PROPERTIES OF HARDENED CONCRETE The following are the properties of concrete in its hardened state, used by the designer during design process of reinforced concrete structure. 1. Compressive Strength The characteristics strength is defined as the strength of concrete below which not more than 5% of the test results are expected to fall. As per … Read more
Design Procedures for a Building Foundation (Step by Step) Good design must not only be safe but must aim to save construction costs, time and materials. The following procedures should help to achieve this and an ‘educated’ client will recognize the importance of funding this work with a realistic fee. 1. Decide the Location of … Read more
PRACTICAL PROBLEMS TO KEEP IN MIND BEFORE FOUNDATION DESIGN There are, in foundation design, a number of practical construction problems and costs to be considered. The chief ones are: The foundations should be kept as shallow as possible, commensurate with climatic effects on, and strength of, the surface soil; particularly in waterlogged ground. Excavation in … Read more
Bulking of Sand – What, Why & How? After watching this video you will be able to answer following questions. What is bulking of sand? Why bulking happens? What are the factors affecting bulking of sand? How to measure bulking of sand at site? What are the effects of bulking on concrete? How to apply … Read more
Properties of Aggregates Approximately 75% of the volume of concrete is occupied by aggregates, so quality of aggregates plays an important role in determining properties of concrete. Aggregates are chemically inert, solid bodies held together by the cement. Aggregates come in various shapes, sizes, and materials ranging from fine particles of sand to large, coarse … Read more
FIRE RESISTING PROPERTIES OF COMMON BUILDING MTERIALS Fire resisting properties of common building materials such as stone, brick, timber, cast-iron, glass, steel and concrete are mentioned below. 1. STONE The stone is a bad conductor of heat. But it suffers appreciably under the effects of fire. The stone is also liable to disintegrate into small … Read more
CAUSES OF DISINTEGRATION OF CONCRETE The primary reasons that cause disintegration of concrete member are desribed below. 1. SULPHATE ATTACK Soluble sulphates are present in Ground water Soil Clay bricks Soluble sulphates react with Tricalcium Aluminate of cement I n the presence of moisture and form products which occupy much bigger volume than that of … Read more
Minimising Defects in Plastering Work Defects in plastering work can be minimised by following the below mentioned techniques. The brick and plastering work should be carried out by skilled masons in the best workmanship manner. Bond of brick work should be properly maintained. Efflorescence is removed by rubbing brushes on the damaged surface. A solution … Read more
BRICKWORK CHECK LIST FOR SITE ENGINEERS While on site, a site engineer must ensure that the brickwork is going on as per quality requirements. Some of the general requirements of quality of brickwork are mentioned below. Use this as a checklist while executing brickwork. The thickness of joint in brick masonry should not exceed 1 … Read more
Compounds of Cement About 90-95% of a Portland cement is comprised of the four main cement minerals, which are C3S, C2S, C3A, and C4AF, with the remainder consisting of calcium sulphate, alkali sulphates, unreacted (free) CaO, MgO, and other minor constituents left over from the clinkering and grinding steps. The four cement minerals play very different … Read more