www.sefindia.org

STRUCTURAL ENGINEERING FORUM OF INDIA [SEFI]

 Forum SubscriptionsSubscriptions DigestDigest Preferences   FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups  RegisterRegister FAQSecurity Tips FAQDonate
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log in to websiteLog in to websiteLog in to websiteLog in to forum 
Warning: Make sure you scan the downloaded attachment with updated antivirus tools  before opening them. They may contain viruses.
Use online scanners
here and here to upload downloaded attachment to check for safety.

Testing for Compressive Strength of Concrete Cover Blocks

 
Post new topicReply to topic Thank Post    www.sefindia.org Forum Index -> SEFI General Discussion
View previous topic :: View next topic  
Author Message
ajay84
SEFI Member
SEFI Member


Joined: 22 Aug 2010
Posts: 3

PostPosted: Wed Sep 15, 2021 3:17 pm    Post subject: Testing for Compressive Strength of Concrete Cover Blocks Reply with quote

Hello,

In absence of specific Indian standard w.r.t Concrete Cover Blocks/ Spacers, there is ample ambiguity among manufacturers, users & testing agencies.

As per IS 516, the normal rate of loading is 140 kg/sq.cm/minute for a 150X150X150 cube. I would like to know whether a concrete cover block as small as 50cmX25cmX25cm can also be tested with similar methodology to regular cubes.

Please throw some light.

Thank you.

Regards,

Ajay.
Back to top
View user's profile Send private message
Dr. N. Subramanian
General Sponsor
General Sponsor


Joined: 21 Feb 2008
Posts: 5496
Location: Gaithersburg, MD, U.S.A.

PostPosted: Wed Sep 15, 2021 9:46 pm    Post subject: Re: Testing for Compressive Strength of Concrete Cover Blocks Reply with quote

Dear Er Ajay

I do not think there is a prescribed test method for concrete covers in any code, leave alone IS 456.

The cube testing procedure will not be applicable to concrete cover blocks.

Moreover, for cover Block, more that compressive strength, durability is important. You may note that even in regular concrete getting the desired strength is not that difficult. If the design mix is M25 you will easily get more than M25 in most of the cases. But getting the durability is not assured. That is the reason why fly ash and other additives were recommended.

Warm regards
Subramanian

ajay84 wrote:
Hello,

In absence of specific Indian standard w.r.t Concrete Cover Blocks/ Spacers, there is ample ambiguity among manufacturers, users & testing agencies.

As per IS 516, the normal rate of loading is 140 kg/sq.cm/minute for a 150X150X150 cube. I would like to know whether a concrete cover block as small as 50cmX25cmX25cm can also be tested with similar methodology to regular cubes.

Please throw some light.

Thank you.

Regards,

Ajay.
Back to top
View user's profile Send private message
vikram.jeet
General Sponsor
General Sponsor


Joined: 26 Jan 2003
Posts: 3390

PostPosted: Thu Sep 16, 2021 2:52 am    Post subject: Reply with quote

CONCRETE cover blocks

For Building construction works ,their  strength is not any issue , nor it's permeability. But for water retaining structures , cover blocks cover the reinforcement at locations these are placed during execution , and needs to be durable / impermeable to protect initiation of  spot rusting of reinforcement.

Generally these are cast with richer mix than parent concrete .
Back to top
View user's profile Send private message
sspawar
...
...


Joined: 05 Jun 2009
Posts: 1196

PostPosted: Sat Oct 23, 2021 9:35 am    Post subject: Reply with quote

Dear Sefians,

In most of the valuable/Important projects - specifications for cover blocks are mentioned and elaborated well in the contracts.

Though there is no specific IS standard for testing cover block but It is desired and be mentioned in the quality plan of the projects that strength of cover blocks must be equal to the strength of concrete mix.

Quality plans describes well whether it should be site made or factory made , how would be tested. what will be the procedure for maintaining the quality.

Concrete blocks never be made of mix as of concrete which is used for structures.

Concrete blocks are generally designed and tested and approved  as  contracts describe.

Concrete blocks are generally made of mortar with finer aggregates with richer mix and additives.

Concrete blocks testing cubes are generally filled as of cement or mortar cubes.

Since site made blocks quality can not not be controlled as well as factory made and branded blocks, hence factory made made blocks are more preferred.
Sizes and varieties and making material varieties are also possible with long range from factory made products.

Third party test is commonly adapted for quality checks and control.

Standards are generally refereed as BS 7973-1 and 2 and IS 4601 and 2185 and 15658.

A manufacturer's catalog -power point is attached here for more idea regarding what is being practiced in India and abroad.

Though it is true that durability can not be ascertained as it requires a historical records and series of experiment and tests.

Regards



Warning: Make sure you scan the downloaded attachment with updated antivirus tools  before opening them. They may contain viruses.
Use online scanners
here and here to upload downloaded attachment to check for safety.
cover-blocks-concrete-astra.pdf
 Description:

Download
 Filename:  cover-blocks-concrete-astra.pdf
 Filesize:  1.7 MB
 Downloaded:  170 Time(s)

Back to top
View user's profile Send private message
Display posts from previous:   
Post new topicReply to topic Thank Post    www.sefindia.org Forum Index -> SEFI General Discussion All times are GMT
Page 1 of 1

 

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


© 2003, 2008 SEFINDIA, Indian Domain Registration
Publishing or acceptance of an advertisement is neither a guarantee nor endorsement of the advertiser's product or service. advertisement policy