Joints in concrete structures such as contraction joints and expansion joints are required to be provided to prevent cracks in concrete at hardened state. To provide these joints, there certain specification which must be followed. These specifications are explained below: Specifications for Construction joints: A construction joint is defined as a joint in the concrete(…)
STRUCTURAL USES OF PRECAST CONCRETE
Precast concrete is used extensively in building structures, for e.g. structural frames, floors and roofs, claddings etc. Use of Precast Concrete in frames: There are two main types of precast building frame. The structural frame consists of slabs, beams and columns. Structural frames are mainly used for offices, car parks and retail developments. The cross-wall(…)
SELF COMPACTING CONCRETE MIX DESIGN REQUIREMENTS
MIX DESIGN OF SELF COMPACTING CONCRETE (SCC) Self Compacting Concrete has to be designed and tested before it is produced and used for construction. During SCC evaluation, the local materials and equipments have to be tested to find out the right concrete mix proportions and mixing times suitable for the element to be cast. Various(…)
TYPES OF CONSTRUCTION COST ESTIMATES
Types of Construction Cost Estimates Construction cost constitutes only a fraction, though a substantial fraction, of the total project cost. However, it is the part of the cost under the control of the construction project manager. The required levels of accuracy of construction cost estimates vary at different stages of project development, ranging from ball(…)
CRITERIA FOR DESIGN OF EARTH DAMS
The criteria for the design of earth dams are: 1. Sufficient spillway capacity and freeboard are provided so that there is no danger of overtopping of the dam 2. Seepage flow through the embankment is controlled so that the amount lost does not interfere with the objective of the dam and there is no erosion(…)
EARTHFILL DAMS & ITS CLASSIFICATION
Earthfill dams are the most common type of dam built to any height. They are designed as a non-overflow section with separate spillway. The reason for such wide spread use of earthfill dams are: The foundation requirements are not as rigorous as other dams Local available soil is the main construction material High skill not(…)
PROSPECTS & USES OF PLASTICS IN BUILDINGS
There are two types of Plastics, namely Thermoplastic and Thermosetting plastics distinguished by the physical property. Thermoplastics: This type can be softened by heating after they have been cured and remoulding cycle can in theory be repeated an indefinite number of times but in practice some defects may eventually take place. The curing process is(…)
COMMON STRUCTURAL FAILURE CAUSES
Many decisions in design are based on engineering judgement, but not only on the understanding of theory or any computational tools. Even experience in extensive design in academic context can provide only limited perspective in engineering decision making. Most lessons in engineering decision making come from the cases of histories of failures of structures, which(…)