Importance and Need of Non-Destructive Testing It is often necessary to test concrete structures after the concrete has hardened to determine whether the structure is suitable for its designed use. Ideally such testing should be done without damaging the concrete. The tests available for testing concrete range from the completely non-destructive, where there is no … Read more
Pile Classification Based On Construction Method On the basis of method of installation pile foundations can be divided into the following 6 types. Precast Driven Piles Driven Cast-in-situ Piles Bored Cast-in-situ Piles Bored Precast Piles Driven Steel Piles Driven Timber Piles 1. Precast Driven Piles These are usually of RCC or pre-stressed concrete and generally … Read more
Harmful Effects of Dampness Dampness is the presence of hygroscopic or gravitational moisture. Dampness gives rise to unhygienic conditions apart from reduction in strength of structural components of the building. Dampness causes the following harmful effects. Dampness is responsible for breeding of mosquitoes and creates unhealthy living conditions. Due to dampness, moisture travel through walls … Read more
Precast Concrete Piles – Advantages & Disadvantages Precast concrete piles are cast, cured and stored in a yard before they are installed in the field mostly by driving. Advantages of Precast Concrete Piles Reinforcement used in the pile is not liable to change its place or get disturbed The defects in pile can be easily … Read more
Soil Test to Find Organic Matter Content in Soil Purpose Deleterious contents of soil such as organic matter affect its characteristics and behavior adversely and must therefore be within 2%. Procedure Take an air dried sample of soil and determine its moisture content. Using another sample, produce about 100 g of soil passing the 10 … Read more
Determination of Soluble Sulphate Content Purpose Sodium sulphate is present in some soils. The salt is easily hydrated and dehydrated under the influence of climatic changes. There are enormous volume changes during this process of hydration and dehydration, which influence the engineering properties of soils. Procedure Take the soil sample in a state in which … Read more
Drum Type Concrete Mixer Classification This is also called as free fall mixer or gratify mixer. In this type of mixer, concrete is mixed by lifting the ingredients with the help of fixed blades inside a rotating drum and then dropping the material by overcoming the friction between the mixture and the blades. The drum … Read more
Parameters to Consider Before Selecting Concrete Batching and Mixing Plant 1. Capacity of Plant In order to meet the requirement of project specific parameters as mentioned above, a concrete plant of right capacity should be installed. It should take into account various ingredients proposed for use in the mix like, fly ash, admixtures like plasticizer, … Read more
Test to Check Total Calcium Oxide in Lime Purpose The lime should have a purity of at least 70% by weight of CaO when tested as follows: Procedure Take one gram of powdered lime, accurately weighed, in a platinum crucible. Place it in an oven maintained at 105 + 20C until, on cooling and weighing, … Read more
Concrete Mix Design – Basic Considerations The proportioning of concrete mixes consists of determination of quantities of different concrete-making materials necessary to produce concrete having the desired workability and 28-days compressive strength of concrete for a particular grade of concrete and durability requirements. Emphasis is laid on making the most economical use of available materials … Read more