numero26

A. Namdar et alii, Frattura ed Integrità Strutturale, 26 (2013) 22-30 ; DOI: 10.3221/IGF-ESIS.26.03 23 E XPERIMENTAL SET - UP he small steel fiber has been mixed with plain concrete. The beam B1 made with100 mm × 100 mm ×500 mm dimensions. Length of small steel fiber 10 mm, 20 mm, 30 mm, 40 mm and 50 mm has been varied. The quantity of small steel fiber 0.5% and 1% weight of concrete has been selected (Fig. 1-2). Figure 1 : Beam B1, steel fiber shown in surface of beam. Figure 2 : Steel fiber. P REPARATION PROCEDURE OF SPECIMENS rdinary Portland Cement (OPC), sand, coarse aggregate and water have been used for casting plain concrete. Small smooth steel fiber of 0.5% & 1.0% has been mixed with plain concrete (Fig. 2-3 and Tab. 1). After curing the flexural strength and crack morphology of concrete beams have been investigated. The plain concrete cube with dimensions of 100 (mm) × 100 (mm) × 100 (mm) has been made and tested, the results show 28.51 (N/mm 2 ) stress and strain of 0.01488 %, this is as predicted during the design stage (Fig. 4-5). The plain concrete has been designed for sustain stress of 40 (N/mm 2 ) on 28 days. The compressive strength of specimen reached to 70% of design on 14 days. The result is acceptable according to ACI standard. Figure 3 : Basic materials of concrete. T O