Problem 2 7 points What is the meaning of the following term

Problem 2: (7 points) What is the meaning of the following terms in Concrete Design -ACI: 2- Linear Strain Model 3- Creep 4- Nominal Flexural Moments 5- Camber 6- Ductile Failure 7- Skin Reinforcement

Solution

1)ACI: The American Concrete Institute is a non-profit technical society and standards developing organisation.Its mission is “ACI develops and disseminates consensus-based knowledge on concrete and its uses.

2)Linear Strain Model:The design of reinforced concrete beams usually consider a linear strain distribution over the cross section and despises the strains due to shear, because they are very small.In linear strain model,effect of normal pressure is negligible on stress distribution

3) Creep: Creep can be defined as the elastic and long-term deformation of concrete under a continuous load.

4) Nominal Flexural Moments: It is a material property, defined as the stress in a material just before it yields in a flexure test.

5)Camber:Camber is a curvature built into a member or structure so that when it is loaded, it deflects to a desired shape.

6) Ductile failure: It is a type of failure characterized by extensive plastic deformation or necking. This usually occurs prior to the actual failure of the material. In concrete design, ductile failure is desired as it generates a predictable form of failure such that the structure should not catastrophically collapse without prior warning.

7) Skin reinforcement: skin reinforcement is provided in a beam when the depth of the beam exceeds 750mm, or when there exists torsion in the beam, these reinforcement is provided for beams having depths greater than 450mm.Their main purpose is to prevent the lateral reinforcement from buckling.