Kajian ini dilakukan untuk menyiasat pengaruh dua lapisan bar tetulang terhadap kekuatan lenturan dan kekuatan ricih rasuk konkrit bertetulang. Dalam tahun-tahun kebelakangan ini, negara maju dan membangun berminat dalam penyelidikan untuk meningkatkan lenturan dan kekuatan ricih rasuk. Oleh itu, tujuan penyiasatan ini adalah untuk memperoleh sumbangan dua lapisan bar tetulang terhadap peningkatan kekuatan lenturan dan ricih rasuk. Dalam kajian ini, dua parameter telah digunakan iaitu bar tetulang membujur ditambahkan ke dalam lapisan tetulang utama rasuk tanpa tetulang rakap dan bar tetulang melintang ditambahkan dalam lapisan tetulang utama rasuk dengan jarak yang berbeza. Sebanyak 12 spesimen rasuk dengan dimensi 1280 mm x 220 mm x 270mm telah disediakan. Semua spesimen rasuk mengunakan konkrit gred 40 MPa yang dikawal oleh dua parameter utama. Keputusan yang diperolehi menunjukkan bahawa kekuatan lenturan dan ricih rasuk konkrit bertetulang bertambah baik dengan pengaruh dua lapisan tetulang. Di bawah pengaruh dua lapisan tetulang, pesongan rasuk spesimen dapat dikurangkan dengan mengurangkan jarak antara tetulang rakap disediakan bersama-sama lapisan dalaman tetulang. Kawalan keretakan yang lebih baik boleh didapati dengan meningkatkan kawasan keratan rentas tetulang rakap bersama-sama lapisan dalaman tetulang Akhirnya, keputusan eksperimen dibandingkan dengan kaedah teori yang tertera di dalam BS 8110: Part 1: 1997. Keputusan teori didapati kurang daripada keputusan eksperimen yang diperolehi Dengan menggunakan kaedah BS 8110, kekuatan lenturan teori rasuk konkrit bertetulang menunjukkan julat yang boleh diterima dengan keputusan eksperimen diperolehi. Walau bagaimanapun, kaedah ini tidak sesuai digunakan untuk menentukan kekuatan ricih teori rasuk konkrit bertetulang.
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This experimental work was carried out to investigate the influence of doubled reinforcement on the flexural and shear strength of reinforced concrete beam. In recent years both developed and developing countries are interested in research that enhance the flexural and shear strength of beam. Therefore, the purpose of this investigation is to determine the contribution of double layers of reinforcements on the enhancement of flexural and shear strength of beam. In this investigation, two parameters were used which were the longitudinal reinforcement to be inserted inside of main reinforcement of the beam without stirrups and transverse reinforcement to be inserted inside of main reinforcement of the beam with different spacing. A series of specimens of beam with dimension of 1280 mm x 220 mm x 270 mm were prepared. All the beam specimens were fabricated with concrete grade of 40 MPa and controlled by two main parameters. The results obtained revealed that the flexural and shear strength of reinforced concrete beam had been improved with the influence of double layers of reinforcements. Under the influence of double layers of reinforcements, the deflection of beam specimen had been reduced with the reduction of the spacing of stirrups provided along the inner layer of reinforcement. Better cracking control was provided by increasing cross-section area of stirrups along the inner layer of reinforcement. Finally, the experimental results were compared with the theoretical method as stipulated in BS 8110: Part 1: 1997. The theoretical results were found to be less than the experimental results obtained. By using BS 8110 method, the theoretical flexural strength of reinforced concrete beam showed acceptable agreement with experimental results obtained. However, this method was not suitable to be used for determining the theoretical shear strength of reinforced concrete beam.
Influence of doubled reinforcement on flexural and shear strength of reinforced concrete beam / Loh Chong Song