TY  - BOOK
AU  - Yahia Mohy El-Deen Mostafa Osman,
AU  - Hany Ahmed Abdalla
AU  - Ashraf Adel Shawky 
TI  - Torsion Behavior Of Recycled Aggregates Concrete Beams With Openings / 
U1  - 624.1772 
PY  - 2022///
KW  - Concrete beams
KW  - qmark
KW  - Recycled aggregate
KW  - R.C Beams
KW  - Opening; Rotation angle
KW  - Torsion
KW  - Torque
N1  - Thesis (M.Sc.)-Cairo University, 2022.; Bibliography: pages 65-66.; Issued also as CD
N2  - Due to the fast rise in material and transportation costs, the recycling of construction
waste has become a critical operation in the construction industry. With the rise in
construction and demolition operations in the construction sector, the relevance of this
process has grown even more. Furthermore, the environmental risks associated with
rising carbon emissions have made the recycling of construction debris an unavoidable
operation. Building debris that has been recycled can be utilized as aggregate in the
construction of a new reinforced concrete structure. Therefore, the use of construction
waste as coarse aggregate should be researched to ensure that the structural behavior of
these structures does not differ from that of non-recycled (natural) coarse aggregate
buildings (NCA).
An experimental investigation was undertaken in this study to explore the influence
of recycled coarse aggregate (RCA) on reinforced concrete beams with pure torsion
apertures. To research crack pattern, failure mechanism, failure load, torque-rotational
angle relation, load-strain relation for longitudinal reinforcement, opening and edge
stirrups, and toughness, various RCA ratios are utilized in the construction of RC beams.
Six beams with identical cross-sectional dimensions of 150 x 350 mm and a total span of
1400 mm are included in the investigation. The overall beam length was split into three
sections, with the center section serving as the test zone and measuring 1000 mm in
length. The two cantilevers were 200 mm wide and 350 mm long, and the tested beams
included two solid beams and four beams having 300 x 150 mm openings. The RCA
replacement ratios of the tested beams were separated into four groups: 0 percent, 30%,
50%, and 100%. At the ages of 7 and 28 days, six cubes are built from each group to
investigate compressive strength.
The results of the experiments revealed that the existence of an aperture in a beam
reduces cracking and ultimate torque. The results of concrete mixes with 30 percent and
50 percent RCA replacement ratios are nearly identical to those of conventional concrete.
When compared to concrete mixes with 30 percent, 50 percent, or standard RCA
replacement ratios, the concrete mix with a 100 percent RCA replacement ratio yields
worse outcomes. The crack patterns for the specimens manufactured with NCA and RCA
are identical, according to the tests done on RC beams. However, beams created with
30% and 50% RCA replacement ratios have about the same capacity and durability as
NCA-made beams. For beams with a 100 percent RCA replacement ratio, the results are
lower; يتناول هذا البحث دراسة عملية حول تأثير استخدام ركام كبير مُعاد تدويره في الكمرات الخرسانية ذات الفتحات و المعرضة لعزوم لي ،حيث تم اختبار ست كمرات خرسانية مسلحة ، اثنتان منهما بركام طبيعي إحداهما بدون فتحة و الاخري بفتحة .و الكمرة الثالثة فتم استخدام ركام كبير مُعاد تدويره بنسبة 30% مع وجود فتحة في منتصف الكمرة . و للكمرتين الرابعة و الخامسة فتم استخدام ركام كبير مُعاد تدويره بنسبة 50% و احدي الكمرتين بدون فتحة و الاخري بفتحة. الكمرة السادسة فتم استخدام ركام كبير مُعاد تدويره بنسبة100 %  بوجود فتحة أيضا.هدف هذا البحث هودراسة شكل الانهيار وحمل الكسر و العلاقة بين الحمل و الانفعال للحديد و كذلك عزم اللي و زاوية الدوران للكمر المُعاد تدويره.


ER  -