There are different methods of measuring the workability of fresh concrete. Each of them measures a particular aspect of it and there is no unique test which measures workability of concrete in its totality. The three most commonly used method for testing workability of concrete are Slump test Vee-bee test Compacting factor test. The table … Read more
Aim To determine the relative density or density index of cohesionless soil Theory Relative density is also known as density index. It is defined as the ratio of difference between the void ratio of a cohesionless soil (i.e. sand) in the loosest state and any given void ratio to the difference between its void ratios … Read more
What is Blended Cement Blended cement is obtained by mixing OPC with mineral admixtures or additives like fly ash, slag or silica fumes. Blended cements are now being considered superior as compared to conventional OPC category of cements. Advantages of Blended Cement The advantages of using blended cement can be broadly be divided in two … Read more
In my previous post I discussed with you about volume batching of concrete and how it is done in field. Now let us solve an example, so that you become more confident in the field. In this example I have also tried o show you, how correction for bulking is applied and how correction of … Read more
What Is Volume Batching of Concrete? Batching of concrete means measuring different ingredients of concrete (i.e. cement, sand, coarse aggregate and water) before mixing it. When this measurement is done on the basis of volume, we call it Volume Batching. Below are mentioned some of important points to remember before adopting volume batching method in … Read more
In spite of the best precautions taken to store cement, it is found that its strength is reduced due to long storage. Efforts should, therefore, be made to store the cement for lesser time. The strength of the cement, which has been stored for a long time, should be checked before it is used on … Read more
Objective To determine the workability of freshly mixed concrete by using of Vee – Bee consistometer apparatus. Scope and Significance The workability of fresh concrete is a composite property, which includes the diverse requirements of stability, mobility, compactability, placeability and finishability. There are different methods for measuring the workability. Each of them measures only a … Read more
The following points should be remembered before proportioning a concrete mix a per IS-10262-2009. This method of concrete mix proportioning is applicable only for ordinary and standard concrete grades. The air content in concrete is considered as nil. The proportioning is carried out to achieve specified characteristic compressive strength at specified age, workability of fresh … Read more
Bleeding cannot be completely prevented as it is an inherent property of concrete. But it can be minimized if following precautions are taken. By proper proportioning of concrete mix. By mixing the concrete uniformly and completely. By using finely divided pozzolanic materials ( as it creates a longer path for the water to traverse and … Read more
What is Laitance? Laitance is caused by bleeding of concrete. In case of bleeding, only water accumulates at the top of the surface, but in case of laitance, along with water certain quantity of cement also comes to the surface, forming a thin layer of cement paste at the surface. This formation of cement paste … Read more