Stiffness Of Reinforced Concrete Walls

Aging and durability of concrete used in nuclear power plants.

Stiffness of reinforced concrete walls.

The purpose of this paper is to estimate the stiffness and strength of damaged rectangular reinforced concrete shear walls after an earthquake using surface crack patterns. Stiffness of reinforced concrete walls resisting in plane shear proceedings 4th symposium on current issues related to nuclear power plant structures equipment and piping orlando florida. Acknowledgments this research was funded by pacific earthquake engineering research center peer and the. Design of reinforced concrete walls are in many ways like columns.

Effective stiffness is a function of the applied loading and detailing of the component. Structural walls different to other flexural dominated components are sensitive to both shear and flexural stiffness degradations. Stiffness of reinforced concrete walls resisting in place shear tier 2. Strength reduced from 136 7 to 114 9 in kips.

Reinforced concrete walls are commonly used in power plant construction to resist earthquake effects. 2 5 clear to strength steel 5 12 rather than the designed 5 10 bending strength of the section has been reduced by about 16. After the initial cracking of wall concrete point a in fig. Block and concrete are strong in compression but weak in tension.

24a the shear stiffness of the rc wall deteriorates with the development of diagonal cracks and part of the shear load originally carried by the rc wall will be transferred to the src boundary columns thus cause an increased proportion of shear load carried by the boundary columns. Strength of reinforced concrete sections amount of rebar a s the project calls for 5 10 and 5 12 are used. Poured or cast walls must have horizontal steel top and bottom. Block cores must be filled with pea gravel concrete.

Tension compression flexure as well as different rates of loading impact short term long term. Aci 318 11 proposes taking the effective stiffness of cracked wall sections to be 0 35 of the elastic stiffness of the section and the uncracked stiffness to be 0 70. They often act as primary elements of a structure s lateral stability systems and by doing so are subjected to high in plane bending forces. Assessing the damage severity of buildings after an earthquake is an important part of the emergency inspection operation of buildings.

Seismic analyses of concrete structures under maximum considered earthquakes require the use of reduced stiffness accounting for cracks and degraded materials. Technical report monteiro p j m.