Alternative ways of reinforcing cement composites
Agnieszka Ślosarczyk, Józef Jasiczak
Quarterly No. 4, 2012 pages 266-271
DOI:
keywords: fibres reinforced concrete, short steel fibres, short polypropylene fibres, steel rods, the mechanical properties, the load-carrying ability
abstract This paper presents the results of laboratory research on concrete beams with alternative types of reinforcement, assuming a constant volume of fibers. As the reinforcement of the cement matrix, two types of macro-fibres, namely steel and polypropylene fibres, were used. In addition, traditional beam reinforcement in the form of aligned, smooth, and ribbed steel rods were tested. In the case of the long fibers-the steel bars were assumed to force the long fibers to adopt a certain position – four rods at the corners of the cross section, two of which were in the tension zone and two in the compression zone. By introducing a slip sleeve in three stirrups to stabilize the transverse bars in the desired position, efforts were made to ensure the independent operation of each of the four rods. It was shown that the highest load-carrying capacity and the toughness of the composite, was obtained for concrete beams reinforced with ribbed steel rods. Unexpectedly, the beams with the polypropylene fi bers and smooth steel rods showed substantial susceptibility to deflection. In both cases good interaction between the reinforcement and cement matrix was observed. The fracture toughness of the reinforced concrete and steel synthetic macrofibres in the share volume was comparable to 1.65% as documented by an equivalent flexural strength.