Effect of Shrinkage on Concrete Structure When concrete structures are not permanently water-saturated, it starts to lose moisture and starts to shrink from the time when the process of curing ceases. The structural effects of shrinkage area as follow. 1. Joints Shrinkage of concrete between movement joints causes joints to open or makes it wider. … Read more
Qualities of Good Timber Good timber should have the following qualities 1. Hardness A good quality timber should be hard enough to resist deterioration. 2. Strength It should have sufficient strength to resist heavy structural loads. 3. Toughness It should have enough toughness to resist shocks due to vibrations. It should not break in bending … Read more
Engineering & Physical Properties of Stones The following are the engineering and physical properties of the stones that should be looked into before selecting them for engineering works: 1. Structure The structure of the stone may be stratified (layered) or unstratified. Structured stones should be easily dressed and suitable for super structure. Unstratified stones are … Read more
Slump Cone Test of Fresh Concrete Object This test is performed to measure consistency or workability of fresh concrete, where the nominal maximum size of aggregate does not exceed 38 mm using slump test apparatus. Reference Standards IS : 1199 – 1959 – Method of sampling and analysis of concrete. Equipment & Apparatus Slump cone (Height … Read more
Advantages of Concrete The following are the advantages of concrete Concrete ingredients are easily available. Concrete can be easily handles and moulded to any desired shape. Concrete can be easily transported from the place of mixing to place of casting before initial set takes place. Concrete can be pumped or sprayed to fill into cracks … Read more
Basic Components of Paints Paint is a very complex material consisting of many components. Modern paints can have ten to twenty components, each responsible to give a specific quality to the paint. However, basically all paints consist of the following five components. 1. Base Pigment White lead, red lead, aluminium powder, etc were the pigments … Read more
Timber Classification The terms timber and wood are often used synonymously, but they have distinct meanings in the building industry. Wood is the hard, fibrous material that makes up the tree under the bark, whereas timber may be defined as a wood which retains its natural physical structure and chemical composition and is suitable for … Read more
Determination of Residue of Bitumen Emulsion Purpose This test is done for the determination of residue of bituminous emulsion by sieving through 600-micron is sieve. Apparatus 600 Micron IS Sieve — A circular sieve approximately 100 mm in diameter and 40 mm height. Metal or Glass Dish — A small metal or glass dish about … Read more
Lime Reactivity Test Purpose This method of test covers the procedure for determining the reactivity of the pozzolanic material (such as fly ash) with hydrated lime, as represented by compressive strength of standard mortar test cubes prepared and tested under specific conditions. Size and Number of Test Specimens The tests specimen shall be 50 mm … Read more
Bitumen Content Test of a Bituminous Mix Purpose The test determines the bitumen content in the bituminous mix by cold solvent extraction. Apparatus & Solvent Centrifuge apparatus Trichloroethylene Procedure Take a representative sample of about 500 g, weigh it exactly and place it in the bowl of the extraction apparatus (W1). Cover the sample with … Read more