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.

Minimum bar curtailment length in two way Post-Tensioned Flat System as per ACI 318 or IS Code!

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


Joined: 21 Jun 2011
Posts: 4
Location: Bangalore, India

PostPosted: Mon Jun 14, 2021 3:53 pm    Post subject: Minimum bar curtailment length in two way Post-Tensioned Flat System as per ACI 318 or IS Code! Reply with quote

Hi Fellow Engineers, I have a query on the above mentioned topic.

ACI 318-19, Fig. 8.7.4.1.3 shows the minimum extension lengths for two way (non-PT) flat slab system. (i.e., 0.33ln & 0.20 ln). Similarly IS code requires 0.33ln & 0.25ln)

Would the same extension lengths apply for two-way PT Flat slab system? If no, can anyone help with the ACI clause suggesting about it. Design is being carried out in ADAPT Builder 2019!

Thanks in advance!!
Back to top
View user's profile Send private message Visit poster's website
vikram.jeet
General Sponsor
General Sponsor


Joined: 26 Jan 2003
Posts: 2952

PostPosted: Tue Jun 15, 2021 3:36 am    Post subject: Reply with quote

ANALYSIS IS UNIVERSAL
DESIGN  IS NATIONAL
DETAILING IS PERSONAL

MODELLING NEEDS TO BE IDEAL

Since design has to be carried as per The specific Country Code where such structure is to be constructed,  for Indian sites, you need to follow IS Code recommendations.

Earlier IS 456 version for general slabs recommended 0.3L ,0.20L but 1978 code revised to 0.3 and 0.25.
Back to top
View user's profile Send private message
vikram.jeet
General Sponsor
General Sponsor


Joined: 26 Jan 2003
Posts: 2952

PostPosted: Tue Jun 15, 2021 6:45 am    Post subject: Reply with quote

For PT slabs, please also see guidelines in 19.6 of IS 1343 , regarding transmission length.
Back to top
View user's profile Send private message
pvgraju
SEFI Regulars
SEFI Regulars


Joined: 07 Jun 2020
Posts: 28

PostPosted: Thu Jun 17, 2021 3:38 am    Post subject: Minimum bar curtailment length in two way Post-Tensioned Flat System as per ACI 318 or IS Code! Reply with quote

Dear Sir,

Post tensioning can be done for bottom bars since bottom bending will be dominant in slabs. PT will make slab econimical. Generally top bending will be less ,it can be designed like a RC element with 0.3L extension.

These extension lengths are minimum lengths specified in the code. At 0.3l top bending will be zero. So top reinforcement is not needed after that. In case of PT also bending moment values will be same. So extension will be same.

Regards,

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


Joined: 26 Jan 2003
Posts: 2952

PostPosted: Sun Jun 20, 2021 4:16 am    Post subject: Reply with quote

For Cantilever Slabs , the hogging moment at top may require higher top bars reinforcement embedment length at back slab .  Generally it needs to be around 2*L , where L is cantilever span of slab projection. This length takes care of situation ( Full LL on cantilever & No LL on back slab)
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