SCAFFOLDS AND LADDERS 1. General provisions 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. Scaffolds should be provided with safe means of … Read more
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 Analyse water for its chemical compositions as per IS 3025-1964 and compare these with permissible limits given in IS: 456-2000. In case water does not … Read more
Earth 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 borings to … Read more
FACTORS AFFECTING CHOICE OF CONCRETE FOR A STRUCTURE The choice of whether a structure should be built of concrete, steel, masonry, or timber depends on the availability of materials and on a number of value decisions. 1. Economy Frequently, the foremost consideration is the overall cost of the structure. This is, of course, a function … Read more
Portland Pozzolana Cement 1. Pozzolana Pozzolana is a volcanic powder found in Italy near Vesuvius A pozzolanic material is essentially a siliceous or aluminous material which possess no cementitious properties. But it has the property when it combined with lime to produce a stable pozzolana compound it has definite cementitious properties. In the presence of … Read more
DAMPNESS PREVENTION METHODS: The following are the precautions to be taken to prevent dampness in buildings, before applying the various techniques. The site should be located on high ground and well-drained soil to safe guard against foundation dampness All the exposed walls should be of sufficient thickness to safeguard against rain protection (minimum 30 cm) … Read more
PLASTERING The following topics are covered in this post. What is plastering? What are the requirements of good plaster? Different types of mortars for plastering Number of coats of plastering How to preparation of background before plastering? What are the recommended mortars mixes for different situation? What are the defects in plastering? What is plastering? … Read more
TYPES OF DEFECTS IN PLASTER This post describes 7 different categories of defects most frequently noticed in plaster (as mentioned below) Non-structural cracks Structural cracks Debonding Lack of hardness Grinning Expansion Popping The causes and repair methods for each are discussed below. 1. Non-structural cracks Crazing is a network of fine cracks, usually in a … Read more
AIR ENTRAINED CONCRETE A major advance in concrete technology in recent years is the introduction of tiny disconnected air bubbles into concrete called air entrainment. Air entrained concrete results from using either an air-entraining cement or an air-entraining admixture during mixing. Adding entrained air to concrete provides important benefits in both plastic and hardened concrete, … Read more
Requirements of Good Stairs A good stair should provide an easy, quick and safe mode of communication between the various floors of the building. General requirements of good stairs are as mentioned below. 1. Location It should preferably be located centrally, ensuring sufficient light and ventilation. 2. Width of Stair The width of stairs for … Read more