Shear Predictions of Eurocode EC2
The shear strength of reinforced concrete members is a function of shear capacity of concrete (Vc), which in turn depends on influencing parameters including concrete compressive strength (f’c), ratio of tension reinforcement (), shear span to depth ratio (a/d), size effect or depth factor (ξ), size of the aggregate in relation to the minimum size of the member (aggregate interlock aspects).Over the last several decades, researchers have tested reinforced concrete beams (without web reinforcement) over a range of variables limited by the breadth and depth of their experimental investigations and on the basis of their experimental results, have proposed empirical equations for predicting the shear capacity of normal and high strength-high performance concrete in reinforced concrete beams. In this paper a relational database using ACCESS software is developed and is populated with experimental results of 2145 shear critical reinforced concrete beams without web reinforcement using both normal as well as high strength –high performance concrete. An evaluation was also conducted to assess the predictive accuracy of shear design equation of Euro Code EC2. The results indicate for beams of normal as well as high strength concrete, the Euro Code EC2 design equation is adequate to accurately predict the shear capacity of reinforced concrete beams over the range of variables considered in this study.
Evaluation of Shear Strength of High Strength Concrete Beams
The book is recommended for the research graduate students perusing their research in the fields of high performance and high strength concrete with special reference to shear properties. The findings of the research can also be used by the graduate students interested in the in-depth analysis of Building Codes provisions of High Strength and High Performance Concrete. The book is recommended for use of the students interested to study the behavior of High Strength Concrete beams as well. The book involves analytical study of the high strength concrete beams on the basis of various parameters such as longitudinal steel ratio, shear span to depth ratio, web reinforcement etc. The contribution of web steel to the shear capacity of the beams has also been analyzed. 70 beams have been tested to verify these parameters. The results of the shear capacity of the high strength concrete beams have been compared with the provisions of the various building and bridges codes, most commonly practiced by the designers and engineers of concrete structures. The study of disturbed region in concrete structures provides the basic knowledge for the detailed research by the interested students....
New approach to vision-based BGA package inspection
Ball grid array (BGA) techniques have developed very fast due to the advantages of more I/O ports, small size, and so on. In this paper, a vision-based algorithm for BGA package inspection is proposed to accurately estimate center and diameters of solder-balls of BGA packages, so that defects of BGA packages, such as missing or extra balls, oversize or undersize balls, over-height or under-height balls, and pitch can be detected for ensuring the quality of BGA packages.