When a CJ exists in a wall does the rebar for the lap splice on the next lift need to be held 2" off the CJ?

[Tim B]

I have searched ACI 301 & 318 but cannot find an answer specific to this question. Is there someone that knows or has dealt with this in the past? Not many contractors are held to this even if this is a specified requirement since no one ever remembers being held to this standard in the past. Help please

 

[Dnyan Deshmukh]

Sorry for the late reply, its not a bar but a water stopper provided in the wall.

When we do a construction of a wall, more specifically in water bodies or retaining walls or any kind of walls which comes in contact with water, the water stopper need to be installed at each construction joint in wall when you do not want water to be entered inside.

Those water stopper can be either of rubber or GI sheet or any material as specified for use.

The stopper can either be fixed before concreting or can be inserted into concrete before it sets by 2 inches in case of 4 inch height water stop, or 3 inch in case of 6 inch high water stop.

This way the water does not get the straight direct path and it makes hard for water to find its way into inside.

 

[Dnyan Deshmukh]

The photograph is attached below for your reference to understand how water stopper looks like.

(image downloaded from google and for representation only, it does not talk about either the construction activity is done correctly or wrongly)

 

[rahuledu]

I have searched ACI 301 & 318 but cannot find an answer specific to this question. Is there someone that knows or has dealt with this in the past? Not many contractors are held to this even if this is a specified requirement since no one ever remembers being held to this standard in the past. Help please

As I understood your question, you're asking if lap bar shall be started 50 mm (2") above Horizontal construction joint. Yes, you're absolutely right about this. the reason behind to provide this gap for easy approach of concrete in area of old concrete in construction joint. If rebar will touch the old concrete, in that case, there may be a chance for improper joint of new concrete to rebar all faces as well as with old concrete. Normally it is followed for shear reinforcement i.e. stirrups and link bars but it may also be followed in Main bar.

 

[rubberpolymers]

Water Stoppers are called by different names in different regions such as - Water Stoppers, Water Bars, and Water Stop Seals. They are used to prevent seepage across concrete joints. Mostly made from Poly Vinyl Chloride polymer.

 

[Eng. Tadele]

Yes, when a construction joint exists in a wall, the rebar for the lap splice on the next lift needs to be held at least 2 inches off the construction joint. This is to ensure that the rebar can be properly placed and that the lap splice is effective. The 2-inch clearance requirement is specified in most building codes and standards, including the International Building Code (IBC) and the American Concrete Institute (ACI) Building Code Requirements for Structural Concrete (ACI 318). The clearance helps to ensure that the rebar is not placed too close to the construction joint, which could compromise the integrity of the joint and the overall strength of the wall.