Structure and Tunnels Investment Portfolio 2 · 2020-01-28 · requirements of BS1881: Part 204:1988. Cover measurements were recorded using an electromagnetic cover meter at each

Revision P01 – Final for Comment

Document Ref: ST130010-WSP-STR-ZZ-RP-ST-1701Date: January 2016

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Structure and TunnelsInvestment Portfolio 2A40 Westway Information Centre –Concrete Investigation Special Inspection

Transport for London

Q u a l i t y M a n a g e m e n tDocument Title: A40 Westway Information Centre – Concrete Investigation Special Inspection

Document Ref: ST130010-WSP-STR-ZZ-RP-ST-1701 Rev P01

ISSUE/REVISION: A

Remarks Final draft for clientcomment

Date 19/01/2015

Prepared by

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Checked by

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Approved for issue

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Structure and Tunnels Investment Portfolio 2 WSP | Parsons BrinckerhoffTransport for London Report Ref: ST130010-WSP-STR-ZZ-RP-ST-1701 Rev P01

January 2016

Executive SummaryWSP|Parsons Brinckerhoff was commissioned by TfL to undertake a Concrete InvestigationSpecial Inspection of the Westway Structure within the boundaries of the Westway InformationCentre premises.

The purpose of the Special Inspection was to gain an increased understanding of the overallcondition of the supports 121 – 125 and their bearings, along with the adjacent deck soffit.

The Special Inspection was undertaken on the 21st and 22nd October 2015 and comprised bothvisual inspection and concrete testing works. A total of sixteen test areas were conducted to thesupports 122 - 125, four to each support. At each support three test areas were located at thecrossheads with one located to the top of a pier wall. The Special Inspections identified thefollowing:

Concrete Testing:

The results of the concrete investigations indicate that chloride induced corrosion of reinforcementis likely at areas of the crossheads that are subjected to leakage. One area of leakage was foundto have reinforcement suffering from early stages of pitting corrosion, with only minor loss ofsection found.

Supports:

The supports, in particular the crossheads, are affected by localised areas of leakage, consideredto originate through the deck joints above. As discussed above, this has caused localisedchloride ion contamination of the concrete and subsequent initiation of pitting corrosion ofreinforcement.

It is a concern that areas of the supports have been cut out to facilitate access/services. Althoughthe surrounding areas are showing no signs of distress at this time, the effects of the removal ofthe concrete should be assessed to determine whether they are likely to be significant, or thepiers reinstated to their original condition.

Support Bearings:

Although minor defects were observed to a small number of bearings, including bulging andcompression, these defects are not considered to be significant or affecting their durability.

Deck Beams:

A small number of deck beams have been affected by leakage through weep pipes installedbetween the beams. It is possible that this has caused chloride contamination of the affectedconcrete, however this could not be determined during the investigations as concrete testing wasnot undertaken in these locations.

There are a number of fixtures and fittings attached to the deck beams. It appears that thesehave been hung from the top face of the bottom flanges and do not appear to be causing damageor distress to the beams.

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In order to maintain the serviceability of the supports, their bearings and the deck beams of theA40 Westway within the confines of the Information Centre premises, the followingrecommendations are made:

· Leaking deck joints above the supports are replaced to prevent further leakage andconcrete contamination.

· The current water management system should be reviewed with a view of removing theguttering that has been fixed to the crossheads. The matting and the adhesive should beremoved to enable a complete inspection of the obscured concrete. The weep pipesthrough the deck beams should be extended to clear the beams and should beincorporated into a new and effective water management system.

· All areas of the supports that have been cut out should be reinstated unless assessmentconfirms that they have not caused detrimental effects to the structure.

· Removal of obsolete and unnecessary fixtures and fittings from the deck beams.· Removal of birds’ nests and other debris from the top of the supports.


January 2016

ContentsExecutive Summary ....................................................................................... i

1 Introduction ........................................................................................... 1

2 Structure Information ........................................................................... 22.1 Location and General Description .................................................................... 2

3 Testing Criteria ...................................................................................... 33.1 Site Testing Criteria ......................................................................................... 3

3.2 Laboratory Testing Criteria .............................................................................. 4

4 Inspection Summary ............................................................................. 54.1 Overview ......................................................................................................... 5

4.2 Concrete Testing Results ................................................................................ 5

4.3 Visual inspection ............................................................................................. 6

5 Conclusion............................................................................................. 85.1 Concrete Testing ............................................................................................. 8

5.2 Supports ......................................................................................................... 8

5.3 Support Bearings ............................................................................................ 8

5.4 Deck Beams.................................................................................................... 8

6 Recommendations ................................................................................ 9

Appendix I – Sketches

Appendix II – Factual Testing Report and Laboratory Test Results 2015

Appendix III – Photographs

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1 IntroductionWSP|Parsons Brinckerhoff were commissioned by TfL to undertake a Concrete InvestigationSpecial Inspection of the Westway Structure within the boundaries of the Westway InformationCentre premises.

The purpose of the Special Inspection was to obtain an increased understanding of the overallcondition of the supports 121 – 125 and their bearings, along with the adjacent deck soffit.

Concrete investigation works were undertaken in accordance with the requirements of HighwaysAgency Design Manual for Roads and Bridges (DMRB) standard BA 35/90 – Inspection andRepair of Concrete Highway Structures. The scope of concrete investigation works included;

· Reinforcement cover measurements;· Delamination / hammer-tap survey;· Half-cell potential measurements;· Concrete resistivity measurements;· Depth of carbonation;· Chloride ion content testing.

The Special Inspection also included a visual inspection of all accessible parts of the structurewithin the confines of the Westway Information Centre premises including;

· Bearings;· Crossheads;· Piers;· Bridge soffit.

The findings of the concrete testing works are summarised in this report, in-situ and laboratorytest results can be found in Appendix II.

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2 Structure Information2.1 Location and General Description

Figures 1 shows the location of the A40 Westway. The A40 Westway is a major structure on astrategic route into central London and is made up of 52 individual structures along 4.6km oflargely elevated road between Wood Lane Flyover to the west and Marylebone Flyover to theeast. The structures are predominately of concrete construction with a mixture of pre-stressedand post tensioned decks. The structures were built in the late 1960s and 70s.

The Westway Information Centre is located within Section 4, immediately east of Ladbroke Grove.

Figure 1 – Location plan

WestwayInformationCentre

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3 Testing Criteria3.1 Site Testing Criteria

Concrete testing works to specified targeted crossheads and pier concrete locations on the A40Westway was undertaken in accordance with:

(i) TfL document titled “STIP 2 Westway – Stage 1, Scope of Work for TargetedInvestigations”, document reference ST130013-AMD-STR-ZZ-EP-KC-0001 datedJuly 2015.

(ii) TfL document titled “Scope for prioritisation of STIP2 Programme, Completion ofStage 1 & SI’s of Vacant Premises”, document reference ST130010-AMD-STR-ZZ-EP-KC-0006.

(iii) DMRB standard BA 35/90 – Inspection and Repair of Concrete HighwayStructures.

(iv) The following testing, analysis, and reporting criteria.

3.1.1 Reinforcement Cover Measurement

Cover meter surveys in accordance with the requirements of clause 7.3.1 of BA 35/90 and therequirements of BS1881: Part 204:1988. Cover measurements were recorded using anelectromagnetic cover meter at each node of a test panel grid with nodes set at regular intervals.The cover meter was checked by direct measurement to the reinforcement exposed for half-cellpotential connections.

3.1.2 Delamination (hammer tap) surveys

Delamination (hammer tap) surveys in accordance with the requirements of clause 5.2.5 of BA35/90. The survey areas included all areas of the piers and crossheads and the adjacent areas ofthe deck soffit (reachable from scaffold set up at pier locations).

3.1.3 Half-Cell Potential Measurements

Half-cell potential surveys in accordance with clause 7.3.3 of BA 35/90 and ASTM C876-09 -Standard Method for Half-cell Potentials of Uncoated Reinforcing Steel in Concrete. Thefollowing potential boundaries were considered in the testing works:

· Where potentials are less negative than -200 mV (CSE) there is less than 10 %probability that corrosion of reinforcement is occurring.

· Where potential measurements are in the range -200 mV and -350 mV (CSE)corrosion activity is uncertain.

· Where potential measurements are more negative than -350 mV (CSE) there is a90 %, or greater, probability that corrosion is occurring.

The results from the half-cell potential surveys were combined with the results of the chloride ioncontent testing to determine the likely corrosion risk at each test location, as Figure A1.1 of DMRBstandard BD 43/03.

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3.1.4 Concrete Resistivity Measurements

Concrete resistivity surveys were undertaken using a Scribe 2 probe meter in accordance withclause 7.3.4 of BA 35/90 and Technical Guide 2 – Guide to Testing and Monitoring the Durabilityof Concrete Structures. Measurements record the magnitude of the corrosion current to identifythe corrosion potential in conjunction with results from half-cell potential measurements andchloride ion content testing. The following resistivity boundaries were considered in the testingworks:

a) If the resistivity is greater than 12 kΩ cm, corrosion is unlikely to occur.

b) If the resistivity is in the range 5-12 kΩ cm, corrosion will probably occur.

c) If the resistivity is less than 5 kΩ cm, corrosion is almost certain.

Results from the resistivity surveys were combined with the readings from the half-cell potentialsurveys to give an indication of the likelihood and rate of reinforcement corrosion

3.1.5 Depth of Carbonation

Measurement of depth of carbonation of the concrete, using phenolphthalein as an indicator, wasundertaken in accordance with clause 7.2.5 of BA 35/90 and Test Procedure TP/STRUCT 04(which is based on BRE Information Paper 6/81).

3.2 Laboratory Testing Criteria

3.2.1 Chloride Ion Content Testing

Recovery of concrete dust samples was undertaken to enable off-site laboratory testing (by aUKAS accredited laboratory, Nicholls Colton) of the chloride ion content within the concrete.Testing concentrated on elements subjected to direct saturation with salt laden water i.e. thoseelements subject to direct run-off from defective expansion joints and highway drainageinfrastructure above. The recovery and testing of dust samples was undertaken in accordancewith clause 7.3.2 of BA 35/90 and BS 1881: Part 124:1998.

Dust samples were recovered from varying cover depths to measure the depth of contaminationof the concrete cover and whether the chloride ion content at the level of the reinforcement is acause for concern.

Results of the chloride ion testing are to be considered in conjunction with the results of the half-cell potential and concrete resistivity measurements to give an overall picture of the corrosion risk.Chloride ion contents of 0.3% by mass of cement is considered to be the threshold above whichpitting corrosion may be initiated.

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4 Inspection Summary

4.1 OverviewThe Special Inspection was undertaken on the 21st and 22nd October 2015. Access within theWestway Information Centre premises was facilitated by ARJ Construction and access to thebridge crossheads and top of piers was achieved using mobile scaffold towers. A total of sixteentest areas were conducted to the supports 122 - 125, four to each support. At each support threetest areas were located at the crossheads with one located to the top of a pier wall.

The weather conditions during the inspections were typically dry with occasional light showers.See Appendix II for concrete investigation location plans.

A visual inspection was undertaken to all elements within the boundary of the WestwayInformation Centre premises, which included the deck beams of spans 72 – 75, supports 122 –125 and their bearings. Only the west face of support 125 was accessible due to the presence ofthe boundary wall with the neighbouring property. Support 121 was outside the boundary of theWestway Information Centre premises (Photograph 1) and therefore no works were undertakenon this.

4.2 Concrete Testing ResultsThe Factual Testing Report and the Laboratory Testing Results are included in Appendix II andare summarised below:

· Areas subjected to leakage to the west face of crossheads 123 & 124 (Test Areas T5 &T9) are currently considered to be in ‘FAIR’ condition in accordance with Figure A1.1 ofBD 43/03. Chloride content results for these areas were significantly above the thresholdlevel of 0.3% by mass of cement beyond the depth of reinforcement. A reinforcementexposure undertaken within Test Area T9 confirmed that the reinforcement had surfacecorrosion at worse, and there was no evidence of pitting corrosion (Photograph 3).

· A localised area of crosshead 125 (within Test Area T15) is considered to be in ‘POOR’condition in accordance with Figure A1.1 of BD 43/03. The chloride content valuesobtained ranged from 12.8% to 1.57% by mass of cement for the 4 incremental depths,where 0.3% is a conservative threshold level for the avoidance of pitting corrosion ofreinforcement. The sample demonstrated that the concrete contained very high chlorideion concentrations beyond the depth of reinforcement and half-cell potential resultsindicated there was a 90% probability that corrosion was occurring. A reinforcementexposure within this location confirmed the initiation of pitting corrosion - approximately10% loss of section was observed to the exposed bar (Photograph 4).

· The remaining areas tested are currently considered to be in ‘GOOD’ condition inaccordance with Figure A1.1 of BD 43/03, with all chloride levels below the thresholdlevel.

· Concrete resistivity measurements to all areas tested were well above the lower thresholdvalue for initiation of pitting corrosion indicating that active corrosion is currently unlikely.

· Concrete de-passivation due to carbonation had penetrated to a depth of less than 5mm,well short of the mean depth of reinforcement. Carbonation induced corrosion would notbe expected to occur in the crossheads in locations of un-cracked concrete.

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· Cement content results were broadly in line with what might be expected for a structure ofthis type and age, and do not give rise for concern.

4.3 Visual inspectionThe visual inspection found the supports, bearings and deck beams to be in overall goodcondition with no signs of failure evident. Specific defects observed are discussed in more detailbelow with the defect location diagrams included in Appendix I.

4.3.1 Supports

There were drainage channels (guttering) fixed to the top of the crossheads. Above this is whatappeared to be a matting fixed to the concrete with a resin/adhesive (Photograph 5). It isassumed this had been fitted in order to divert the flow of leakage from the crosshead concreteinto the guttering. The presence of this matting, and the large areas of resin/adhesive above,concealed large areas of the crosshead concrete, potentially masking defective areas.

There were localised areas of leakage with associated corrosion staining to the crossheads(Photograph 6). In certain locations this had emanated below the matting, indicating a localisedfailure of this retrospectively fitted protection system. It appears that this leakage originated at theend of the deck beams, suggesting failure of the deck joints above (Photograph 7).

It was evident that sections of the pier had been cut out to facilitate installation of emergencyaccess doors and ducting for services (Photograph 8, Photograph 9, Photograph 10 andPhotograph 11). A doorway appeared to have been cut out of support 122 and subsequentlybricked up, with only a small opening remaining, presumably for services (Photograph 12 andPhotograph 13).

A number of disused birds’ nests were present to the top of the crossheads (Photograph 14).

4.3.2 Support Bearings

The bearings appeared to be relatively new and the vast majority were found to be in goodcondition. However there were a small number of bearings that showed minor signs of slightdistress, including minor bulging and localised compression (Photograph 15, Photograph 16) –these observations do not give rise to concerns for the overall performance of the bearings and itis not considered necessary to replace these in advance of any other bearing replacementscheme.

Some of the concrete bearing plinths have corrosion staining. These are located at areas ofleakage mentioned above (Photograph 17).

Vertical cracking was observed to four concrete bearing plinths, with the cracking extending intothe pier crossheads. These were located to supports 122, below beams 9 & 12 east face; andsupport 124 below beam 17 west face and beam 14 east face. (Photograph 18, Photograph 19,Photograph 20). It is considered likely that the cracking originated due to drying shrinkage and isno indication of overstress or structural inadequacy of the bearing arrangement / plinth.

Many of the concrete bearing plinths appeared to be poorly compacted or constructed, withirregularly formed edges. It is likely that the plinths were formed by hand using proprietary mortarat the time of bearing pad placement, the surface finish to the edges of the plinths would not be astructurally important issue provided that the edges of the bearings were adequately supported.(Photograph 21, Photograph 22).

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Timber shuttering has been left in place on top of the supports behind many of the bearings. Thisappears to be wet in places, indicating leakage through the deck joints. (Photograph 23).

There were areas of debris to the top of the supports. This was observed to be worse to the westside of support 122 (Photograph 24).

From floor level it appeared that there is corrosion staining around a number of bearings, howevercloser inspection found it to be adhesive, or similar, assumed to be used during the bearinginstallation. (Photograph 18, Photograph 20).

4.3.3 Deck Beams

There were a number of localised areas of water leakage and staining onto the deck beamsoriginating from the weep pipes located between the beams. Some of the pipes are intended todrain directly into guttering hung from the beams, however the length of the weep pipes were insome locations too short to clear the beams. (Photograph 25, Photograph 26, Photograph 27,Photograph 28).

There are a number of fixtures and fittings attached to the deck beams (Photograph 28). Itappears that these have been simply lodged onto the top face of the bottom flanges, however thisarrangement could not be confirmed for all fixings during the inspection.

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January 2016

5 Conclusion5.1 Concrete Testing

The results of the concrete investigations, discussed in Section 4.2, indicate that chloride inducedcorrosion of reinforcement is likely at areas of the crossheads that are subjected to leakage. Onearea of leakage was found to have reinforcement suffering from pitting corrosion however onlyminor loss of section was observed at this time.

5.2 SupportsThe supports, in particular the crossheads, are affected by localised areas of leakage, consideredto originate through the deck joints above. As discussed in Section 5.1, this has caused localisedchloride ion contamination of the concrete and subsequent initiation of pitting corrosion ofreinforcement in certain locations. The corrosion of reinforcement was not severe at the time ofinspection.

It is a concern that areas of the support piers have been cut out to facilitate access/services.Although the surrounding areas are showing no signs of distress at this time (cracking adjacent tothe openings etc.), the removal of sections from the leaf piers could affect the overall stability ofthe structure under full loading. The effects of the modifications to the substructure should beassessed.

The cracking observed in the substructure is considered likely to be related to drying shrinkageand consequently is not cause for concern.

5.3 Support BearingsAlthough minor defects were observed to a small number of bearings, these defects are notconsidered to be significant or affecting their durability.

5.4 Deck BeamsA small number of deck beams are affected by leakage through weep pipes between the beams.It is possible that this has caused chloride contamination of the affected concrete, however thiscould not be determined during the investigations as concrete testing was not undertaken in theselocations.

The fixtures and fittings attached to the deck beams do not appear to be causing damage ordistress to the beams.

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6 RecommendationsIn order to maintain the serviceability of the supports, their bearings and the deck beams of theA40 Westway within the confines of the Information Centre premises, the followingrecommendations are made:

· Leaking deck joints above the supports are replaced to prevent further leakage andconcrete contamination.

· The current water management system should be reviewed with a view of removing theguttering that has been fixed to the crossheads. The matting and the adhesive should beremoved to enable a complete inspection of the obscured concrete. The weep pipesthrough the deck beams should be extended to clear the beams and should beincorporated into a new and effective water management system.

· All areas of the supports that have been cut out should be reinstated unless assessmentconfirms that they have not caused detrimental effects to the structure.

· Removal of obsolete and unnecessary fixtures and fittings from the deck beams.· Removal of birds’ nests and other debris from the top of the supports.

It would be prudent to monitor the following defects during future inspections:

· Cracking to the crossheads.· Minor defects to the bearings including bulging and localised compression.

Appendix ISKETCHES INCLUDING;Referencing DrawingDefect sketchesTest area locations

Project Number: Revision:

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TRANSPORT FOR LONDON

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Appendix IIFACTUAL TESTING REPORT AND LABORATORY TEST RESULTS

WSP |Parsons Brinckerhoff LimitedStructures Investigation GroupThe ForumBarnfield RoadExeterEX1 1QRTel: +44 (0) 1392 229700Fax: +44 (0) 1392 229701

FACTUAL TESTING REPORT

* INDICATES VALUES OBTAINED USING UKAS PROCEDURES.- INDICATES UNOBTAINABLE READINGS.FOR TEST AREA LOCATIONS REFER TO DRAWING NUMBER ST130010-WSPSTR-ZZ-RP-ST-1701-04 Sheets 2 TO 5

Page 1 of 18

G:\Projects\SIG\STIP 2\Westway Information Centre Testing\Report stuff\App II - 1 FTR SC reviewed.docx

Client: Transport for London (TfL)Client Address: Palestra House, 197 Blackfriars House, London, SE1 8NJReport No: WSP|PB/3514594A-SSR/FTR/01Project: Westway Information Centre Pier Crosshead Special InspectionDate of Site Works: 21 & 22 October 2015Report Date: November 2015

Parsons Brinckerhoff Limited were instructed by Transport for London to undertake a SpecialInspection of Westway Viaduct in accordance with the requirements of BA 35/90 - 'Inspection andRepair of Concrete Highway Structures'

Results are obtained in accordance with the procedures included in PB’s scope of accreditation asfollows:

Cover Measurements - BS 1881:Part 204:1988 - Recommendations on the use ofElectromagnetic Cover Meters.

Half-Cell PotentialMeasurements

- ASTM C876-09 (2009) - Standard Test Method for CorrosionPotentials of Uncoated Reinforcing Steel in Concrete.

NB. – Half-cell Potential measurements have been obtainedusing a digital Half-cell Unit (DHC) with a separate Silver/SilverChloride/Sat KCI electrode. The DHC unit converts readings toCSE equivalent values.

Resistivity Measurements - WSP|Parsons Brinckerhoff’s in-house procedures.

Prepared By: Date: 09/11/2015 Signed:

Checked By: Date: 19/11/2015 Signed:

Approved By: Date: 19/11/2015 Signed:

FIELD AND LABORATORY TEST RESULTS

* INDICATES VALUES OBTAINED USING UKAS PROCEDURES.** VALUES OBTAINED BY NICHOLLS COLTON, A UKAS ACCREDITED TESTING LABORATORY- INDICATES UNOBTAINABLE READINGS.FOR TEST AREA LOCATIONS REFER TO DRAWING NUMBER ST130010-WSPSTR-ZZ-RP-ST-1701-04 Sheets 2 TO 5

Page 2 of 18


STRUCTURE NAME/ROUTE: A40 Westway DATE: 21/10/2015

ELEMENT: Support 122, Crosshead WEATHER/TEMP: Dry / 14.0 °C

POSITION/ORIENTATION: West Face, Below Beams 10/11 TEST AREA REFERENCE: T1

A B C D E1 18 26 20 21 11

2 22 25 20 23 23

3 10 21 20 22 23

* COVER MEASUREMENTS (mm)

A B C D E1 22 52 -2 -4 85

2 9 63 5 19 27

3 63 159 2 12 15

* HALF-CELL POTENTIAL MEASUREMENTS mV (CSE)EXCLUDING TEMPERATURE CORRECTION VALUE OF -7.38 mV (CSE)

Grid Size: 500mm Longitudinally, 150mm Transversely

DESCRIPTION COVER HALF-CELLNo. OF READINGS 15 15

å OF READINGS 305 -1228

MINIMUM NUMBER 10 -121

MAXIMUM NUMBER 26 42

MEAN NUMBER 20 -82

No. £ 50mm 15

% £ 50mm 100

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.

**CHLORIDE ION CONCENTRATIONS(% BY MASS OF CEMENT)

CARBONATIONMEASUREMENTS

* RESISTIVITYMEASUREMENTS

5-30 30-55 55-80 80-105 mm Kohm cmD1 0.25 0.09 0.12 0.09 0-5 104.9



Page 3 of 18




POSITION/ORIENTATION: Soffit, Below Beams 4/5 TEST AREA REFERENCE: T2

A B C D E1 29 32 42 25 37

2 29 25 34 38 35

3 30 31 36 39 26


A B C D E1 151 146 158 161 158

2 130 159 149 147 140

3 -60 7 -77 -92 -95




å OF READINGS 488 1182



MEAN NUMBER 33 79

No. £ 50mm 15

% £ 50mm 100

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cmD3 0.13 0.11 0.08 0.09 0-5 135.3



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ELEMENT: Support 122, Pier Wall WEATHER/TEMP: Dry / 14.0 °C

POSITION/ORIENTATION: East Face, Below Beam 6 TEST AREA REFERENCE: T3

A B C1 57 53 57

2 - 82 67

3 52 72 53

4 47 39 32

5 - 58 61


A B C1 -81 -49 -44

2 -65 -86 -63

3 54 8 64

4 110 119 45

5 56 5 61







MEAN NUMBER 56 9

No. £ 50mm 3

% £ 50mm 23

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cmB2 0.11 0.08 0.09 0.23 0-5 135.1



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POSITION/ORIENTATION: East Face, Below Beams 12/13 TEST AREA REFERENCE: T4

A B C D E1 57 55 55 54 64

2 55 46 50 53 48

3 57 34 32 40 37

4 46 43 38 40 38


A B C D E1 140 138 141 98 136

2 139 153 157 84 127

3 152 153 148 143 143

4 136 111 160 132 142





MINIMUM NUMBER 32 84


MEAN NUMBER 47 137

No. £ 50mm 12

% £ 50mm 60

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cmB4 0.10 0.10 0.07 0.10 0-5 135.6



Page 6 of 18




POSITION/ORIENTATION: West Face, Below Beams 9/10/11 TEST AREA REFERENCE: T5

A B C D E F1 55 57 54 58 49 55

2 58 56 53 56 54 58


A B C D E F1 -153 25 8 -47 80 -153

2 -72 56 70 -69 99 -72







MEAN NUMBER 55 0

No. £ 50mm 1

% £ 50mm 10

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cm

A1 0.84 0.51 0.43 0.41 0-5 42.3



Page 7 of 18





A B C D E1 48 27 27 40 34

2 43 28 31 39 36


A B C D E1 -27 -29 -25 -22 -21

2 -2 -17 -30 -27 -31






MAXIMUM NUMBER 48 -2

MEAN NUMBER 35 -23

No. £ 50mm 10

% £ 50mm 100

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cm

E2 0.07 0.06 0.21 0.06 0-5 132.1



Page 8 of 18





A B C D E1 39 36 38 40 43

2 39 37 38 34 34


A B C D E1 -32 -37 -24 -34 -22

2 -41 -33 -23 -29 -24






MAXIMUM NUMBER 43 -22

MEAN NUMBER 38 -30

No. £ 50mm 10

% £ 50mm 100

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cm

A2 0.07 0.04 0.11 0.06 0-5 129.8



Page 9 of 18




POSITION/ORIENTATION: East Face, Below Beam 6 TEST AREA REFERENCE: T8

A B C1 60 56 49

2 40 46 43

3 45 46 47

4 39 35 41

5 42 40 39


A B C1 82 2 18

2 -65 54 28

3 -22 99 85

4 66 49 78

5 8 43 64







MEAN NUMBER 45 39

No. £ 50mm 13

% £ 50mm 87

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cmA2 0.07 0.07 0.07 0.07 0-5 79.6



Page 10 of 18





A B C D E1 44 44 44 43 44

2 51 47 49 48 45


A B C D E1 104 -186 72 70 -293

2 118 -99 111 58 -288







MEAN NUMBER 46 -33

No. £ 50mm 9

% £ 50mm 90

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cm

A5 0.98 0.57 0.35 0.17 0-5 42.2



Page 11 of 18





A B C D E1 24 17 25 26 38

2 27 26 36 27 42


A B C D E1 155 145 148 149 167

2 156 145 147 150 166







MEAN NUMBER 29 153

No. £ 50mm 10

% £ 50mm 100

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cm

B2 0.05 0.07 0.06 0.07 0-5 66.7



Page 12 of 18





A B C D E1 29 22 23 23 25

2 23 17 21 23 26


A B C D E1 165 169 149 179 179

2 181 170 140 179 183







MEAN NUMBER 23 169

No. £ 50mm 10

% £ 50mm 100

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cm

C2 0.08 0.06 0.07 0.06 0-5 69.1



Page 13 of 18




POSITION/ORIENTATION: West Face, Below Beam 6 TEST AREA REFERENCE: T12

A B C1 75 86 81

2 67 67 68

3 64 69 74

4 56 51 49

5 60 55 50


A B C1 109 125 136

2 69 62 89

3 9 79 -24

4 60 -57 -22

5 95 17 54







MEAN NUMBER 65 53

No. £ 50mm 2

% £ 50mm 13

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cmB4 0.08 0.12 0.09 0.09 0-5 135.1



Page 14 of 18





A B C1 66 54 76

2 33 45 44

3 52 53 48

4 41 39 68

5 31 37 50


A B C1 -73 -97 143

2 -72 -84 53

3 -66 -47 117

4 -77 -58 146

5 -101 -106 139







MEAN NUMBER 49 -12

No. £ 50mm 9

% £ 50mm 60

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cmA5 0.17 0.13 0.09 0.09 0-5 129.8



Page 15 of 18





A B C D E F1 43 48 46 49 57 43

2 42 45 46 48 62 42

3 35 44 46 48 60 35


A B C D E F1 159 180 182 159 183 159

2 162 177 178 167 186 162

3 165 174 177 178 177 165







MEAN NUMBER 48 174

No. £ 50mm 12

% £ 50mm 80

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cmD1 0.14 0.04 0.05 0.05 0-5 134.9



Page 16 of 18





A B C D E1 58 57 50 49 48

2 56 58 58 47 50


A B C D E1 -442 -132 45 131 -42

2 -381 -65 -15 182 -39







MEAN NUMBER 53 -76

No. £ 50mm 5

% £ 50mm 50

No. £ -350 mV (CSE) 2

% £ -350 mV (CSE) 20

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cm

A1 See T15 (SG) for results



Page 17 of 18




POSITION/ORIENTATION: West Face, Below Beam 11 TEST AREA REFERENCE: T15 (Small Grid)

A B C D E1 -449 -442 -440 -416 -167

2 -454 -444 -441 -183 -90

3 -449 -437 -420 -140 -137



DESCRIPTION COVER HALF-CELLNo. OF READINGS - 15

å OF READINGS - -5109

MINIMUM NUMBER - -454

MAXIMUM NUMBER - -90

MEAN NUMBER - -341

No. £ 50mm -

% £ 50mm -

No. £ -350 mV (CSE) 10

% £ -350 mV (CSE) 67

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cmA2 12.80 5.36 4.15 1.57 0-5 29.2



Page 18 of 18





A B C D E1 50 57 58 56 54

2 56 51 53 48 50


A B C D E1 183 186 118 151 121

2 233 177 163 181 136







MEAN NUMBER 53 165

No. £ 50mm 3

% £ 50mm 30

No. £ -350 mV (CSE) 0

% £ -350 mV (CSE) 0

GRIDREF.




5-30 30-55 55-80 80-105 mm Kohm cm

C2 0.08 0.06 0.06 0.30 0-5 135.7

Issued by JG 03.12.13; Authorised by MS UNCONTROLLED DOCUMENT IF PRINTED G:\Nicholls Colton Analytical\Controlled Documents\Report Templates\1881\1881 Cement.doc

Nicholls Colton & Partners Limited

7-11 Harding Street, Leicester, LE1 4DH

Tel: 0116 253 6333. Fax: 0116 251 4709

e-mail: [email protected]

website : www.nicholls-colton.co.uk 0320

TEST REPORT

BS1881 CHLORIDE CONTENT

A40 Westway Viaduct

Report no. L15/2220/PBK/001

Order reference: PB86195 Date of testing: 03 to 06/11/2015

Date of receipt: 02/11/2015 Date of issue: 11/11/2015

NCA sample reference:

Client sample identification:

Client sample ref/location:

Sample type Sample depth

(mm)

Chloride Ion Content

(% by mass of concrete)


(% by mass of cement)

1 Bag 1

WW T1 D1

Concrete Dust 5-30 0.041 0.25

2 Bag 2 Concrete Dust 30-55 0.015 0.09



5 Bag 5

WW T2 D3





9 Bag 9

WW T3 B2





13 Bag 13

WW T4 B4








Tel: 0116 253 6333. Fax: 0116 251 4709



L15/2220/PBK/001





(mm)





17 Bag 17

S123 T5





21 Bag 21

S123 T6





25 Bag 25

S123 T7





29 Bag 29

S123 T8





33 Bag 33

S124 T9








Tel: 0116 253 6333. Fax: 0116 251 4709



L15/2220/PBK/001





(mm)





37 Bag 37

S125 T10





41 Bag 41

S124 T11





45 Bag 45

S124 T12





49 Bag 49

WW T13 A5





53 Bag 53

WW T14 D1





57 Bag 57

WW T15 A1/A2








Tel: 0116 253 6333. Fax: 0116 251 4709



L15/2220/PBK/001





(mm)





61 Bag 61

WW T16 C2





NOTES: 1. Testing was in accordance with BS 1881: Part 124: 1988 Clause 10.2 using potentiometric titration. 2. A cement content of 16.1% was used in the calculation of chloride ion content. 3. Samples received were smaller than required by Clause 3.2 BS 1881 : Part 124 : 1988. 4. Samples were not passed over the 150micron BS Test Sieve before testing. 5. Quality control samples are tested with each batch of samples.

......................... Parsons Brinkerhoff

The Forum Barnfield Road

Nicholls Colton Analytical Exeter EX1 1QR

RT - 1881 CaO, Page 1 of 1, Issued by LH 07.01.11 G:\Nicholls Colton Analytical\Commercial\Current Reports\2015\L15\PBK - Parsons Brinkerhoff\L15-2220-PBK\L15-2220-PBK-002.doc

N i c h o l l s C o l t o n A n a l y t i c a l


Tel: 0116 253 6333. Fax: 0116 251 4709


website : www.nicholls -colton.co.uk

0320

TEST REPORT

BS1881 CEMENT CONTENT

A40 Westway Viaduct

Report no. L15/2220/PBK/002

Order reference: PB86195 Date of testing: 03 to 06/11/2015

Date of receipt: 02/11/2015 Date of issue: 11/11/2015



Sample type Cement content by

SiO2 content (% m/m)

Cement content by CaO content

(% m/m)

Mean / Preferred Cement Content

(% m/m)

15-30640 Bag 65 Concrete Dust /

Lumps 15.9 18.9 15.9 (P)


Lumps 15.6 17.0 15.6 (P)


Lumps 16.6 17.7 17.2 (M)


Lumps 16.0 18.0 16.0 (P)


Lumps 17.0 16.4 16.7 (M)


Lumps 15.0 22.3 15.0 (P)

NOTES: 1. Testing was in accordance with BS 1881: Part 124: 1988 Clause 5 by ICP. 2. Cement content has been calculated assuming the presence in the concrete of Ordinary Portland Cement, containing 20.2% and 64.5% by mass of soluble silica and calcium oxide respectively. 3. Samples of the original constituents of the mix were not submitted. 4. Samples received were smaller than required by Clause 3.2, BS 1881: Part 124: 1988. 5. Quality control samples are tested with each batch of samples. 6. Samples were identified as being part of a batch and therefore the results are from a single analysis only.

Parsons Brinckerhoff Ltd

The Forum

Barnfield Road

Exeter

EX1 1QR

.........................

Nicholls Colton Analytical

Appendix IIIPHOTOGRAPHS

APPENDIX III – PHOTOGRAPHS1

Photograph 1 – Ladbroke Grove entrance to Westway Information Centre, at Support 121.

Photograph 2 – General view


Photograph 3 – Reinforcement exposure to support 124, west face at test area T9. Reinforcement hassurface corrosion at worse with no evidence of pitting corrosion.

Photograph 4 – Reinforcement exposure to support 125, west face at test area T15. Reinforcement hasthe initiation of pitting corrosion with approximately 10% loss of section.


Photograph 5 – Example of matting material fixed to support crosshead with a resin/adhesive. Support124, west face shown.

Photograph 6 – Leakage with associated corrosion staining to the top of the crossheads. Leakage alsoemanating behind matting. Support 123, west face shown. Test area T5 visible to crosshead.


Photograph 7 – Active leakage appears to originate behind the end of the deck beams suggesting failureof the deck joints above. Example shown is support 124, beam 9.

Photograph 8 – Section of pier cut out to facilitate the passage of services. Support 123 shown, similarsection has been cut out of support 124.


Photograph 9 – Close up of section of pier cut out to facilitate the passage of services.

Photograph 10 – Section of support 124 removed to facilitate doorway/fire exit, west face. Test area T12also visible.


Photograph 11 – Section of support 123 removed to facilitate doorway/fire exit, east face. Test area T8also visible.

Photograph 12 – A doorway (marked with red box) appears to have been cut out of support 122 andsubsequently bricked up with only a small opening remaining, presumably for services.


Photograph 13 – Small opening remaining within bricked up doorway within support 122.

Photograph 14 – Birds’ nest to top of support 124, between beams 12 & 13.


Photograph 15 – Minor compression and bulging to bearing below beam 17 of support 123, west side.

Photograph 16 – Minor compression and bulging to bearing below beam 4 of support 124, west side.


Photograph 17 – Corrosion staining and dampness to concrete bearing plinth below beam 11 of support123, west side.

Photograph 18 – Vertical cracking to concrete bearing plinth and the top of pier 122, below beam 9, eastface. Adhesive (or similar) to beam soffit around bearing – appears to be corrosion staining when viewedfrom floor level.


Photograph 19 – Vertical cracking to concrete bearing plinth and the top of pier 124, below beam 15, westface. Leachates emanating through cracking at the top of pier.

Photograph 20 – Vertical cracking to concrete bearing plinth and the top of pier 124, below beam 14, eastface. Adhesive (or similar) to beam soffit around bearing – appears to be corrosion staining when viewedfrom floor level.


Photograph 21 – Concrete bearing plinth poorly formed below beam 8 of support 122, east side.

Photograph 22 – Concrete bearing plinth poorly formed below beam 14 of support 123, east side. Overallthe bearing is supported but the corners are not contributing to load distribution.


Photograph 23 – Example of timber shuttering left in place behind bearing beam 10 of support 122, eastside. Timber appears wet, indicating leakage through deck joint.

Photograph 24 – Example of debris to top of support 122, west side.


Photograph 25 – Leakage and staining either side of beam 10, to the west of support 122 (span 72).

Photograph 26 – Leakage and water staining between beams 9 & 10, to the east of support 123 (span 74).


Photograph 27 – Close up of photograph 26. Weep pipe too short to clear beams resulting in leakage andstaining onto beam.


Photograph 28 – Leakage and staining either side of beam 11, to the west of support 124 (span 74).Fixtures and fittings fixed between beams.

Photograph 29 – Fixtures and fittings fixed between beams 16 & 17, to the east of support 122 (span 73).


Photograph 30 – Fixtures and fittings fixed between beams 15 & 16, to the east of support 122 (span 73).