# Question: Why is staggered lapping of reinforcement?

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Staggering lapped joints increases the complexity of detailing and steel fixing, and may require additional resources and slow construction on site. Major design codes encourage staggering lapped joints in tension by imposing a penalty on lap length depending on the proportion of bars lapped at the same section.

## What is staggered lap?

b, Lap splices shall be considered as staggered if the centre-to-centre distance of the splices is not less than 1.3timesthe lap length calculated. You can read more about rebar lap rules in one of our previous blogs.

## Why is lapping done in reinforcement?

Lap length is one of the important term in the reinforcement. During the placement of steel in Reinforced concrete structure, if the required length of single bar may fall short. To get the desired design length, lapping of two bars side by side is done. An alternative to this is to provide mechanical couplers.

## What is joggling reinforcement?

When we provide lapping in the reinforcement bars, we bend either of the two bars to align them with each other. These bent-up bars are called joggled bars in the civil field. Sometimes, the bars provided in the structural members offset their original position due to technical and human errors.

## What is the minimum lap length?

What is the minimum lap length? For direct tension, the straight length of the lapping bar shall not be less than 15d or 20 cm. While in the case of compression lapping should not be less than 24d.

## What is unit of steel?

Unit mass of steel is the ratio of weight of Steel to its per unit volume. Usually it is expressed in kilograms per cubic metre or Pounds per cubic feet. Unit mass of steel is 7850 kg/m3 (kilograms per cubic metre) or 490 lbs/ft3 (pounds per cubic feet).

## How is Laplength calculated?

2. Lap length in TensionClass A Splice: Lap Length ls = 1.0 ld.Class B Splice: Lap Length ls = 1.3ld.ls = 0.0005fy (d) ; [ For fy less than or equal to 60,000psi]ls = (0.0009fy – 24)d; [ For fy > 60,000 psi]19 Oct 2019

## What is Lap length of steel?

Normally, steel bars have a 6m length. If length of a bar is not enough to keep the reinforcement, we have to lap two steel bars. Normally, lapping position is at where near the minimum shear force is acting. Normally lap length is 50D meaning 50 times the bar diameter if both bars are of same diameter.