Earth Excavation Checklist excavation checklist The following checklist should be used as a guide for better quality control over earth excavation. (1) Prior to the start of excavation operations, take photographs of the construction area, make sure that sufficient cross—sections are taken, and continue to take progress photographs during construction. (2) Review the log of…
Suitability Of Water For Concrete Mixing OBJECTIVE To assess suitability of water for use in concrete mix. EQUIPMENT § Measuring cylinder § Cube moulds § Trowel § Tamping rod § Vibrating table § Testing machine PROCEDURE 1. Analyse water for its chemical compositions as per IS 3025-1964 and compare these with permissible limits given in IS: 456-2000. 2. In case water does not satisfy the permissible limits or…
Scaffolds and ladders 1. GENERAL PROVISIONS 1. Where work cannot safely be done on or from the ground or from part of a building or other permanent structure, a safe and suitable scaffold should be provided and maintained or other equally safe and suitable provision should be made. 2. Scaffolds should be provided with safe means of access,…
In RC buildings, portions of columns that are common to beams at their intersections are called beam-column joints (Figure 1). Since their constituent materials have limited strengths, the joints have limited force carrying capacity. When forces larger than these are applied during earthquakes, joints are severely damaged. Repairing damaged joints is difficult, and so damage…
Determine splitting tensile strength of cylindrical concrete specimens OBJECTIVE: This method covers the determination of the splitting tensile strength of cylindrical concrete specimens Theory: Age at Test – Tests shall be made at recognized ages of the test specimens, the most usual being 7 and 28 days. Where it may be necessary to obtain the early strengths,…
Types of loads External loads on a structure may be classified in several different ways. In one classification, they may be considered as static or dynamic. 1. Static loads are forces that are applied slowly and then remain nearly constant. 2. One example is the weight, or dead load, of a floor or roof system. 3. Dynamic loads vary with…
1. Pig iron The crude impure iron, which is extracted from iron ores, is known as pig-iron and it forms the basic material for the manufacture of cast-iron, wrought iron and steel. The pig iron is manufactured by the following operations (i) Dressing: Crushed into pieces 25mm, impurities of clay, loam and other earthy matter removed…
Types of defects in timber Types of Defects in timber are grouped into the following divisions. 1. DEFECTS DUE TO CONVERSION During the process of converting timber to commercial form, the following defects may occur. § Chip mark: mark or sign placed by chip on finished surface of timber § Diagonal grain: Due to improper sawing of timber § Torn grain: Due…
Properties of mortar Properties of mortar which are sought for use in masonry are: workability, water retentivity, rate of stiffening, strength, resistance to rain penetration and durability. These properties have been discussed below explaining their effect on masonry. Choice of masonry mortar is governed by several considerations such as § Type of masonry unit and its…
REQUIREMENTS OF FORMWORK Requirements of formwork – quality, safety & economy In the selection of materials for formwork, the three general principles of quality, safety and economy must be paramount. Material quality can ensure safety, and significantly contributes to the achievement of economy. Formwork failure can result in loss of life and always causes catastrophic financial loss. Some general guidelines can…