i_ind m 02 eng eng 11 001 rev000 technical information concrete tower

Technical Information: Concrete Tower

ENERCON India Ltd Survey-33. Bhimpore, Daman Phone : +91-260-2220312 Fax : +91-260 2221218

Original Details Translation Details Compiled/Date : Anand Maharana/R. Prakash 11.10.2011 Checked/Date : Ajay Mathur / 11.10.2011 Revision : 000

Translated/Date : xxx / xxx Checked/Date : xxx / xxx Revision : 000

File Name : i_ind-m-02-eng-eng-11-001 Rev000 Form details : Rev 005 of 16

General:

This document gives information on Defects, Limit values and Action plans for Precast concrete tower.

This document to be followed along with other mentioned Technical Instructions / Information.






Sr. No.

Defect/ Flaw

Area/ Location Probable cause Limit Values Actions Plan

1

Crack

Surface crack at top of bottom segment door opening.

1. Stress concentration due to curvature.

2. Temperature variation.

Width: < 0.2 mm Length <200 mm. (There must not be any horizontal cracks of a Measurable width) If width found more than 2mm, immediately contact TSS.

1. Compliance to document “s-me-02-ger-eng-07-002 Rev000”.

2. Yearly monitoring of the crack in CT checking report s-me-03-ger-04- 013.

3. Cracks above specified limit, need to be repaired as per Annexure-1.

2

On grout.

1. Wrong mixture of grout components.

2. External environmental reactions.

3. Incorrect curing.

Width: < 0.3mm Length: > 50mm It is essential to close the observations within 6 months from the date of observations for the Durability reason.

1. Yearly monitoring of the crack in foundation checking report “s-m-03-eng-04-001”.

2. Filling of the cracks in the existing grouting with the help of Sikagrout 214 as per Annexure II.






Sr. No.

Defect/ Flaw

Area/ Location Probable cause Limit Values Actions Plan

3

Surface

Abnormalities

Spalling at the edges of the segments.

1. Pre stress after the grouting setting has been completed near to the edges.

1. Cumulative 10% of circumference.

2. Reinforcement shall not be exposed.

(Reinforcement will get exposed at @ 40mm depth)

1. Record in the checking report “s-me-03-ger-04-013”.

2. Repair instruction as per structural requirement and non structural requirements. (In consultation with Central TSS). Procedure described on Annexure III

4

Grout shrinkage

Visible reinforcement on precast concrete surface at LRPC 19th section.

1. Error in grout mix design i.e.- wrong proportion of sand, fly ash, cement and water mixture.

2. Poor workmanship / process.

There shall not be any visible cable of LRPC.

Re-grouting to be done with LRPC grout as per steps described on Annexure IV






Sr. No.

Defect/ Flaw

Area/ Location Probable cause Limit Values Actions required

5

Surface Abnormalities

Honey combs or Pores on segment surfaces.

1. Error in concrete mix

design i.e.- wrong proportion of sand, fly ash, cement and water mixture.

2. Production process error.

3. Trapped water / air.

1. Reinforce shall not be visible. 2. Diameter 8 mm or equivalent size and 5 mm depth not necessary to repair.

Sikadur paste to be used to fill the voids.

6

Hard top of foundation.

1. Error in concrete mix

design i.e.- wrong proportion of sand, fly ash, cement and water mixture.

2. Improper curing. 3. Damage by impact or

sharp object.

Needs to be filled if more than 20mm.

1. Clean the affected area for any dust or sand. 2. Filled with cement mixture and followed with standard curing procedure. (As per manufacturer’s specification).






Sr. No.

Defect/ Flaw Area/ Location Probable cause Limit Values Actions required

7

Misalignment/ offset of segments

Segment to segment joint. 1. Absent of dowel

pins during mounting.

Offset more than 10 mm is not allowed, if observed refer to TSS immediately.

1. Must be recorded

in LTF. 2. Case to case disposition will be carried out by Civil TSS members. CTF team shall review and dispose same.

8

Gap

Gap at concrete to concrete segments.

Insufficient application of the epoxy during erection.

Cumulative 300mm measurement in the circumferentially.

1. To be filled for structural repair with epoxy with special instruction. (By Special Team) 2. If less than 300mm then need to be filled with resin/ grout at site level from inside & outside.






Sr. No.


9

Damaged/ Slip Thread inserts

Damage / Injured thread inserts for connections of Ladder, Platform, Transformer, PE connections.

1. Production error, i.e.-

slender placed while casting process.

2. Stick of foreign particles i.e.- grout, sand, etc.

3. Over torque while assembling.

1. There should not be

any missing thread insert.

Retrofit threads insert with help of thread insert as per Annexure V.

10

Missing prestressing wires

19th steel section.

1. Prestressing wire

path obstruction. 2. Jacket tube shift

production process.

No missing LRPCs are allowed.

In case missing dynamic stability study to be carried and report to be submitted.






Sr. No.


10

Water ingress/ accumulation

In Basement

1. Percolation of

ground water. 2. Ingress from door.

PCC should at max. 1.5mt below ground level.

Water to be extracted with use of Pump.

11

Corrosion / White formation on steel tower assembly parts

Water formation on steel tower and concrete tower transition.

Rust formation / red patch on components.

1. Cleaning and

tactile application on hardware.

2. Replacement of hardware on red rust.






Sr. No.


12

Grout spread over outside

tower

1. Absent of seal on

jacket tubes. 2. Displaced seal

while erection / mounting.

3. Improper epoxy application.

There should not be any grout over outside.

1. Remove adhered

grout and rough the affected area.

2. Carry out PU paint application over effected area.

13

Misaligned / Un-torque Bolt joint

Transformer to tower structural joint

1. Structural alignment not done before fixing the same.

2. Negligence.

1. No loose joints acceptable.

2. All joints with the

gaps shall be corrected to have zero gaps at joint with specific torque value.

Making the structure load free by lifting the transformer and realignment of the structure for technical requirements as per protocol.






IMP Note

It applies to all Annexure listed below:

Ø Confirm of shelf life of all materials before use it.

Ø Follow manufacture’s instruction for preparing mixture / operating instruments.

Ø Follow safety instructions while working in & around of WEC.

Ø Wear safety equipments (Gloves, Goggle, Nose mask, etc.) as & when required.






Pic. - 03

Pic. - 05 Pic. - 06

Pic. - 02 Pic. - 01

Pic. - 04

Annexure I: Surface crack Repairing using Sikagrout 214

!!! IMP: During preparation steel reinforcement shall not be damaged.






Pic. - 08 Pic. - 07

Tools Required: Materials Required:

Procedure / Steps:

Sr. No. Materials SAP No. 1 Sikagrout 214 61792 2 Sikalatex Power 3 Cement OPC 53 grade 55648 4 Water

Sr. No. Tools SAP No. 1 Wire Brush 14890 2 Trowel 25539 3 Scrapper 18194

Sr. No.

Picture No. Description

1 1 to 3 Clean the surface by using of the wire brush & Make the V groove with help of carbide tip/ scraper, complete length and depth of crack developed and scrap the surface by use of the Scrapper.

2 4 Prepare the grouting concrete from Sikagrout 214 with water in the ratio of 2:1. 3 5 Prepare binding materials from the sika latex power, cement with water (as per requisite). 4 6 Fill the Groove with the binding material completely. 5 7 Fill Groove with using the grouting concrete. 6 8 Leave repaired area for curing (approximate 10 hrs).






Pic.01 Pic.01 Pic.02

Annexure II: Grouting crack Repair using Sikagrout 214 Pic 1 and 2 shows the situation - Before Repair - After repair in case crack found in the foundation surface in 1 D grouting area.


Procedure / Steps:

Sr. No. Tools SAP No.

1 Wire Brush 14890 2 Trowel 25539 3 Scrapper 18194 4 Tin Applicator 89171

Sr. No. Materials SAP No.

1 Sikagrout 214 61792 2 Sikalatex Power

3 Sikadur 31 (Comp A & B) 55397 4 Cement OPC 53 grade 55648

Sr.No. Description

1 Clean the surface by using of the wire brush & Make the V groove with help of Scrap on crack surface by using of the Scrapper and Clean the surface with the water.

2 Prepare binding materials from sika latex power, cement with water. 3 Prepare grouting concrete by using of the Sikagrout 214 with water in ratio of 2:1. 4 Initial fill the Grooves with the binding material completely by using trowel or suitable medium. 5 Then fill the groove with grout concrete. Leave it for cure.

6 After 6 Hours apply the Sikadur 31 paste on repaired surface with help of tin applicator. Prepare Sikadur 31 paste as per manufacturer instruction.






Pic. - 01 Pic. - 02 Pic. - 03

Pic. - 04 Pic. - 05 Pic. - 06

Annexure III: Spalling repair






Tools: Materials:

Procedure:

Sr. No. Materials SAP No. 1 Sikagrout 214 61792 2 Sikalatex Power 3 Cement 55648

4 Water

5 Separol sika 79345 6 Antisol sika 78345

Sr. No. Tools SAP No.

1 Wire Brush 14890 2 Trowel 25539 3 Scrapper 18194 4 C- Clamp 5 Shuttering Sheet 6 Paint Brush 7 Wooden blocks

Sr. No. Picture No. Description

1 1 Clean the surface with use of wire brush, rough area with chiesel and then wet the affected surface.

2 Prepare binding compound on mixing Sika latex Power, cement, water as per requirement. 3 2 Apply the binding compound on affected surface with brush.

4 3 Cover the affected area with help of shuttering sheet and C – Clamp. Before that apply shuttering oil all over shuttering sheet for avoiding contact to concrete.

5 4,5,6 Prepare the Grouting Concrete mix with Sikagrout 214 and water at ratio of 2:1 and then pour the concrete inside affected area. During pouring lightly impact on plate to accommodate concrete.

6 Leave repaired area to cure for 10 Hours then remove the shuttering plate and apply the curing compound antisol sika on the surface.






Pic. - 01 Pic. - 02 Pic. - 03 Pic. - 04

Annexure IV: Re – grouting of Prestressing rope Caps


Procedure / Steps:

Sr. No. Materials SAP No. 1 Sikagrout 214 61792 2 Cement 55648 3 Water

Sr.No. Tools SAP No.

1 Stirrer machine 26254 2 Trowel 25539

Sr. No. Pict.No. Description

1 1 Clean exiting cap inside cap for loose material and chips. Check LRPC cables and the caps for deformations. Incase caps are damaged replace with new one.

2 2 & 3 Prepare grout material from Sikagrout 214 cement and water mix in ratio 2:1. Mix the component with stirrer machine. Mixture should be consumed with in 10 minutes. Check for suitability for preparation at bottom or top.

3 Pour the concrete mixture in the caps till top edge of cap.

4 4 After 24 hrs check the height of the concrete grout and re-grout the same if required. Low level after curing may appear due to shrinkage.






Annexure V: Anchor bolt fastening for the ladder mounting in case of thread damage of RD 16.

Sr. No. Pic. No. Description 1 1 Drill a hole of Ø16mm till 85 mm depth at required location (Within 100 – 200 mm from damaged threads and with

reference to available provision i.e.- ladder, U-bracket, etc.) 2 2 Remove concrete chips and powder with help of air blower from the drilled hole. 3 3 Insert fischer bolt of M16 x 110 and length, as per recommended, with help of nylon mallet. 4 4 Then fix U-bracket and torque hardware with 100 NM (as per torque table of fischer bolt manufacturer) 5 5 Complete assembly of the Bolt restored bolt connection.

Pic. - 01 Pic. - 02 Pic. - 03

Pic. - 05

Pic. - 04

Pic. – 06 – details anchor bolt Fischer

i_ind m 02 eng eng 11 001 rev000 technical information concrete tower

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