الفهرس 
Research Motivation
Serviceability of Prestressed Concrete BeamsOnly 14 pages are availabe for public view
 |  | from | 280 |  |  |
| | | from | 280 | | |
Abstract
Prestressed concrete is widely used in the construction industry in buildings,
bridges, towers, pressure vessels and offshore structures. In numerous
structures, the architectural requirements prescribe the incorporation of long
span and slender elements in which the prestressed concrete is rendered the
most feasible design alternative. The strength and serviceability of reinforced
concrete (RC) and prestressed concrete (PC) elements are generally affected
after fire exposure. The basic design objective for such elements would be life
safety and collapse prevention.
The main objective of this investigation is to the study behavior of statically
determinate prestressed concrete beams subjected to fire. In this respect, an
extensive experimental! analytical investigation was conduced on number of
medium scale post-tensioned concrete girders subjected to fire. The
experimental program consisted of testing twelve beams, fIve of which were
partially prestressed, five beams fully prestressed and the remaining two
beams are non prestressed beams. The beams had an overall width, depth and
length of 160, 340 and 4400 mrn, respectively. The beams were simply
supported with a clear span of 4000 mm. The prestressing strand had a harped
profile similar to the shape of the applied bending moment. The main test
variables are concrete compressive strength, concrete cover and prestressing
index. All prestressing specimens were cast using bonded prestressing
strands. The strands were stressed after the concrete had reached an age of 28
days, and then grouted with cementitous grout. The test program was divided
into two phases. Five beams were tested as control beams and the remaining
seven beams were loaded and exposed to fire at level of 600°C for a three
hours duration.