Carbon fiber reinforced plastic (CFRP) composites have been extensively used in fabrication of primary structures for aerospace, automobile and other engineering applications. With continuous and widespread use of these composites in several advanced technology, the frequency of failures is likely to increase. Therefore, to establish the reasons for failures, the fracture modes should be understood thoroughly and unambiguously. In this paper, CFRP composite have been tested in tension, compression and flexural loadings; and microscopic study with the aid of Scanning Electron Microscope (SEM) has been performed on failed (fractured) composite surfaces to identify the principle features of failure. Efforts have been made in correlating the fracture surface characteristics to the failure mode. The micro-mechanics analysis of failure serves as a useful guide in selecting constituent materials and designing composites from the failure behavior point of view. Also, the local failure initiation results obtained here has been reliably extended to global failure prediction.

This paper studies the development of hybrid fibre reinforced self-compacting concrete as per Nan Su criteria. Results predicted that various packing factors adopted in the study are 1.12, 1.14, 1.16 and 1.18. Fine aggregate /Total aggregate ratios (s/a ratio) adopted in the study are 0.5, 0.53 and 0.57. The optimum combinations of packing factor and s/a ratio are found to be 1.12 & 0.53 and 1.14 & 0.57 for M30 grade SCC mixes because these optimum PF and s/a ratio combination gives comparatively better particle packing density in SCC mixes. Better particle packing density enhances the microstructure of SCC mix subsequently more strength and durability can be achieved. As PF increases powder content decreases and aggregate content increases requiring more paste to make the SCC mix workable. Less value PF will have high particle packing density yielding more strength due to improved microstructure of SCC mixes. At PF & s/a combinations of 1.12 & 0.53 and 1.14 & 0.57, the workability of SCC mixes is superior because of high paste volume and less aggregate content. Compressive, split-tensile and flexural of M30 grade SCC mixes made with optimum combinations of packing factor and s/a ratios are found to be high.

In this paper, the flexural behaviour of M30 grade basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars are studied and compared with slabs made with steel rebars. The optimum percentage of basalt is 0.3% for 50mm length basalt fibres. Due to high particle packing density in concrete made with basalt fibre micro cracks are prevented due to enhanced fatigue and stress dissipation capacity. Addition of basalt fibres to enhances the energy absorbtion capacity or toughness thereby enhancing the resistance to local damage and spalling. Addition of basalt fibres controlled the crack growth and crack width. Load at first crack of M30 grade basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars is more than M30 grade conventional concrete slabs made with steel rebars because the with addition of basalt and BFRP bars will make either the interfacial transition zone (ITZ) strong or due to bond strength of concrete slabs made with basalt fibre reinforced polymer rebars. The ultimate strength in M30 grade basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars is more than conventional concrete slabs made with steel rebars. Deflection at the centre of M30 grade basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars is almost double than the conventional concrete slabs made with steel rebars. Toughness indices evaluated for M30 grade basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars indicates that basalt fibre and BFRP bars will enhance the energy absorbtion capacity of slabs.

The aim of this study is to determine the stress-strain behavior of basalt fibred concrete experimentally. Cylinders of standard size 150 x 300 mm are cast with with and without basalt fibres and tested in uni-axial compression under strain control as per IS: 516-1999 to understand the stress-strain behavior of basalt fibred concrete. After developing empirical equations for stress-strain curves of basalt fibred concrete, theoretical values of stresses are calculated at different values of strains in concrete based on the developed empirical equations as given above and theoretical stress-strain curves are plotted. These theoretical stress-strain curves are compared with experimental stress-strain curves and found that, theoretical stress-strain curves have shown good correlation with experimental stress-strain curves for all concrete mixes.