Pengaruh Fireproofing Pada Perilaku Pelat Beton Normal Dengan Tulangan Mutu Tinggi = The Effect of Fireproofing on the Behavior of Reinforced Concrete Slabs Using High Strength Steel Wire

Reinforced concrete slabs using high strength steel wire could be unsatisfying under high temperature due to the larger surface area of exposed concrete in comparison to other structural elements. One of several efforts on delaying heat transfer is done by applying extra cover to the concrete surface using fireproofing material. On that way, it is important to study the physical properties, such as strength behavior and heat transfer resistant of fireproofing material in order to comply with the code of practice. Nine specimens of reinforced concrete slab were designed and arranged. Each sample had dimension of 120 cm x 60 cm x 6 cm (length x breadth x thick), a compressive strength of 26 MPa, with the steel wire reinforcement of 39 mm diameter and the yield stress of 600 MPa. The concrete cover varied in four types, e.i: the standard 10 mm concrete cover, 20 min concrete cover, 10 mm concrete cover+10 mm plaster, and 10 mm concrete cover+l0 mm fabricated fireproofing. The standard heat curve of ASTM E-119 for 2 hours was adopted. The test results showed that the temperature distribution could be expressed as an exponential curve, which went down and became asymptotic with the depth of the concrete. The specimens, which was exposed to fire for 30 minutes with maximum temperature of 716°C, resulted in the deflection of 137% bigger than the maximum limit (L/360). ⢠The flexural strength and the compressive strength of concrete decreased to 92% and 79,5%, respectively, while the yield stress of reinforcing wire decreased to 91%. Crack pattern about the flexural load continued the previous crack during fire expose. The addition of concrete cover reduced further the temperature and the deflection to 40% and 45% respectively. The standard concrete cover with addition of plaster reduced further the temperature and the deflection to 47% and 36% respectively but increased the flexural strength after fire expose up to 106%. The standard concrete cover with addition of fabricated fireproofing reduced further the temperature and the deflection to 65% and 92% respectively but increased the flexural strength after fire expose up to 104%. It could be concluded that the concrete cover with addition of fabricated fireproofing material will be the most effective effort on delaying heat transfer on the slab. Keywords : fireproofing, concrete cover, exposed concrete, heat transfer