Another option is to carry out an initial prestress
pe]--effective stress transferred to the pretensioned member (which considers the prestress
losses due to elastic shortening, conditioned by the concrete's modulus of elasticity).
At an approximate contract value of $570,000, Oldcastle Precast - Central Pre-Mix Prestress
manufactured and delivered the prestressed
concrete Super Girders: (5) five Super Girders at 157'-8” long; (5) five Super Girders at 154'-8” long and (5) five Super Girders at 170'-2” long.
The experimental program was developed with two main objectives: to study the time evolution of the prestress
applied to the structure and to verify the bridge structural behavior under the action of loads simulating the action of a vehicle.
and wave-material interactions are described for nonlinear propagation of longitudinal waves in materials (i) with inhomogeneous prestress
and (ii) with weakly variable physical properties.
DETERMINATION OF SHORT-TERM AND LONG-TERM PRESTRESS
The effect of prestress
is implemented as an increase in the tensile strength of the rammed earth material considering the direction and magnitude of the prestressing force.
The results of the tests show that the prestressed
GFRP-glulam beams exhibited a 38 percent increase in allowable bending stresses compared with reinforced GFRP-glulam beams without prestress
and an approximately 95 percent increase compared with unreinforced glulam beams.
force is measured and verified in place before each layer is individually bonded.
concrete bridge girders, the center of the prestress
force generally lies lower than the neutral axis of the section.
The SCC girders performed comparably to conventional concrete girders, with measured prestress
losses generally agreeing with predictions.