Civil Engineering - RCC Structures Design - Discussion

What is dip? Please explain. @Shaifali.

Bending moment For a beam with point load = WL/4.
Now, Prestressing force = P * h.
P*h=WL/4,
h=WL/P4.

The prestressing moment(p*e) must develop the deflection of h=wl/4p.

Solution :p*h(e at Centre) =wl/4 (deflection due to point load at center).

Shift at any point = external moment/Prestressing force.
EM= wl/4 (for concentrated load),
Where.
Prestressing force = P.
Thus, shift at center = wl/4P.

What is central dip here?

Ra * L = W * L/2,
Ra = WL/2,
Moment at center (Central dip) = Ra * L/2,
Then hp = w/2 * l/2,
= wl/4,
So, h = wl/4p.

Thanks @Piyush Singh.

P is the prestressing tensile force given to the tendon or stressing wire which transfer the stress to the concrete either by adhesion (in case of prestressed pretension) or by anchorage (in case of posttensioned prestress) , Generally the wire/strand/tension is high tensile steel with tensile strength upto 1850 N/mm^2,

Concept is known as load balancing concept in which bending moment is balanced with the prestressing force.

Thus bending moment = Prestressing moment.

Wl/4 = P*h.

H = WL/4P.

W for P ok then how for e=l/4 comes?

P is load expressed in w.