出版社：The International Institute for Science, Technology and Education (IISTE)
摘要：This study displays an experimental investigation on one form of embedded shearhead called( collar head reinforcement) as shear reinforcement and it displays also theefficient uses of different forms of reinforced concrete . Also it displays the efficient of existence of opening on punching shear strength of reinforced concrete flat plate. In the present research, ten specimens are tested with dimensions (1000x1000x75 mm) which are divided into two groups; the first group is a normal strength concrete with a compressive strength 30MPa; the second group is high strength concrete with a compressive strength 60MPa. Each group consists of five specimens, the first specimen is reference specimen R , and second specimen with opening adjacent to the column but without collar head No 1, and third specimen] with presence of openings adjacent to the column and with collar head reinforcement on both sides of the column towards the opening (horizontal) No 2, and fourth specimen with presence of openings adjacent to the column and with collar shear head reinforcement on both sides of the column away from the opening (vertical) No3, fifth specimen with presence of opening and with collar headreinforcement in all sides the column and extend to the opening No 4. The percentage of cracking load to ultimate load capacity was between (40 –48.5)%. By using collar shearhead around the column sides and extended to the opening, the cracking load can be increased to 100% . In flat plate with opening, the deflection and crack width can be decrease by using collar head around the column and extend to the opening and by increasing the compressive strength of concrete of the section.. The slabs which had openings adjacent to the column but strengthened with collar head, the percentage of the critical section perimeter was between (107.5 – 128.3) % that was reflected to the capability of this type of shear reinforcement(collar head) in compensation the shortfall in the critical section due to the existence of openings..
关键词：key words; flat plate ; high strength ; opening
