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
Factors influencing Corrosion of Reinforcement In reinforced cement concrete construction the corrosion of reinforcement takes place due to the presence of chlorides and sulphates beyond a critical limit and when sufficient alkalies is not obtained within the concrete to maintain steel in a positive condition. The following factors are responsible for corrosion of steel reinforcement … Read more
Aim This test method describes the procedure for determining the drying shrinkage or change in length of concrete specimen due to changes in moisture content. Apparatus A length measuring apparatus incorporating a dial gauge capable of measuring the length accurately to 0.005 mm. (see fig shown below) Drying oven capable of maintaining a temperature of … Read more
Properties of Fresh Concrete Concrete remains in its fresh state from the time it is mixed until it sets. During this time the concrete is handled, transported, placed and compacted. Properties of concrete in its fresh state are very important because the influence the quality of the hardened concrete. The fresh concrete has the following … Read more
Retempering of Concrete When water is added to a stiffened concrete or partially set fresh concrete in order to bring it back to the desired consistency or workability, then it is called “retempering of concrete’. Importance of Retempering of Concrete The one and only reason for retempering of concrete is to regain the lost workability … Read more
Non-Destructive Testing of Concrete (NDT on Concrete) Non destructive test is a method of testing existing concrete structures to assess the strength and durability of concrete structure. In the non destructive method of testing, without loading the specimen to failure (i.e. without destructing the concrete) we can measure strength of concrete. Now days this method … Read more
Self Compacting Concrete (SCC) The term SCC in concrete technology means self compacting concrete. In this type of concrete you do not need to use any kind of vibrator to compact it and still you can achieve a concrete which is better and more reliable and uniform in quality and having high degree of performance. … Read more