EFFECTS OF TYPE OF CEMENT AND AGGREGATE ON THE DEGRADATION OF CONCRETE EXPOSED TO SUSTAINED TEMPERATURES UP TO 300 °C

Author(s): Hideo Kasami,Hironobu Nishi,Toshinobu Maenaka and Yoshitaka Ichihara
Paper category: Proceedings
Book title: Proceedings of CONSEC13 Seventh International Conference on Concrete under Severe Conditions - Environment and Loading Volume I
Editor(s): Z.J. Li, W. Sun, C.W. Miao, K.Sakai, O.E. Gjørv, N.Banthia
ISBN: 978-2-35158-124-7
e-ISBN: 978-2-35158-134-6
Publisher: RILEM Publications SARL
Publication year: 2013
Pages: 837-850
Total Pages: 961
Language : English

Abstract: This paper presents the results of experimental study on the effects of cement type and conditions for curing exposure up to 300°C.Specimens made of 5 mixture of concrete containing 4 type cements and 2 kinds aggregates were tested for weight loss,compressive strength,modulus of elassticity,powder X-ray diffraction and pore size distribution after sustained exposure to temperatures up to 300°C with and without seal for 91days. Concrete properties were much affected with cement and aggregate types and exposure conditions besides exposure temperatures.Weight loss was lower up-to 80°C for expsure with seal than for without seal.Residual compressive strength and modulus of elasticity were higher for exposure with seal than for without seal. Consequently,residual strengths were higher for the same weight loss.Residual strengths were lower for concrete containing BB cement,showing minimal point at 50°C with 20% reduction,and those containing NP and MP showed minimal at 80°C, while those containing FB did not show minimal point. The X-ray diffraction pattern showed distinction of AFt(Etringite) and Calcium Alminate at higher temperature. Pore size distribution indicated remakable increase of pore volume finer than 0.1 μm in radii with temperature rize from 20°C to 50°C and pore volume of larager than 0.1μm in radii with rize from 110 to 300°C due to evaporation of physically bound water or breakdown of gels, which would be the cause of strength loss with temperature.

Online publication : 2013
Publication type : full_text
Public price (Euros) : 0.00