The Civil Engineering website
Structural dynamics and earthquake engineering 1. Define the concept of dynamic degree of freedom. Give some examples of single degree of freedom systems and multi degree of freedom systems. Answer: Dynamic degrees of freedom are a set of independent displacements/rotations that completely define the displaced position of the mass with respect to its initial position. … Read more
Causes, Evaluation and Repair of Cracks in Concrete Cracks in concrete have many causes. They may affect appearance only, or they may indicate significant structural distress or a lack of durability. Cracks may represent the total extent of the damage or they may point to the problems of greater magnitude. Their significance depends on the … Read more
Unbonded Post-Tensioning System Technology in Building Construction Introduction During the last three decades, unbonded post-tensioning has progressively become the predominant construction choice for commercial concrete buildings in the United States. The utilization of unbonded tendons is now standard practice for concrete structures. Because of their excellent performance record and their economical and versatile application, the … Read more
Fiber-Reinforced Concrete Historical Development Fibers have been used to reinforce brittle materials from time immemorial, dating back to the Egyptian and Babylonian eras, if not earlier. Straws were used to reinforce sun-baked bricks and mud-hut walls, horse hair was used to reinforce plaster, and asbestos fibers have been used to reinforce Portland cement mortars. Research … Read more
Concrete Basics & The need for Joints What Causes Concrete To Crack? Many surface cracks in concrete slabs are not a result of structural failure of the slab but are formed by uncontrolled shrinkage of the concrete. These types of cracks can be avoided. Shrinkage cracks are the result of the concrete volume decreasing as … Read more
Aci Method Of Concrete Mix Design: A Parametric Study ABSTRACT: Concrete mix design by the ACI method requires various material properties as the input. The effect of variation of these input parameters on mix proportions has been studied here, with reference to strength attainment in few cases. The sensitivity of the mix has been expressed … Read more