PERENCANAAN ULANG GEDUNG REKTORAT INSTITUT TEKNOLOGI NASIONAL YOGYAKARTA MENGGUNAKAN SISTEM BALOK PRESTRESS

Abstract

Abstrak

Pada struktur dengan bentang panjang, struktur beton bertulang biasa tidak cukup untuk menahan tegangan lentur sehingga terjadi retak-retak didaerah yang mempunyai tegangan lentur, geser atau puntir yang tinggi. Timbulnya retak pada penampang beton bertulang disebabkan pada saat terjadi tegangan elastis pada penampang,tegangan tarik sangat kecil sehingga tulangan beton bertulang tidak efektif menahan beban sehingga dikembangkannya suatu material baru seperti balok prestress. Balok prestress merupakan penerapan gaya pratekan pada balok sedemikian rupa sebelum dikerjakan beban laur,guna meniadakan tegangan tarik serat beton yang terjadi saat beban luar bekerja.

Dalam penelitian ini, variabel yang dikembangkan adalah tegangan tarik dan tekan,jumlah strand,lokasi tendon,gaya prategang awal,kehilangan gaya prestress serta penulangan non-prategang.

Berdasarkan hasil penelitian tersebut dapat disimpulkan balok prestress yang digunakan aman terhadap momen retak,gaya geser dan lendutan untuk digunakan dalam perencanaan.

Kata kunci—struktur, balok presstres , tegangan

Abstract

In long-span structures, ordinary reinforced concrete structures are not sufficient to withstand the bending stress so that cracks occur in areas that have high bending, shear or torsional stresses. The emergence of cracks in the reinforced concrete section is caused when the elastic stress occurs in the section, the tensile stress is very small so that the reinforced concrete is not effective in holding the load so that a new material is developed such as a pressure beam. A prestress beam is the application of a prestressed force to the beam in such a way before it is carried out by laur loads, in order to eliminate the tensile stress of the concrete fibers that occurs when the external load works.

In this study, the variables developed were tensile and compressive stresses, number of strands, tendon location, initial pre-stress forces, loss of prestress forces and non-prestressed reinforcement.

Based on these results, it can be concluded that the pressure beam used is safe against cracking moments, shear forces and deflection for use in planning.

Keywords— structure, presstres beam, stress