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

HOW TO CALCULATE PILE LOAD CAPACITY USING STATIC CONE PENETRATION TEST?

Pile load capacity calculation using static cone penetration test data (SCPT)

Pile Load Capacity Calculation Using Static Cone Penetration (SCPT) Test Data The safe load capacity of bored cast in situ piles can be calculated using the test data obtained from static cone penetration test as described below. We know that the ultimate load capacity of pile consist of two terms, i.e. End bearing resistance Skin … Read more

HOW TO CALCULATE PILE LOAD CAPACITY IN WEATHERED ROCK OR SOFT ROCK?

Pile embeded in weathered rock

Pile Load Capacity Calculation in Weathered or Soft Rock This method of calculating pile load capacity was suggested by Cole & Stroud. Cole & Stroud used ‘N’ values or results of standard penetration tests to find allowable load capacity of the pile in weathered rocks. The formula suggested by Cole & Stroud is given below. … Read more

WHAT TO CHECK WHILE CONSTRUCTING PILE FOUNDATION UNDER WATER?

Pile foundation construction under water using tremie method

Guidelines to Follow While Constructing Pile under Water While placing concrete by tremie method, all tremie pipes should be cleaned before and after use. The diameter of tremie pipe should be preferably 200 mm for constructing piles of all diameters within 600 mm. For 25 mm down aggregate, tremie pipe should have a diameter not … Read more

HOW TO CALCULATE PILE LOAD CAPACITY IN COHESIONLESS SOIL USING SPT OR N-VALUES?

Pile load capacity calculation using standard penetration resistance

Pile Load Capacity Calculation Using Standard Penetration Resistance This method of calculating pile load capacity in cohesion less soil (i.e. in sand) was suggested by Meyerhof. Meyerhof suggested the following equation, to calculate the ultimate pile load capacity in saturated sand, using standard penetration resistance (N). In the formula given below the 1st term gives … Read more

HOW TO CALCULATE BEARING CAPACITY OF SHALLOW FOUNDATION IN SAND FROM SPT VALUES OR N-VALUES (IS-6403)

Step-by-Step Procedure for Calculation of Bearing Capacity from Standard Penetration Test Values or N-values Step-1 Perform standard penetration test on the location for which you want to calculate bearing capacity. This is done as per standard procedure given in IS-2131. Standard penetration test must be done at every 75 cm in vertical direction. Step-2 Decide … 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