Reconstruction methods of carriageway

Reconstruction methods of carriageway

Content Brief:

• Reconstruction methods of carriageway: This content pertains to the review and recommendations on flexible pavement carriageway reconstruction methods.
• It also highlighted the standard process involved in pavement reconstruction. Recommendations will be communicated to the concessionaire in a sample draft letter format.
• These recommendations are made by the IE following the concessionaire’s submission of pavement conditions survey data.
• Pavement conditions data is collected based on the following:

1. Physical visual inspection,
2. BI and BBD test results
3. Existing pavement crust thickness and its condition
4. And the existing pavement surface defects were identified during the site inspection.
5. Also, the data of locations where the profile corrections are warranted as per site requirement, i.e., water stagnation areas on pavement surface, etc.

The IE recommendations are summarized in this letter in the form of various cases. Such are

1. Case-1: Where cutting of existing CRB layer is less than 50 mm
2. Case-2: Where cutting of existing CRB is more than 50 mm
3. Case-3: Complete removal and reconstruction

   

Standard Process involves in pavement reconstruction of existing carriageway

• Flexible Pavement carriageway reconstruction involves the complete removal or partial removal and replacement of the existing pavement on a roadway. This process is useful when the existing pavement is severely damaged and deteriorated significantly.
• Flexible Pavement reconstruction typically involves the following steps:
• Completely remove the existing pavement
• Grading and levelled the excavated surface i.e., subgrade, or base layer of the pavement with appropriate cross fall or camber for proper drainage and to ensure a stable foundation for the new pavement.
• Construction of base and sub base layers as per new pavement crust
• Then construction of DBM and BC layers as per specified thickness and standards
• Finally, the new pavement is compacted with rollers, smoothing and levelling the surface, and applying any necessary markings or pavement striping.

A letter on review and recommendations on reconstruction methods of flexible pavement

To The concessionaire Subject: Reconstruction of existing carriageway-Reg. Dear Sir, In connection with the review of the existing carriageway of the Project Highway, we have completed our review based on our critical studies. Joint site inspections with Concessionaire EPC and PMC experts and scrutinizing the rutting pattern, BBD test results, and other aspects of the pavement condition survey, we recommend partial reconstruction for the following patches: Reconstruction Si. No From To Length(km) 1 0+000 4+100 4.100 -do- -do- -do- Note: This portion required complete reconstruction from subgrade bottom level. Reconstruction Si. No From To Length(km) 1 15+000 18+500 3.500 -do- -do- -do- Note: The above chainages locations are to be reconstruction for paved shoulder parts only. Methodology for Reconstruction Reconstruction methods of carriageway Case-1: Where cutting of existing CRB layer is less than 50 mm Remove the Existing BC Layer Loosening and re compaction of existing CRB top surface to be done as per MoRT&H Specification. Provide WMM with 250mm thickness on top of the compacted CRB layer as per the approved cross-section drawing. Provide full-thickness DBM and BC layers on top of the completed WMM layer as per approved pavement compositions. Reconstruction methods of carriageway Case-2: Where cutting of existing CRB is more than 50 mm Change FRL by rising as per requirement of case -1 above. In case raising of FRL is not possible due to any practical reason, then the following steps should be adopted: Remove the existing pavement up to the level of 100 mm at the at the bottom of the WMM of the widening portion. Loosening and recompaction of the layer are to be done as per MoRT&H technical specifications. Provide GSB, WMM, and DBM, BC layers as per the approved pavement compositions. Note: At least 100 mm of thickness of the new GSB layer should be laid in this case. Reconstruction methods of carriageway Case 3: Complete removal and reconstruction Remove the existing pavement up to formation level (top of proposed subgrade level). Loosening and re-compaction of the proposed formation level are to be done as per the requirements of MoRT&H technical specifications. Provide full thickness of GSB (200 mm), WMM (250 mm), DBM, and BC layers as per the approved pavement composition. Complete reconstruction for the patch within the chainage 109.300 to 110.200 from the bottom of the subgrade level of the existing carriageway. Reconstruction methods of carriageway: conclusion The instructions provided in this letter supersede all other instructions provided in the related previous letter, and you are being instructed to comply with our recommendations in all future reconstruction works. Thanking you,

Note to a visitor about the Reconstruction methods of carriageway

It is that a few important and mandatory aspects are only discussed herewith. Kindly note that the above inspection observations are considered examples. You may adopt the gist of the subject and change it to suit the current need. And before using this content in your letter drafting, you need to ensure the specific CA Contractual conditions and other aspects, etc.

It is suggested to read article about Review on major bridge GAD drawings on Highway project, Review observations on MNB drawings

Also, read about the highway Improper bituminous construction works and site Instruction on Dense bituminous concrete construction works. 

Additionally, you can find various sample draft formats for highway operation and maintenance correspondence.

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