7 STRUCTURAL EFFECTS OF SHRINKAGE ON CONCRETE STRUCTURES

shrinkage cracks in concrete

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

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

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 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

WHAT TO CONSIDER WHILE USING PPC, BFSC OR MINERAL ADMIXTURE IN CONCRETE?

point to consider while using mineral admixture in concrete

Points to Consider Mixing of mineral admixtures with OPC at site should not normally be permitted. However for projects requiring use of blended cement from durability and strength considerations, which is not available from the cement manufacturer blending may be permitted through a specific facility created at site with complete automated process control to achieve … Read more

WHAT ARE THE MINERAL ADMIXTURES USED IN CONCRETE?

mineral admixuture-Metakoalin

The following 4 mineral admixtures can be used for making concrete. Rice husk ash Metakaolin Silica fume Fly as 1. Rice Husk Ash It is obtained by burning the rice husk in a controlled manner without causing environmental pollution. This is generated in huge quantity in the rice shelters and each tone of paddy produce … Read more