Defects in brickwork EFFECTS OF WORKMANSHIP ON MASONRY STRENGTH Masonry has a very long tradition of building by craftsmen, without engineering supervision of the kind applied to reinforced concrete construction. Consequently, it is frequently regarded with some suspicion as a structural material and carries very much higher safety factors than concrete. There is, of course,…

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,…

PLASTERING                        plastering The following topics are covered in this post. 1.      What is plastering? 2.      What are the requirements of good plaster? 3.      Different types of mortars for plastering 4.      Number of coats of plastering 5.      How to preparation of background before plastering? 6.      What are the recommended mortars mixes for different situation? 7.      What are the defects in plastering? WHAT IS…

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 of…

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…