Question

Question 2 a. Under what circumstances at tender preparation stage, the provisional quantities and provisional sum shall be allowed in bills of quantities, instead of the firm quantities? Please describe respectively. [10 marks] 6. Calculate the steel to concrete ratio (kg/m) for the beam based on the following information Elements Concrete voluine (ln) Steel to concrete ratio (kg/m3) Column 6,000 250 Slab 12,000 150 Beam 10,000 Structural wall 6,000 200 Non-structural wall 1,000 80 Staircase 1,000 100 Total provisional quantities of reinforcement = 6,180,000 kg (5 marks] c. Calculate the cost adjustment to the original contract sum for the re-measurement of the reinforcement based on the given information in Appendix A. [Reminder: You need to calculate the as-built reinforcement quantities in different sizes based on the following information:] Elements Links, stimups. binders and the General reinforcement like Column 12mm dia.: 430,000 kg. Slab 10 mm dia.: 480,000kg Beam 12 mm dia.: 500,000kg 32mm dia.: 500,000kg 40mm dia.: 600,000kg. 25mm dia.: 480,000kg 32mm dia.: 620,000kg. 25mm dia.: 350,000kg 32mm dia.: 520,000kg 40mm dia.: 360,000kg 25mm dia.: 250,000kg 32mm dia.: 375,000kg 40mm dia.: 260,000kg 20mm dia. : 57,000kg Structural wall 12mm dia.: 350,000kg 10mm dia.: 26,000kg Non-structural wall Staircase 10mm dia. :32,000kg 25mm dia.: 69,000kg [10 marks)

Answer 1

(6) Given Total polovisional Quantities of reintocement = 6180oookg Total concrete Volume = - [6000+12000+10000+6000 +1000+1000 = 36000m3 steel to Conolete ratio 11 16180 000 =171.66 kg/m3 36000 calculation of rate: (C) Elements Link, stirrups, binders (Rate) Column 430000X12 5160000 General reinforcement (Rate) 500000X15-75X105 600 000X15 790 X105 480000x152728105 480000X12 slab - 5760000 Beam 500000X12 = 6000000 620000X15293X105 350 000X15? 52.5X105 520000X15= 78 X105 360 000X1554 X105 250 000X150375X105 375 000X15:56.25 X105 260000X15= 39x105 350000X12 structural Wall 4200000 57 000X15-8.55 X10S Non 26000 X2 structura = 312000 wall staircase 32000X12 = 384000 Total 21816000 69000X1510035X 105 66605000

Total date =(21816000+66605000) 88421000 Jotal rate from appendix(A) for general reinforcement ana stirrups, links, bindess 15750000+ 15750000 +15750000 +15750000+ 10 800 000 f10800000 그 84600000 ". The cost adjustment to the original contract sum for re measurement of the reinforcement based on given information in Appendix (A) 88421000-84600000] [s. 3821000 Answor
(a) Provisional sums

It is provided in different ways in different forms of contract and some forms of contract can be a little vague about how provisional sums should be handled, in particular regarding adjustments to the programme.

There may be issue if the employer decides to omit work related to a provisional sum from the contract, as the contractor may claim for loss of profit, unless the contract allows the work to be omitted.

It is very important therefore that parties to the contract familiarise themselves with the exact wording and meaning of the relevant clauses that are being used.

In addition, agreeing the actual costs associated with provisional sums of time that might be claimed can result in tension between the contractor and client.

Due to these reasons, provisional sums should only be used as a last resort, they should not be an easy fall-back position for consultants when designs are incomplete or information is difficult to obtain.

Provisional Quantities

The items or components of work for which exact requirements and quantities are not known at the time of tendering. Payment to the contractor is done on the basis of the actual work carried out at rates agreed in the contract.

The variance between provisional quantity and firm quantity measured is less than 20 per cent, the rate tendered by the contractor shall not be subject to review.

Where the variance is significant (i.e. 20 per cent or more), the rate can be reviewed to ensure that the rate is fair and reasonable to both the employer and contractor.