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

WHAT IS THE PRINCIPLE BEHIND PRESTRESSED CONCRETE?

Prestressed concrete principle and application

Prestressed Concrete Prestressed concrete is a modified form of reinforced concrete. it not only eliminates the weakness of concrete, but also makes it possible to take full advantage of compressive strength of concrete. The term “Prestressed Concrete” is applied to those reinforced concrete members in which concrete is subjected to compressive stresses, before the external … 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

HOW TO PERFORM PLATE LOAD TEST OF SOIL ON SITE?

Fig-1 (Plate Load Test Setup)

Objective To perform plate load test to obtain a load-settlement curve of a soil at a particular depth so as to estimate the ultimate bearing capacity a foundation. Apparatus Test plate of square size (300 mm or 450 mm or 600 mm or 750 mm) Hydraulic jack (50 T capacity) Hydraulic pump (50 T capacity) … Read more

WHAT ARE THE STEPS INVOLVED FOR FINISHING CONCRETE?

screeding

Finishing may be defined as the process of leveling, smoothing, compacting and otherwise treating surface of fresh concrete or recently placed concrete to produce desired appearance. Steps Involved for Finishing Concrete There are 3 different steps involved for finishing concrete, which are as given below. Screeding Floating Trowelling 1. Screeding (Step-1) This is the process … Read more

WHEN TO REMOVE CONCRETE FORMWORK?

Removal of Formwork

Removal of Forms Forms should not be removed until the concrete has sufficiently hardened in order that it can carry safely its own weight and any other live loads it is subjected to. The supporting period (period between placing of concrete in forms and removal of forms) differ according to the type of cement used … Read more

WHAT TO INSPECT DURING CONCRETING WORK?

Inspection during concreting

Careful supervision during concrete manufacture is necessary for all concreting operations such as batching, mixing, transporting, laying, compacting and curing. While inspecting concreting work following points should be remembered for effective quality control. Inspection during Concreting The concrete mix should be designed in the laboratory with the materials to be used in the field. Weight … Read more

HOW TO REPAIR CONCRETE SURFACE? (DRY PACK METHOD)

Concrete repair using dry pack method

This method is used for repairing holes having a depth nearly equal to greater than the least surface dimension, i.e. for any holes and narrow slots cut for the repair of cracks. This method is not used for shallow depressions; for filling patches where reinforcement is exposed or holes which extend through and through wall … 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