BALOK BETON BERTULANGAN EKSTERNAL

Abstract

Tujuan penelitian untuk mengetahui kapasitas dukung balok beton dengan pemasangan tulangan lips channel di luar dengan penambahan mur dan baut. Penelitian ini menggunakan 5 benda uji sebagai sampelnya, yaitu B- Ø16-170= balok dengan tulangan besi polos Ø16 dan sengkang praktis jarak 170 mm, B-LC-875= dengan tulangan lips channel, sengkang praktis jarak 875 mm dan tanpa baut, B-LC-170= dengan tulangan lips channel, sengkang praktis jarak 170 mm dan tanpa baut, B-LC-170+BL= dengan tulangan lips channel, sengkang praktis jarak 170 mm dan baut lurus sejajar jarak 80 mm dan B-LC-170+BZ= dengan tulangan lips channel, sengkang praktis jarak 170 mm dan baut zig-zag jarak 80 mm. Pengujian balok bertulangan eksternal dilakukan di laboratorium dengan memberi beban terpusat di tengah balok, kemudian diamati perilaku balok saat menerima beban. Hasil pengujian akan didapatkan nilai P (beban), Δ (lendutan), grafik hubungan waktu-beban, hubungan tegangan-regangan, hubungan beban-lendutan dan hubungan lendutan-tegangan. Hasil penelitian menunjukkan bahwa balok bertulangan eksternal B-LC-170, B-LC-170+BL dan B-LC-170+BZ memiliki nilai kuat geser (V_u) yang lebih besar dari balok B-Ø16-170. Kuat geser aktual (V_u) pada balok B-LC-170 meningkat sebesar 17,45% terhadap balok B-Ø16-170, balok B-LC-170 meningkat sebesar 16,94% terhadap balok B-Ø16-170 dan balok B-LC-170+BZ meningkat sebesar 22,22% terhadap balok B-Ø16-170. Balok B-LC-875 mengalami penurunan dikarenakan balok mengalami slip pada beban 26kN. Balok B-LC-170+BZ memiliki nilai V_u yang lebih besar dari pada balok bertulangan eksternal yang lainnya, dengan demikian pemasangan baut zig-zag lebih optimal menahan beban dari pada baut lurus sejajar.

Kata kunci: lips channel,  slip, baut, mur

The purpose of the study to determine the carrying capacity of the beam with the installation of reinforcement lips channel in concrete beams with the addition of nuts and bolts. This study uses 5 specimens as the sample, namely B-Ø16-170= beams with Ø16 reinforcement plain iron and cross bar practically spacing of 170 mm, B-LC-875 = with reinforcement lips channel, cross bar practical a distance of 875 mm and without bolts, B-LC-170 = with reinforcement lips channel, cross bar practical a distance of 170 mm and without bolts, B-LC-170+BL= with reinforcement lips channel, cross bar practical a distance of 170 mm and bolt straight distance 80 mm and B-LC-170+BZ= with reinforcement lips channel, cross bar practical a distance of 170 mm and bolt zigzagged distance 80 mm. Testing of reinforced concrete beam external were performed in the laboratory by providing concentrated load in the center of the beam, then the specimen  be learned the behavior of beam while receiving the load. The test results will be obtained value P (load), Δ (deflection), relation chart the load-time, the stress-strain relation, the load-deflection relation and deflection-voltage relation. The results showed that reinforced concrete beam external B-LC-170, B-LC-170+BL and B-LC-170+BZ has a shear strength (V_u) value greater than beam B-Ø16-170.Actual shear strength (V_u) on beam B-LC-170 increased by 17.45% of the beam B-Ø16-170, beam B-LC-170+BL increased by 16,94% of the beam B-Ø16-170 and beam B-LC-170+BZ increased by 22,22% of the beam B-Ø16-170. Beam B-LC-875 experienced a decline due the beam experienced to slip on load 26kN. Beams B-LC-170+BZ has a shear strength (V_u) value greater than beam reinforced concrete beam external other, thus mounting bolt zigzagged more optimally support weight of than the bolt straight parallel.

Keywords: lips channel,  slip, bolt, shear strength