Objective To determine the Flexural Strength of Concrete, which comes into play when a road slab with inadequate sub-grade support is subjected to wheel loads and / or there are volume changes due to temperature / shrinking. Reference Standards IS: 516-1959 – Methods of tests for strength of concrete Equipment & Apparatus Beam mould of size … Read more
Concrete structures which are subjected to freezing and thawing are likely to deteriorate earlier. Structures which are mostly affected under similar climatic conditions due to freezing and thawing are the exposed surfaces of the top 60 cm of walls, piers, parapets, cornices etc. the durability of such structures can be improved by adopting certain weather … Read more
Theory The bond strength is the measure of the effectiveness of the grip between concrete and steel and has no standard quantitative definition. In pull out tests on plain bars, the maximum load generally represents the bond strength that can be developed between concrete and steel. With plain bars the maximum load is not very … Read more
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
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
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
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
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