Comparative study on Steel fibre reinforced Cum control concrete under flexural and deflection
Fibre reinforced concrete, a composition of concrete and fibres is being prominently used for various important applications. The hook tain steel fibres assist in controlling the propagation of micro-cracks present in the matrix, first by improving the overall cracking resistance the matrix and later by bridging across even smaller cracks formed after the application of load on to the member thereby preventing there widening into major cracks. In the present paper, the effect of steel fibre reinforcement with different percentage of fibre 0, 1%, 2% and 3% by volume for M-40 grade of concrete with aspect ratio 50, 60 and 67 are studied. The beam is tested for flexural strength. The percentage increase through utilization of steel fibers is reported. A relationship between aspect ratio vs. flexural strength represented graphically.
BAMBOO: FUNCTIONALLY GRADED COMPOSITE MATERIAL
The bamboo structure can be generally viewed as a Functionally Graded composite material constituted by long and aligned cellulose fibres embedded in a lignin matrix. Analysing the transversal section of a bamboo culm, one can observe that the fibre distribution is variable through its thickness. The non-uniform distribution of fibres prevents the direct application of equations used to model the behaviour of composite materials, as the rule of mixtures equations for strength and modulus of elasticity. These equations assume, besides the perfect bonding between fibre and matrix, uniform distribution of the fibres in the matrix. In bamboo, the fibre distribution follows an organized pattern with a higher concentration of fibres on the outer surface of the culm. Establishing how this variation occurs, the basic equations from the composite materials approach can be modified in order to model the mechanical behaviour of bamboo. This paper presents the meso-structure analyses of bamboo culms through Digital Image Analysis. The variation of the volume fraction of the cellulose fibres across the transversal section of the bamboo is established. The developed methodology is successfully applied to study the volume fraction variation of fibres in two different samples of bamboo species Phyllostachys heterocycla pubenscens, commonly know as “Moso”.
APPLICATION OF SATELLITE PHOTOGRAPHS IN A MORPHOTECTONIC STUDY OF THE CENTRAL ALBORZ, IRAN
This paper introduces a study of morphotectoni c structure in the Central Alborz Basin, Mazandaran province of Iran (about 1200 square kilometer), using Russian KFA-1000 satellite photography and sequential air photographs. The KFA-1000 metric camera has better ground resolution than SPOT and LANDSAT for the whole of the study area. Results are provided from one pair of 30×30 cm. photos, which provided easy interpretation and better results than other data. Areas identified from these images as being of significance were examined in greater detail through the use of aerial photographs (at scales of 1:5000, 1:10000 and 1:60000 were available).