الفهرس 
LITERATURE REVIEWOnly 14 pages are availabe for public view
 |  | from | 244 |  |  |
| | | from | 244 | | |
Abstract
Prestressed Precast Hollow Core (PPHC) slabs are widely used for concrete
structures all over the world, primarily as floor or wall units in residential, industrial, and commercial buildings. While generally associated with mass produced, highly
repetitive buildings, they are also used in parking buildings, bridges and other heavy one-off structures. In some cases, it is required to make openings in the slabs for some reasons such as making ducts for electrical purposes, water and sewage pipes.
These unforeseen openings are not taken in consideration during design. The object of the research work is to investigate the effects of making openings in hollow core slabs (HCS) in different locations (flexural and shear) and study the efficiency of
using different strengthening techniques. Two experimental test programs were carried out on full-scale PPHC slabs. The first test program was performed on four
PPHC slabs (at Reinforced Concrete Laboratory (Prof. Monir Hussein Lab.), Faculty of Engineering, Menoufia University, Egypt) one slab is considered as control slab.
Two slabs one with opening at mid-span and the other one contains opening at mid of one-third of span. Two specimens with identical central openings, one is strengthened with GFRP laminates and the second one strengthened with steel plates.
The last two specimens used the same strengthening techniques as previous
specimens but the opening location was at mid of one third span. The second
experimental test program was carried out (at Durham School of Engineering,
University of Nebraska Omaha, NE, USA) on four specimens, each one was tested
twice from both ends (eight tests). One specimen was considered as a control slab, the second one contains an opening at max shear location (400 mm from the support), the third specimen had an opening at the same location and the two cores beside the
opening were filled with non-shrinkage grout to substitute the removed concrete part from shear section, and finally for the last specimen the two cores were filled by Ultra High Performance Concrete (UHPC).
PPHC slabs are analyzed using three dimensional nonlinear finite elements
to simulate different tests specimens and validate the results of experimental tests.
The experimental and numerical results are presented, compared and discussed. The proposed models in the analysis gave good results that agreed with the experimental tests results.