A Brief Review on Seismic And Cracks

Cracking is one of the major challenge faced by Civil Engineer Cracking in structures is common occurrence and engineers are often required to look into their causes and to carry out suitable repairs and remedial measures. For repairs and remedies to be effective, it is essential that the engineer should have proper understanding of various causes of cracking. For investigating the causes it is necessary to observe carefully location, shape, size, depth, behavior and other characteristics of the cracks, and to collect information about specifications of the job, time of construction and past history of the structure. It will also be necessary for the engineer to know as to when the cracks first came to notice and whether the cracks are structural or non-structural. Structural cracks are those which are due to incorrect design, faulty construction, poor workmanship, Poor Quality & Material, overloading and these may endanger the safety of a building. Non-structural cracks which are due to moisture changes, thermal variations, elastic deformation, creep, chemical reaction, foundation movement and settlement of soil, vegetation, etc. Non-structural cracks are mostly due to internally induced stresses in building materials and these generally do not directly result in structural weakening. In course of time however, sometimes these cracks may, because of penetration of moisture through cracks or weathering action, result in corrosion of reinforcement and thus may render the structure unsafe. In order to be able to prevent or to minimize occurrence of cracks, it is necessary to understand basic causes of cracking and to have knowledge about certain properties of building materials, specification for mortar and concrete, Architectural design of building, structural design, foundation design, construction practices & techniques and environments.