Pengaruh fireproofing pada perilaku pelat beton normal dengan tulangan mutu tinggi

BUSRONI, Latif, Ir. HRC. Priyosulistyo, MSc.,PhD

2003 | Tesis | S2 Teknik Sipil

Struktur pelat dengan tulangan mutu tinggi wire niesli yang terbakar, dapat tidak mampu mendukung beban rencana yang disebabkan luasnya bidang kontak api terhadap esposc'd s14~fuc.e. Antisipasi yang dapat dilakukan antara lain penggunaan lapisan ,fireproofing untuk inengurangi rambatan panas. Pemahaman yang baik tentang distribusi temperatur, kekuatan, perilaku, respon dan pola keruntuhan struktur serta efektifitas penggunaan jireproofkg sangat diperlukan, untuk ineinperoleh desain yang aman. Dalam penelitian ini digunakan seinbilan benda uji pelat beton ukuran 150 cni M 60 cm x 6 cm (panjang x lebar x tebal), dengan beton inutu normal yang mempunyai kuat tekan 26 MPa dan tulangan mutu tinggi dengan diameter 3,9 mm ysng memiliki kuat leleh 600 MPa. Variasi jenis jireproclfing, yaitu: pertebalan seliinut beton, plesteran mortar beton, dan ,fireproofing pabrikasi. Pembakaran disesuaikan dengan kurva standar ASTM E- 1 19 untuk ketahan 2 jam dan dibebani beban rencana yang tereduksi sesuai kondisi kebakaran. Hasil penelitian meniinjukkan bahwa distribusi teinperatitr dari esposed nszit,*fi/cc bagian dalam pelat membentuk garis lengkung exponential yang ke seinakin inenyeinpit pada kedalainan yang cukup untuk inengisolasi temperatur. t)eileksi pelat beton bertambah seiring dengan durasi pembakaran dan peningkatan temperatur, dan bertambah besar pada temperatur di atas 300°C. Pelat yang terbakar selama 30 inenit dengan temperatur inaksimum 71 6°C inengalami detleksi sebesar 137% dari batas 1J360 dan kuat lentur turun menjadi 92%, kuat tekan beton esposed szufiiw turun menjadi 79,5%, sedangkan kuat leleh baja turun men-jadi 91%, dan keruntuhan lentur pelat meneruskan retak rambut akibat liehaliaran. /<'ireproofing pertebal selimut beton mereduksi temperatur hingga 40% dan mereduksi defleksi hingga 45%. /+'ireproofing plesteran mortar beton inereduksi temperatur hingga 47%, mereduksi defleksi hingga 36010, dan ineningkatkan kuat lentur pasca kebakaran hingga 106%. /+'ireproofing pabrikasi mereduksi temperatur hingga 65%, mereduksi defleksi hingga 92%, dan meningkatkan kuat lentur pasca kebakaran hingga 104%, bentuk ~jireproofi'ng yang paling efektif adalah,fire/,roo~lngpabrikasi.

Reinforced concrete slabs using high strength wire steel could be unsatisfying due to the high temperature and the area of exposed surface when is burned down. One of several efforts on delaying heat transfer is done by covering the exposed surface using fireproofing material. On that way, it is important to understand the physical properties such as strength, behavior and heat transfer resistant of fireprooting material in order to comply with code of practice. Nine specimen of reinforced concrete slab were designed and arranged. Each sample has dimension of 150cm x 6Ocm x 6cm (length x breadth x thickness), having compressive strengh of 26 MPa with the steel wire reinforcement was of 39mm diameter and yield stress of 600 MPa. The concrete cover was made varied in four types, e.i: the standard loinin concrete cover, 20mm concrete cover, lOmm concrete cover+lO mm plaster mortar, and lOmm -concrete cover+ 1O m m fabricated fireproofing. The standard heat curve of ASTM E-119 for 2 hours was adopted. The test results showed that the temperature distribution can be expressed as an exponential curve, which goes down and became asymptotic with the depth of the concrete. The specimen was burned for 30 minutes with maximum temperature of 716°C result in the detlection o f 137% bigger than the maximum limit (L/360). The flexural strength and the compression strength of concrete decreased to 93% and 7 0 3 6 while the yicld stress o f reinforcing \\ire decreased to 9 1%. Crack pattern about the flexural load continued the previous crack due to the fire. The addition of concrete co\,er reduced further the temperature and the deflection to 4096 and 45% respectivcly. The standard concrete cover with addition of plaster mortar reduced furthcr the tcmperature and the deflection to 47% and 36% respectively but increased the post burning flexural strength up to 106°/0. The standard concrete cover i\.ith addition of fabricated fireproofing reduced further the temperature and the detlection to 65% and 92% respectively but increased the post burning flexural strength up to 1049’0.It concluded that thc concrete cover with addition of fabricated fireproofing material will be the most effective effort on delaying heat transfer on the slab.

Kata Kunci : Plat Beton,Tulangan Mutu Tinggi,Fireproofing