Although the advantages of mechanical splices are well recognized, a major concern has been their high cost for applications where the codes permit the use of lap splices. But is the perception that mechanical splices cost more than lap splices a reality? By using couplers, contractors can be more cost efficient, able to achieve from 20-50% of cost savings compared to lap splicing. Apart from that, there are many other savings which can be anticipated such as;

Reduction no. of joints

6 meters length will be most ideal for joining and this would result in reduction of no. of laps by,

Assuming height of building: 100 metres

Typical floor height: 3.2 metres

No. of laps: 100 / 3.2 = 31 laps

No. of coupler joints: 100 / 6 = 16 joints

Therefore reduction in no. of laps: [(31-16)/31] x 100% = 48%

Minimal wastages of HTDBs

Assuming floor height of 3.2m and lap length of 1.275m

Length of steel bar per floor is : 3.2m + 1.275m = 4.475m

For a 12metres steel bar, two nos of 4.475metres length bar could be prepared.

Balance: 12metres –4.475metres –4.475metres = 3.05metres

By adopting a 6m bar for coupler joint. No wastage is anticipated. Therefore wastage occurred due to lapping is (3.05m/12m)*100% = 25.42%

From above the calculation of mechanical splice, we can see that it is economic to use mechanical splices in the construction, that is reason why we should use rebar splice now.