compressive strength. Often carry tension
P P P D 9 Simply supported Continuous beam beam stnuctuTGS RC plate P Column
RC plate P P P e P Column e Simply supported beam P P P P Continuous beam RC structures
JPKic 结构盘计原黑 Proems Why should steel rebar be set in common plate, beams,columns? Analysis of some common phenomena of crack of plate and beam structures
Why should steel rebar be set in common plate, beams, columns? Analysis of some common phenomena of crack of plate and beam structures
JPKIC 构盘计原 Example:a span of 4m,a concentrated load at midspan of tested beam,beam section size is 200 X300mm,concrete is C20. Please see: 200 4000 A A一A 200 210 4000 B 316 b) B—B
Example: a span of 4m, a concentrated load at midspan of tested beam, beam section size is 200 ×300mm, concrete is C20. Please see: 4000 A A F a) 200 300 A－A b) 4000 B B B－B 200 300 210 316
JIPKIC 结构热计原黑 Testing results: In fig.a),for plain concrete beam,the ultimate load P=8kN, controlled by the concrete tensile strength,failure modes: brittle failure In fig.b),the ultimate load of RC beam P=36kN,the steel rebar is in tension,and concrete is in compression to crush, failure mode:ductile failure (appropriate steel reinforcement) This can be concluded:the effectiveness of combination of steel and concrete: 1,greatly enhance the load-carrying capacity 2,improve the mechanical performance of structure
Testing results: • In fig. a),for plain concrete beam, the ultimate load P = 8kN, controlled by the concrete tensile strength, failure modes: brittle failure • In fig. b) , the ultimate load of RC beam P = 36kN, the steel rebar is in tension, and concrete is in compression to crush, failure mode: ductile failure (appropriate steel reinforcement) • This can be concluded: the effectiveness of combination of steel and concrete: 1, greatly enhance the load-carrying capacity 2, improve the mechanical performance of structure
JPKIC 结构计原黑 2.Reasons for steel and concrete working together (1)a good bond strength between them (2)The temperature linear expansion coefficient are close steel a=1.2×10-5 concrete ac=1.0 ~1.5 x 10-5 (3)Steel rebar embedded in concrete,which can prevent steel from rust
2、Reasons for steel and concrete working together (1) a good bond strength between them (2) The temperature linear expansion coefficient are close (3) Steel rebar embedded in concrete, which can prevent steel from rust. steel st = 1.2 10–5 concrete ct = 1.0 ～ 1.5 10–5
JPKIC 结构设计原理 The principle of structure design 3.The main advantages and disadvantages of RC structures ·Advantages: 1)rich materials resource,saving steel 2)Durability 3)good fire resistance 4)mold well,easy realization of structural type; 5)A good structural integrity due to cast-in-site
3、 The main advantages and disadvantages of RC structures • Advantages： 1) rich materials resource, saving steel 2) Durability 3) good fire resistance 4) mold well, easy realization of structural type; 5) A good structural integrity due to cast-in-site
JPKIC Disadvantages: 结构势计原黑 (1 high self-weight solution Light aggregate material (2)Crack resistance is,work with cracks solution Prestressed concrete (3)Construction is impacted by climate conditions,the a long construction period (4)More mold tools and wood waste (5 )Difficult strengthening and reconstruction,poor heat and noise-resistance performance
⚫ Disadvantages： （2）Crack resistance is, work with cracks （3）Construction is impacted by climate conditions, the a long construction period (4 ) More mold tools and wood waste （5）Difficult strengthening and reconstruction, poor heat and noise- resistance performance. （1）high self-weight Light aggregate material Prestressed concrete solution solution