Suryakanta The following light weight aggregates are generally used to produce lightweight concrete: Breeze or Clinker These aggregates are obtained from coal and are very light. Some types of coal produce clinker which expands on coming in contact with water and is injurious to concrete causing it to crack. The more the combustible matter remaining in … Read more
Fibre Reinforced Concrete Fibre reinforced concrete is a composite material consisting of cement paste, mortar or concrete with closely spaced and uniformly dispersed fibres of polypropylene, nylon, asbestos, coir, glass and carbon (circular or flat). Properties Fibres introduced in concrete impart the following properties: Increased static and dynamic tensile strength Improved impact strength Limited crack … Read more
Introduction Specific gravity is defined as the ratio of the mass of a given volume of the bituminous material to the mass of an equal volume of water, the temperature of both being specified as 270C. Apparatus Specific gravity bottle of 50 ml capacity, ordinary capillary type with 6 mm diameter neck or wide mouthed … Read more
Polymer Concrete Polymer concrete is conventional concrete made with ordinary Portland cement wet cured, and impregnated with a liquid/gaseous monomer (methyl methacrylate) and polymerized by gamma radiation or chemically initiated means i.e. by using thermal catalytic method (adding 3% by weight benzoyl peroxide) to the monomer as a catalyst. The impregnation is aided by drying … Read more
Vacuum Concrete The concrete from which water is extracted by a vacuum process before the hardening takes place is known as vacuum concrete. The type of concrete having relatively high slump in order to achieve consolidation is usually useful in case of thin slabs and walls. This is achieved by withdrawing considerable amount of water … Read more
Lightweight Concrete It may be defined as the concrete of substantially lower unit weight than that made from gravel or crushed stone. Ordinary concrete is quite heavy and its density is 2300 kg/m3. It is not suitable for use in floor filling as filler in general. If used, it adds considerably to the dead weight … Read more
Aggregate impact value test gives an indication of aggregate’s toughness property (i.e. property of a material to resist impact) Aggregate impact values are used to classify the stone aggregates with respect to toughness property as given below. Aggregate impact value (%) Toughness Properties <10 Exceptionally tough / Strong 10 – 20 Very tough / Strong … Read more
No Fines Concrete No fines concrete may be defined as concrete mixtures containing little or no fine aggregate. The fine aggregate is not added in this concrete so that there are voids left in the coarse aggregate. The coarse aggregate may be any of the usual type or the light weight aggregate. The coarse aggregate … Read more
Aerated Concrete Aerated concrete may be defined as concrete made very light and cellular by the addition of prepared foam or by generation of gas within the unhardened mixture. It is also termed as cellular concrete and foamed concrete. By Generation of Gas The addition of powered aluminium or zinc to the cement causes evolution … Read more
What is Ready Mix Concrete? The concrete which is mixed in the agitator trucks or at the central batching plant and is delivered at site is known as ready mix concrete. It is used where there is shortage of space for the procurement of the material, where the site is very congested. What Are The … Read more