The widths of cracks are highly influenced by degree of bond developed between concrete and steel and stress corrosion cracking results from combined action of corrosion and static tensile stress which may be eir residual or externally applied.

The analysis of stresses developed in a prestressed concrete structural elements is based on following assumptions: Concrete is a homogeneous elastic material, Within range of working stresses, both concrete and steel behave elastically, notwithstanding small amount of creep which occurs in both materials under sustained loading, a plan section remains plain even after bending.

In general bonded beams are preferable due to ir higher flexural strength and predictable deformation characteristics, after onset of cracking stress in steel increases at a faster rate in both types of beams since steel does not reach its ultimate strength in case of unbounded beams ultimate load supported by beam is smaller than that of bonded beam in which steel attains its ultimate strength at failure stage of member.

Equivalent moment for cable provided for given loading condition is W= 8Pe/L²
and Camber provided for cable is 5WL⁴/384EI.

The rate of increase of stress in tendons of a prestressed concrete member under loads depends upon degree of bond between high tensile steel wires and surrounding concrete, increase of stress in steel depends on average strain in concrete at level of steel.

The bending moment at centre of span is M_g = (0.125�1.57�8²) = 12.56knm
M_q = (0.125�2.50�8²)=20knm, Total moment M = (M_g+M_q)=32.5knm
P = (M/e) = (32.5�103/150) = 217kn.

The tensile stresses are developed when cracks become visible at soffit of beams depend upon type and distribution of steel reinforcement and quality of concrete in beam, at soffit of beam concrete behaves according to influencing parameters of steel reinforcement.

The notations and sign conservations used for analysis of prestress are
P-Prestressing force, e-eccentricity of prestressing force, m ? p � e ? moment
A ? Cross sectional area of concrete member, I ? second moment of area of section about its centroid.