Er. Kaushal Kishore

By
Kaushal Kishore
Materials Engineer, Roorkee

Self-compacting concrete (SCC) is a special type of concrete which can be placed and consolidated under it’s own weight without any vibration effort due to it’s excellent deformability, and which at the same time is cohesive enough to be handled without segregation or bleeding.

WORKABILITY:
The workability of self-compacting concrete is measured by the usual slump cone having a base diameter of 200mm, top dia 100mm, and height 300mm. The slump cone is to be placed as usual upon a base plate square in shape is having at least a 700m side. Concentric circles are marked around the center point where cone is to place. A firm circle is drawn at 500mm diameter. Read More

Fare we’ll from my IIT, Roorkee Laboratory.
Whole civil engineering department was talking
A young boy is coming to hold my hand
I still remember it was raining
When Dr. Jai Krishna give my hand in your hands
My whole body thrilled while my hand was in your hands
I feel myself lucky and glad
A very handsome boy is going to be mine
God only knows for how much time
I was poor and totally nacked
You decorate and made me richest
I could not sleep whole night
As tomorrow you are going to leave me
I hear the sound of clappings
For your Praise from the head of IIT
but my heart was weeping
As soon I will not see you again
The. You come look at me
Look at the mechines you had installed
At a last look at me
You left me for ever
Believe me my love
You will always be in my heart
I will always be only yours
I will pray for your peaceful long and healthy life
God bless you.
– Kaushal Kishore

We at engineeringcivil.com are pleased to announce that our website supporter and regular contributor, Sir. Kaushal Kishore have been awarded “Indian Construction Industry Navratna Award 2017” for his Academic Contribution to the Indian Construction Industry by Builders Association of India

We congratulate Sir. Kaushal Kishore and hope his work in civil engineering field gets more and more recognition and we here at engineeringcivil.com continue to get his support and knowledge which will be of tremendous use to the upcoming engineers.

By
KAUSHAL KISHORE
Materials Engineer, Roorkee

While carrying out Concrete Mix Design, there are chances that we do not consider some technical points resulting the production of poor quality concrete. This is best illustrated by the following two examples. The I^st mix design is carried out carelessly, where as the 2^nd mix design is worked out taking into consideration all technical points. In both mix design examples the materials and requirements are same as given below:

1. Cement, PPC, 7-days strength 36.5 N/mm² and 28-days strength 46.8 N/mm². Specific gravity 3.0
2. Aggregates grading are as given below:

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By
1) KAUSHAL KISHORE
Materials Engineer
Roorkee
Kaushal Kishore is retired from IIT, Roorkee and now a Consulting Materials Engineer. He has over 50 years of experience in all types of Concrete Mix Design.

2) RAKESH SHARMA
Vice President Project
Supertech Limited
Rakesh Sharma is Vice President Project of M/s Supertech Limited. He has 28 years of experience in Construction.

I.T. Park, Doon Square Mall at Dehradun, Uttarakhand is being constructed by M/s Supertech Ltd. For this site M-30 grade of concrete suitable for pumped concrete is required. Aggregates for construction was stored at site. Its analysis report is given in Table 2.

For laboratory trial 5 brands of PPC cement bags were taken from local market. They were identified as cement brand, 1, 2, 3, 4 and 5. Two reputed brands of normal superplasticizers based on sulphonated naphthalene formaldehyde (SNF) were taken for trials. They were identified as SP (A) and SP (B) to find their compatibility with the given 5 brands of PPC cement identified as cement brand 1, 2, 3, 4 and 5.

COMPATIBILITY
The behavior of concrete in the presence of superplasticizers is related to the amount and type of sulfate added to the clinker. The rheological and setting Behavior are changed depending on whether the sulfate is added as anhydrite, hemihydrates, or gypsum. The difference are explained by the different rates of dissolution of these sulfates.
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By
KAUSHAL KISHORE
Materials Engineer, Roorkee

For concrete roads, flexural strength of concrete is the design criteria. For all major projects, flexural strength of the mix shall be determine by third point loading of flexural beams size 150 mm x 150 mm x 700 mm as per IS: 516. Determination of flexural strength by correlating with cube strength (compressive strength) shall not be allowed for major projects, as the correlation is not well established.

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By
KAUSHAL KISHORE
Materials Engineer, Roorkee

Strength of concrete is commonly considered its most valuable property, although in many practical cases, other characteristics, such as durability and permeability, may in fact be more important. However, the strength of concrete is almost invariably a vital element of structural design and is specified for compliance purposes.

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By
KAUSHAL KISHORE
Materials Engineer, Roorkee

A simple method of concrete mix design for pumpable concrete based on an estimated weight of the concrete per unit volume is described in the paper. The tables and figures presented are worked out by the author from a wide range of Indian materials. The method is suitable for normal weight concrete with admixture.

INTRODUCTION
Pumped concrete may be defined as concrete that is conveyed by pressure through either rigid pipe or flexible hose and discharged directly into the desired area. Pumping may be used for most all concrete construction, but is especially useful where space or access for construction equipment is limited.
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By
KAUSHAL KISHORE
Materials Engineer, Roorkee

Most of our construction sites do not have field-testing laboratory. In this paper simple test methods of construction materials are described which could be performed without any machine or special equipments.

1. TEST FOR ORGANIC IMPURITIES IN FINE AGGREGATE
The aggregate must be checked for organic impurities such as decayed vegetations, humus, and coal dust, etc. Colour test is a reliable indicator of the presence of harmful organic matter in aggregates except in areas where there are deposits of lignite.

Procedure:
a) Fill a 350 ml clear glass medicine bottle upto 75 ml mark with a 3% solution of caustic soda or sodium hydroxide.
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By
KAUSHAL KISHORE
Materials Engineer, Roorkee

The time lag (usually 3 to 28 days) between concrete placement and the evaluation of cube strength is a primary deficiency of the current quality control method used in concrete construction. The development of accelerated curing techniques have reduced the lag time to 24 to 48 hours. But even the 24 hours time is sufficient to allow the concrete to set and harden in the form prior to the testing of the accelerated cubes. This paper describes the method for determination of water-cement ratio of the mix discharged from the mixer and conjunction with air-content tests can predict 28-days strength of concrete in 15 minutes, so that any mix found sub-standard should not be allowed for placement.

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