Site Instruction on DBM Works

To

The Concessionaire

Subject: About completed and balance or future dense bituminous Macadam construction works-Reg.

Dear Sir,

You have completed a significant length of DBM construction work in some portion of the project highway. But you have failed to comply with the following points:

1. Till date, no RFI’s have been raised before us for checking the curb top level anywhere in the Project Highway.

2. Till date, no RFI has been raised to check the tolerance levels of the completed DBM works.

3. Further, it came to our knowledge that you are going to launch the DBM Construction works for the Package-L portion very soon. In this connection, we would like to instruct you in advance that:

   

• No DBM laying work will be acceptable to us before the completion of the review of the DBM mix design by the IE. And till date, no DBM mix design is being submitted for our review.

• After the review of the DBM mix design, the trial patches are to be constructed as per the provisions in the MORT&H for our review.

• Under no circumstances will we allow any half-width laying and compaction of DBM layers anywhere in the project highway.

So, you are being instructed to comply with the points raised in this letter.

Thanking you.

To

The Concessionaire

Subject: About On-going Dense Bituminous Macadam Construction Works-Reg.

Reference: As above

Dear Sir,

Issue:1 Non-compliance with site verbal instructions of Independent Engineer:

• In spite of our repeated objections and instructions, the qualities of the DBM construction works are getting worse.

• Your EPC is not even following the instructions of our site engineer, who remains present at the workplace.

• Some of the field engineers engaged by the EPC sometimes directly refuse to follow the instructions of our site engineers in spite of being in the faulty line, which is not acceptable to us, and if it recurs in the future, then we will be bound to instruct you to remove such persons with immediate effects.

• However, we would like to highlight time and again the serious lapses and latches for your immediate actions.

Issue:2 Non-raising of RFI’s by the contractor/Concessionaire

• We have observed that the DBM works are being taken by you without raising RFI at all.

• It is also observed that, in spite of our written instructions, you are not raising RFIs to check the tolerances of surface levels of completed DBM layers.

• Please note very seriously that DBM works taken without raising RFIs will be treated as unauthorised works only, and you will be responsible for the following complications.

• Further, until and unless the surface tolerance levels are being offered to check by us, by RFIs, we will not allow the next layers or items over these surfaces.

Issue:3 Inadequate arrangements of tools and machinery at the work site

• It has been observed that DBM works are being continued in chainages km 14.500 to 14.890 and 15.000 to 15.240, in spite of the heavy downpour, without the provisions of PVC sheets to cover the spreaded/stacked matrix against the rain.

• This not only shows your reluctance to ensure quality but also puts a question mark on the experience and planning capabilities of the concerned site people of the EPC.

• Please note that if we do not find covering sheets preserved at the working place in sufficient numbers, we will not allow any further DBM works during rainy days.

Issue:4 Improper surface preparation and priming application

• We have observed that often the mechanical broomers are not being used properly before taking up the DBM work. The sprinklers of the bitumen browser are being in semi-choked conditions, which means that the thickness of priming was improper.

• You are being instructed to use and repair the equipment’s, certainly before taking any further works.

Issue:5 Non-standard Construction joints

The qualities of the joints between consecutive patches are much below the standard; hence, you are being instructed to improve the joints to the desired level.

Issue:6 Unsatisfactory/Poor Surface finishing

During the TL of IE’s visit of the site on 22/08/2024, it was found that lots of segregations are there in the DBM layer constructed on 20/08/2014, for the chainage 14.500 to 14.890.

On detailed scrutiny, it was decided by the IE that the DBM laid within the chainage 14.875 to 14.890 is to be removed, relayed, and recombined with immediate effect. You are being instructed to comply with the same.

Issue:7 Site-level quality control tests

It has been observed that in the cases of completed DBM layers, neither the cores are being taken as per the frequencies nor in the presence of IE’s representatives. Please rectify your modus operandi.

Issue:8 About the riding quality of the DBM

During the visit of the Project Highway on 08/08/2024, the Highway authority expressed his deep concern about the riding quality of the DBM in section 4.

So, you are being instructed to improve the surface regularities to the desired level, with immediate effect.

Issue:9 Other & miscellaneous work

During the visit of the Project Highway by the T.L. of IE, it has been found that the kerb heights for the LHS and RHS of the same patch for chainages 18.000 to 18.500 are not the same.

You are being instructed to rectify the same and ensure that it does not recur in the future. All these are for immediate compliance only.

Thanking you,

Case-1

To

The Concessionaire

Subject: DBM works-Section 3- Reg

Dear Sir,

It has been observed that, you have just started the DBM work in package III of the Project Highway, with following serious discrepancies:-

1. Neither you have submitted any DBM mix design for IE’s review nor you have submitted any DBM construction methodology so far.
2. As per the table B3 of schedule B of Concession Agreement, the minimum DBM layer thickness must be 105 mm but you are constructing the DBM by Grade 1 bitumen mix with 100 mm thickness.
3. Now as per table 500-10 of MoRT&H, the range of Grade 1 bitumen thickness must be in between 80 mm and 100mm. so you are not in a position to use gradel mix for a bitumen layer of thickness 105 mm. Hence you have to use grade Il mix only which you are non complying.

So, under the above circumstances, we would like to intimate you that, we are not in a position to accept unauthorized modifications of Concession Agreement Provisions, hence, you are being instructed to stop the unauthorized DBM construction works with immediate effect, else you will be responsible for the adverse consequences.

Thanking you.

Case-2

To

The Concessionaire

Subject: Deficiencies in DBM Construction works- Reg.

Dear Sir,

During our team’s recent site visits, we have found following deficiencies:-

1. The DBM over lay was completed in the following chainages without submitting the existing bituminous road top levels to finalize the ultimate overlay thickness.

2. The Overlay works were completed from Ch 15+060 to Ch16+100, without construction of Krebs.

3. You have laid the kerb on existing bituminous road from Ch15+010 to Ch 15+920 LHS, which are not being executed as per drawings submitted by you.

4. Kerb lying was completed from Ch 14+020 to Ch 14+250 BHS, but not are in alignment and top levels are not matching.

Hence, you are being instructed to improve your workmanship and rectify the deficiencies. With immediate effect.

 Thanking you,

The concessionaire

Subject: – Undulations and settlement observed on DBM surface

Dear Sir,

Please refer to the site visit of the under signed on 1st September 2024. The undulations and settlement were observed at following locations of the Newly Constructed Road at the following Chainages.

1) Ch.05+000 to Ch.05+900

2) Ch.06+550 to Ch.10+350

3) Ch.10+560 to Ch.11+400

We have previously brought to your notice that Wet Mix Macadam is laid directly on the existing/erst-while bituminous surface at these portions. The existing/former bituminous surface in the median areas is not removed which created drainage problem in the median resulting in undulation and settlement on pavement surface.

Thus, the existing road to be reconstructed at cited locations based on our pavement Engineer site visit/site observations. Further, (After attending the notified defect i.e. rectification by reconstruction)to submit reconstructed DBM top surface levels/ surface regularity results of these locations for our review.

Thanking you