Mix Design Approval Letter

To

The Authority/IE/AE/PMC,

Subject: Submission of M20-grade concrete mix design for kerb height raising (Reg).

Dear sir,

In terms of the subject, we are submitting the M20 grade concrete mix design for median kerb height raising. The independent consultant granted approval for this design during the initial construction phase. In this context, you may conduct cross-verification for the above-submitted mix design.

This is for your kind information and approval, please.

[Yours,]

[Insert the name of the authorized person].

To

The Authority/IE/AE/PMC,

Subject: Submit 7-day M20-grade concrete cube test results for mix design approval (Reg)

Dear sir,

In continuation of the above-cited, we are herewith submitting a 7-day cube strength of M20 grade concrete. We are also submitting course and fine aggregate grades (20 mm, 12 mm, sand). which were verified by your representative.

This is for your kind information and approval, please.

[Yours,]

[Insert the name of the authorized person].

The Concessionaire,

Subject: Review, observations, and comments on cube test results (Reg).

Dear Sir,

We refer to the letter cited above, in which you submitted the 7-day compressive strength of M20-grade concrete. Along with the grades of coarse and fine aggregate proposed to be used for raising the median kerb height, Our Quality Control Material Expert (QME) has reviewed your submission and provided the following comments:

Comments from QME:

1. According to the submission, the concessionaire carried out the trail mix to confirm the previously approved design mix.
2. We find that the 7-day cube strength is lower than the submitted design mix during the construction phase.
3. This mismatch may be due to
4. Modifications to the aggregate source
5. The properties of the aggregate,
6. The type of cement used, etc.
7. We request that you execute the design mix in accordance with IS 10262 and MORT&H specifications.

Note: Along with the cube strength, you must submit a test report that analyzes all the ingredients that make up the concrete mix design, including the aggregate (coarse and fine), water, and cement.

Upon receipt and verification, we will grant mix design approval.

Therefore, we request that you adhere to the QME’s comments and resubmit the design mix of M20-grade concrete for our additional review and feedback.

[Yours,]

[Insert the name of the authorized person].

Suggested to read about the permission for check posts on highway

And repair procedure of highway elements

To

The Concessionaire,

Subject: Observations on submitted Third Party Test Reports of Mix Design M20—Reg.

Dear Sir,

It focuses on the subject matter. You have provided IE with third-party test reports on the design of an M-20-grade concrete mix, which IE has provisionally reviewed. Further, we would like to instruct you to please conduct a design trail mix (M20) in an in-house laboratory for quality conformation.

According to Part III, Article 13, Clause 13 of the CA (see below), the concessionaire must conduct the tests in addition to an independent lab test for its own quality assurance, which is a good industrial practice.

The Mix Design Approval Letter outlines the contractual provisions for testing.

The construction works shall conform to the specifications and standards, and the independent engineer shall require the concessionaire to carry out or cause to be carried out tests at such time and frequency and in such manner as may be specified by the independent engineer from time to time, in accordance with good industry practice for quality assurance.

The size of the sample for these tests should typically be 10% (ten percent) of the quantity and/or number of tests prescribed by the IRC and/or Highway Authority for the construction works that the Authority, through its contractors, undertakes.

With due diligence, the concessionaire must conduct or arrange for the conduct of all tests in accordance with the independent engineer’s instructions, then provide the independent engineer with the results.

In the event that the results of any tests conducted under this clause establish any defects or deficiencies in the construction works, the concessionaire shall carry out remedial measures and furnish a report to the independent engineer on this behalf.

The Independent Engineer shall require the concessionaire to carry out or cause to be carried out tests to determine that such remedial measures have brought the construction works into compliance with the specifications and standards, and the procedure set forth in this clause shall be repeated until such construction works conform to the specifications and standards.

Therefore, we request that the field laboratory set up a concrete mix trail for RCC M-20 using the suggested cement.

Thank you, and we will always provide the best service.

[Yours,]

[Insert the name of the authorized person].

To

The Concessionaire,

Subject: Approval for M-20 Grade Cement Concrete Mix Design—Reg.

Dear Sir,

We looked over the test results for the compressive strength of M-20 grade cement concrete cubes (7 days) that were sent to us in the letter above and thought they were fine, meeting both MORT&H and AASHTO standards and requirements.

Therefore, we hereby approve the use of M-20-grade concrete in accordance with the mix design.

Thank you while ensuring our best services.

[Yours Sincerely,]

[Insert the name of the authorized person].

To

The Concessionaire,

Subject: Provisional acceptance for the use of concrete mix due to the urgency of the work—Reg

Dear Sir,

You have submitted the concrete mix design for M20-grade concrete for kerb-raising works. In addition to the results of a 7-day compressive test for approval to use this mix design, We examined the submitted concrete mix design and found it to be in compliance with these standards and requirements.

Given the urgency of the task, we hereby provisionally accept the mix design for use. After receiving satisfactory 28-day compressive test results, we have approved this mix design.

Please be aware that the acceptance of the mix design above is solely dependent on the specified sources of materials. However, in the event of any change in the material sources, the concessionaire shall obtain a fresh acceptance of the mix design from IE.

Thank you while ensuring our best services.

[Yours,]

[Insert the name of the authorized person].

To

The Concessionaire,

Subject: Observations on the Submission of Mix Design M20 Grade Concrete for Kerb Raising Works—Reg.

Dear Sir,

You have submitted the concrete mix design of M20 grade for permanent works, along with the results of the 7- and 28-day compressive tests, for approval to use this mix design. We examined the submitted concrete mix design and found it to be in compliance with standards.

We hereby accept the mix design for its intended purpose.

Please be aware that the acceptance of the mix design above is solely dependent on the specified sources of materials. However, in the event of any change in the material sources, the concessionaire shall obtain a fresh acceptance of the mix design from IE.

Thank you while ensuring our best services.

[Yours,]

[Insert the name of the authorized person].

To

The Authority/IE/AE/PMC,

Subject: Submission of RCC M30 Grade Mix Design Structure Works-Reg

Dear sir,

With reference to the above subject, we are submitting the concrete mix design RCC M30 Grade. We tested the concrete cubes for 7 days and have attached the test results herewith. We found that the test results align with the project specifications, LS 456:2000 (Amendment No. 5, July 2019).

Further, 28 days of testing will be conducted, and the results will be submitted. We need your prompt review and approval to proceed with the next steps.

Thank you while ensuring our best services.

[Yours,]

[Insert the name of the authorized person].

To

The Authority/IE/AE/PMC,

Subject: Submission of RCC M30 Grade Mix Design Structure Works-Reg

Dear sir,

Regarding the previously mentioned subject and reference (letter 8), we are providing the 28-day compressive strength test reports for the M30 Grade Mix Design. The test results align with the project specifications, specifically LS 456:2000 (Amendment No. 5, July 2019), for your review and approval.

Thank you while ensuring our best services.

[Yours,]

[Insert the name of the authorized person].

The Concessionaire,

Subject: Observations on the Submission of Mix Design RCC M30 Grade Concrete for Highway Works—Reg.
Dear sir,

This pertains to the topic mentioned above. You have submitted the RCC M30 grade concrete mix design for highway works. You have also submitted the 7-day compressive test results for approval to use this mix design.

We have examined the submitted concrete mix design as per the MORTH specifications. We found the submitted concrete mix design to be in compliance with the specifications and standards. The mix design as such is, at this moment, provisionally accepted for use due to the urgency of the work. This mix design was approved after the satisfactory 28th-day compressive test results were submitted.

Please be aware that the acceptance of the mix design above is solely dependent on the specified sources of materials. However, should the material sources change, the concessionaire must obtain a new approval of the mix design from IE. This is for your information, and we still need full action.

Thank you while ensuring our best services.

Yours
Insert the name of the authorized person

To

The Concessionaire,

Subject: Observations of Mix Design RCC M30 Grade 28-Day Compressive Strength Test Results—Reg.

Dear Sir,

This is with reference to the subject cited; you have submitted compressive strength test results for RCC M30 grade for 28 days, in continuation of the earlier submitted mix design for RCC M30 grade along with a 7-day report. We found the above-mentioned test report satisfactory, adhering to the specifications and guidelines of MoRT&H table 1700-5. As a result, final approval is granted for the use of RCC-M30-grade concrete in structural work.

Thank you while ensuring our best services.

[Yours,]

[Insert the name of the authorized person].

To

The Concessionaire,

Subject: Mix Design approval letter format—Reg.

Dear Sir,

With reference to your above letter and the document submitted by you, the same has been scrutinized by us and we would like to intimate you, that we have no objection if you use the following Concrete Mix Design.

This acceptance is on temporary basis, as you have to review the mixes continuously in presence of IE; representatives only.

 Thanking you,

[Yours,]

[Insert the name of the authorized person].

To

The Concessionaire,

Subject: Concrete Mix Design for Section-II.

Ref: Your Letter submission

Dear Sir,

With reference to your submissions related to the Concrete Mix Designs of M15,M20,M20(kerb), M25 Grades as per point No 1, schedule D, page 240 of concession agreement (i.e., it is that that Four-Laning of the Project Highway shall conform to the laning of Highways through Public Manual of Specifications and Standards for Four-Private Partnership published by the Planning Commission; Government of India) and clause 5.3.2 of Manual for specification and standards for four Laning of Highways( i.e., IRC SP 84 clause 5.3.2 Method of Design of Rigid Pavement

Rigid pavement shall be designed in accordance with the method prescribed in IRC: 58 “Guidelines for the Design of Plain Jointed Rigid Pavements for Highways”. We have reviewed the same and our comments as below.

1. 28 days Concrete cube strength results were not submitted.
2. As per your submitted report, fine aggregate 150 mic. Sieve analysis reports found out of limits.

Please submit your compliance for our final review.

Thanking you,

Ref: Your Letter Submission

Dear Sir,

With reference to your submissions related to the Concrete Mix Designs of M15,M20,M20(kerb), M25, M30,M35,M40 Grades as per point No 1, schedule D, page 240 of concession agreement and clause 5.3.2 of Manual for specification and standards for four Laning of Highways, we have reviewed the following list of concrete Mix designs..

1. You have to check the concrete mixes continuously in presence of IE’s representatives only.
2. You have to check the gradation and correction of moisture content for fine aggregate ie Crusher sand /coarse aggregates regularly in presence of IE’s representatives only.

This is for your information and compliance.

Thanking you,