%0 Journal Article
%T Experimental and Numerical Evaluation of Direct Tension Test for Cylindrical Concrete Specimens
%A Jung J. Kim
%A Mahmoud Reda Taha
%J Advances in Civil Engineering
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/156926
%X Concrete cracking strength can be defined as the tensile strength of concrete subjected to pure tension stress. However, as it is difficult to apply direct tension load to concrete specimens, concrete cracking is usually quantified by the modulus of rupture for flexural members. In this study, a new direct tension test setup for cylindrical specimens (101.6£żmm in diameter and 203.2£żmm in height) similar to those used in compression test is developed. Double steel plates are used to obtain uniform stress distributions. Finite element analysis for the proposed test setup is conducted. The uniformity of the stress distribution along the cylindrical specimen is examined and compared with rectangular cross section. Fuzzy image pattern recognition method is used to assess stress uniformity along the specimen. Moreover, the probability of cracking at different locations along the specimen is evaluated using probabilistic finite element analysis. The experimental and numerical results of the cracking location showed that gravity effect on fresh concrete during setting time might affect the distribution of concrete cracking strength along the height of the structural elements. 1. Introduction Concrete cracking strength is difficult to be quantified and therefore is a source of considerable uncertainty in serviceability prediction. The existence of cracks under service load in reinforced concrete (RC) structures makes it difficult to predict deflections. While cracked concrete is usually assumed to be incapable of carrying tensile stresses, the concrete between adjacent cracks can resist tensile force due to the bond between concrete and steel reinforcement. This is known as tension stiffening effect. Therefore, for the consideration of the deflections of RC structures, concrete cracking strength affects the structural stiffness of the members. Moreover, cracking plays an important role in the durability of RC structures. When concrete cracks, its permeability increases and the processes of concrete deterioration and rebar corrosion get accelerated [1, 2]. For flexural elements, concrete cracking is usually represented by the modulus of rupture [3]. However, in research experiments, the modulus of rupture showed a wide variation [4, 5]. While the modulus of rupture provides a good estimate for cracking strength, researchers showed that accurate serviceability predictions require obtaining the real tensile strength of concrete [6]. Moreover, researchers have argued that, because of the significance of shrinkage on serviceability of RC structures, other cracking
%U http://www.hindawi.com/journals/ace/2014/156926/