Steel Box Girders Steel box girders are usually adopted in very long span bridges where it is necessary to keep the self-weight of the structure as minimum as possible. Depending on the width requirements single and multiple cell girders are selected. Steel Box girders are used for footbridges curved in plan and also for bridges … Read more
Pile Foundation Pile Foundation. Pile foundations are deep foundations used when the site has a weak shallow bearing strata making it necessary to transfer load to a deeper strata either by friction or end bearing principles. Foundations provide support for structures by transferring the load to the rock or layers of soil that have sufficient … Read more
Sprayed Concrete for Repair of Structures Sprayed concrete can be defined as mortar or concrete pneumatically projected into place’. Sprayed concrete is used widely in the repair of deteriorated structures, because of its ease of application in situations where it is virtually impossible to use formwork to recast, and because it can be applied in … Read more
Failure Modes Introduction Slope failures are essentially natural hazards that occur in many areas over the world. Popularly known as landslides, slope failures describe a wide variety of mechanisms that cause the outward or downward movement of slope-forming materials like rock, soil or landfills. Landslide can result either from rock failure or soil failure. While … Read more
Underwater Construction Underwater construction is a method on how to place the concrete underwater. During the construction of bridges, dams or any structure where the foundation is most likely to lie underwater, the underwater construction is opted. Construction in water poses many difficulties especially in the places where the depth is considerable. During underwater construction, … Read more
Limitations of Reinforced Concrete without Prestressing Dead loads, imposed loads, deformations and load-independent effects such as temperature changes and shrinkage induces tensile forces in a RC beam. Since the tensile strength of concrete is low steel reinforcement bars are embedded in the concrete to carry all internal tensile forces. Prestressed concrete is an advanced form … Read more
Introduction to Artificial islands An artificial island is an island constructed by man rather than created by natural means. They are constructed by expanding the existing islets and by construction on existing reefs or merging some natural islets into a bigger island. Artificial islands are usually constructed by land reclamation. Land reclamation is a process … Read more
Curing of Concrete Curing of Concrete is a method by which the concrete is protected against loss of moisture required for hydration and kept within the recommended temperature range. Curing will increase the strength and decrease the permeability of hardened concrete. Curing is also helps in mitigating thermal and plastic cracks, which can severely impact durability of structures. A curing practice involves keeping the concrete damp or moist until the hydration of concrete is … Read more
What is Bleeding in Concrete? Excessive displacement of water by solids in fresh concrete mixture, after the compaction process is called Bleeding in Concrete. Concrete in fresh state is a suspension of solids (aggregates and cement) in water, and after compaction there is a tendency for the solids to settle. This sedimentation displaces the water … Read more