WHAT ARE THE ADVANTAGES & DISADVANTAGES OF CONCRETE?

Effect of hot and cold weather on concrete

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

WHAT FACTORS INFLUENCE CORROSION OF REINFORCEMENT IN CONCRETE STRUCTURE?

factors influencing corrosion of reinforcement in concrete structure

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

HOW TO DETERMINE DRYING SHRINKAGE OF HARDENED CONCRETE?

Length Comparator for measuring initial drying shrinkage of concrete specimen

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

WHAT ARE THE PROPERTIES OF FRESH CONCRETE?

Properties of Fresh Concrete

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

WHAT IS RETEMPERING OF CONCRETE?

Retempering of concrete

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

WHAT IS NON-DESTRUCTIVE TESTING OF CONCRETE & VARIOUS NDT TEST METHODS?

NDT test on concrete

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

WHAT CAUSES CRACKS IN CONCRETE AND HOW TO PREVENT IT?

causes of cracks in concrete and its remedies

Causes of Cracks in Concrete and its Remedies Cracks in concrete are caused due to following factors. One of the main causes of cracks in concrete is the cooling and contraction due to setting of concrete. Volume change and stresses due to shrinkage are independent of any external load or stress applied. Cracks may develop … Read more

WHAT IS CARBONATION OF CONCRETE?

What is carbonation of concrete

Carbonation of Concrete Carbonation of concrete is one of the reasons for corrosion of reinforcement. It is a process by which carbon dioxide from air penetrates into the concrete and reacts with calcium hydroxide to form calcium carbonates. The percentage of CO2 present is air vary from place to place. In case of rural areas … Read more

HOW TO DECIDE MAXIMUM SIZE OF COARSE AGGREGATE TO BE USED IN CONCRETE?

how to decide maximum size of aggregate to be

For the same strength or workability, concrete with large size aggregate will require lesser quantity of cement than concrete with a smaller size aggregate. In a mass concrete work the use of larger size aggregate will be useful due to the lesser consumption of cement. This will also reduce the heat of hydration and the … Read more