Awarded as the best online publication by CIDC

Er. Kaushal Kishore

Indian Construction Industry Navratna Award 2017

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

Indian Construction Industry Navratna Award 2017

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.

Care in Concrete Mix Design

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 Ist mix design is carried out carelessly, where as the 2nd 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:

(more…)

CONCRETE QUALITY CONTROL DURING CONSTRUCTION

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.
(more…)

Concrete Strength Acceptance Criteria IRC:15-2011

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.

(more…)

Concrete Strength Acceptance Criteria IS:456-2000

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.

(more…)