Impact Of High Temperature On Different Combinations Of Fiber Reinforced Concrete.pdf

Impact of high temperature on different combinations

of fiber reinforced concrete

S.Peskova* and P. P. Prochazka

*Czech Technical University, Civil Engineering, Thakurova 7, 166 29 Prague, Czech Republic

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Abstract:

Fire belongs to one of the most dangerous aspects of civil and underground engineering, mainly in the assessment  of  underground structures. The extensive use of concrete as structural materials of linings or envelopes of underground power stations has led to the need of full understanding the effects of fire. If concrete is subject to high temperature, its mechanical behavior, including the compressive and tensile strengths, Poisson’s ratio and modulus of elasticity, etc. ,changes dramatically with the increase  of  temperature. On  the other hand, these changes depend also on the peak temperature, the rate  of heating, the fire duration (time at which the structure is exposed to the extreme temperature), on the type of concrete and the type of testing. The distribution of temperature inside of the concrete slabs (cubes) reveals to be a very important phenomenon, as the water inside there changes at a special temperature to a vapor, which,as superheated, can damage the surface of the concrete elements and lower their bearing capacity. A large scale of experiments has been carried out, which can, a. o., serve a possible improvement of the formulation of material properties and subsequent comparison with numerical results. Various combinations of fibers, such as a compound of PP and steel, also a carbon and steel combination and the normal concrete have been tested for temperature to 10000 C. Cubes with dimension of 7x7x7cm3 serve as the test specimens, which are heated to Moneygram agent 150, 500, 600 or 10000 C. This dimensionis in full compliance with the existing norms. The loading is due to a one-sided heating, while the other sides of the cubes will be held at room temperature.