Electronic Theses and Dissertation

Penelitian ini membahas perkuatan balok beton bertulang yang mengalami gagal geser menggunakan matrix ferrofoam concrete berserat polyethylene. Tujuan penelitian adalah mengetahui pengaruh perkuatan terhadap kapasitas geser, perilaku lendutan, pola retak, dan regangan beton, serta membandingkan kinerja balok normal dan balok serat sebelum maupun sesudah diperkuat. Metode yang digunakan adalah eksperimen laboratorium pada dua benda uji balok berukuran 150 mm x 300 mm x 2200 mm, yaitu balok normal dan balok serat, yang keduanya telah mengalami gagal geser lalu diperkuat dengan lapisan matrix ferrofoam concrete berserat polyethylene, sedangkan balok normal diperkuat dengan tambahan injeksi epoxy resin. Hasil penelitian menunjukkan bahwa perkuatan mampu meningkatkan kapasitas geser balok. Balok normal yang semula memiliki beban maksimum 16,95 ton dengan lendutan 8,11 mm setelah diperkuat menjadi 22,38 ton dengan lendutan 14,85 mm, sedangkan balok serat yang semula memiliki beban maksimum 21,23 ton dengan lendutan 14,38 mm setelah diperkuat menjadi 22,76 ton dengan lendutan 17,61 mm. Pola retak setelah perkuatan tetap menunjukkan karakteristik kegagalan geser, kapasitas ultimit meningkat, namun kekakuan balok tidak kembali. Dengan demikian, matrix ferrofoam concrete berserat polyethylene efektif sebagai material perkuatan balok gagal geser dan berpotensi menjadi alternatif retrofit pada struktur beton bertulang

This study discusses the strengthening of reinforced concrete beams that experienced shear failure using a polyethylene fiber ferrofoam concrete matrix. The objectives of the study were to determine the effect of reinforcement on the shear capacity, deflection behavior, crack patterns, and strain of concrete, and to compare the performance of normal beams and fiber beams before and after reinforcement. The method used was a laboratory experiment on two beam specimens measuring 150 mm x 300 mm x 2200 mm, namely a normal beam and a fiber beam, both of which had experienced shear failure and were then reinforced with a layer of polyethylene fiber ferrofoam concrete matrix, while the normal beam was reinforced with additional epoxy resin injection. The results showed that reinforcement was able to increase the shear capacity of the beam. The normal beam which originally had a maximum load of 16.95 tons after being reinforced became 22.38 tons with a deflection of 14.85 mm, while the fiber beam which originally had a maximum load of 21.23 tons after being reinforced became 22.76 tons with a deflection of 17.61 mm. The crack pattern after reinforcement still showed the characteristics of shear failure, but the crack development became more controlled and the ultimate capacity increased. Thus, the polyethylene fiber ferrofoam concrete matrix is effective as a reinforcement material for shear-failed beams and has the potential to be an alternative retrofit for reinforced concrete structures.