25 canterbury street detailed engineering evaluation

strategy • engineering • design

25 Canterbury Street

Detailed Engineering Evaluation

Project 6179 – 01 Feb 2012

strategy • engineering • design

Contents

Introduction ...................................................................................................................... 3

Limitations of Report .......................................................................................................... 3

Executive Summary and Recommendations .......................................................................... 4

1 Statutory Regulations concerning Existing and Earthquake!prone Buildings ........................ 5

1.1 Building Act Requirements ......................................................................................... 5

1.2 Christchurch City Council (CCC) Requirements for Earthquake!Prone Buildings ................ 6

1.3 Recent Seismicity changes for Christchurch ................................................................. 6

2 Building Description ..................................................................................................... 7

2.1 General description ............................................................................................... 7

2.2 Structural System ................................................................................................. 7

3 Scope of Investigation ................................................................................................. 8

4 Building Performance in recent Canterbury Earthquakes ................................................... 9

4.1 Earthquake Damage .............................................................................................. 9

4.2 Review of Building Performance .............................................................................. 9

4.3 Critical Structural Weaknesses ................................................................................ 9

5 Seismic Assessment .................................................................................................. 10

5.1 Current state ......................................................................................................... 10

5.2 Proposed alterations ............................................................................................... 10

6 Earthquake Repairs ................................................................................................... 11

6.1 Repairs .............................................................................................................. 11

Appendix A : Christchurch City Council Compliance Schedule ................................................ 13

Appendix B : Photos of damage ......................................................................................... 14

Appendix C : Completed IEP form ...................................................................................... 17

Appendix D : Bracing Calculations ..................................................................................... 18

Appendix E : Reference Material for Repair Works ............................................................... 19

Appendix F : Sample Drawings .......................................................................................... 20

\\STX!STUDIO2!SRV\Pool\Projects\6179\E\2012!02!01 DEE.docx

of 20 strategy • engineering • design

studio2 limited

5 norwich quay po box 9

lyttelton christchurch new zealand

tel:+64 3 929 0253

[email protected] www.structex.co.nz

01 February 2012

Ian Whitehead

Christchurch City Council

53 Hereford Street

Christchurch

Email: [email protected]

Dear Ian,

Re: 25 Canterbury Street: Detailed Engineering Evaluation

Introduction

Studio2 Limited (Structex) has been engaged to complete a detailed engineering evaluation for

the building at 25 Canterbury Street, Lyttelton. This report summarises the findings of our

detailed engineering evaluation, which was undertaken in accordance with guidelines prepared by

the Post!Canterbury earthquake Engineering Advisory Group (EAG). At the time of writing this

report, these guidelines were in draft format (revision 5, released through CSG, 19th July 2011)

and under review with the Department of Building and Housing (DBH). More specifically, this

report:

(a) Highlights Building Act requirements and the Christchurch City Council policy for

earthquake!prone buildings

(b) Describes the existing building, its construction, and structural system

(c) Outlines the level of investigation undertaken and where information was obtained

(d) Summarises earthquake damage caused by the recent Canterbury earthquakes

(e) Reviews the building’s performance in the recent Canterbury earthquakes

(f) Identifies critical structural weaknesses

(g) Estimates the building’s seismic strength relative to New Building Standard (NBS),

commonly referred to as “current code”

(h) Outlines repairs to restore the building to its pre!earthquake condition

Limitations of Report

Findings presented as part of this report are for the sole use of our client, as addressed above.

The findings are not intended for use by other parties, and may not contain sufficient information

for the purposes of other parties or other uses. Our professional services are performed using a

degree of care and skill normally exercised, under similar circumstances, by reputable consultants

practicing in this field at this time. No other warranty, expressed or implied, is made as to the

professional advice presented in this report.



Executive Summary and Recommendations

The building at 25 Canterbury Street, Lyttelton, has been damaged as a result of the recent

Canterbury earthquakes. This report summarises our detailed engineering evaluation of the

building following these earthquakes. A qualitative assessment has been carried out using an

Initial Evaluation Procedure.

Overall the building performed well with damage to the building including cosmetic damage to

interior linings, cracking to unreinforced masonry infill and garden retaining walls and minor

cracking to concrete slab and masonry structural walls. Repairs options have been recommended

for the relevant damage.

Using an Initial Evaluation Procedure, the buildings seismic strength was estimated as 48.5% of

new building standard (NBS), and is therefore unlikely to be considered to be earthquake!prone

but may be a potential earthquake risk. It is recommended a quantitative engineering evaluation

is undertaken to more accurately define the buildings strength.

An option to remove an internal wall is being considered by the client. This wall is non!

loadbearing but likely contributes to the lateral load resisting system. To remove this wall the

remaining walls will need to be relined to upgrade their lateral load resisting capacity.



1 Statutory Regulations concerning Existing and Earthquake-prone Buildings

This section highlights statutory requirements concerning existing and earthquake!prone

buildings as laid out in the Building Act 2004, Building Code, and the Christchurch City Council’s

Earthquake!prone Building Policy 2010.

1.1 Building Act Requirements

The Building Act 2004 came into force on 31 March 2005 along with the Building Regulations. In

considering the structure of existing buildings the relevant sections of the Act are as follows:

Section 124 – Powers of territorial authorities in respect of dangerous, earthquake�prone, or

insanitary buildings

If the Territorial authority is satisfied that a building is dangerous or earthquake prone, the

Territorial Authority may:

(a) Put up a hoarding or fence to prevent people approaching the building;

(b) Place a notice on the building warning people not to approach the building, or

(c) Give written notice requiring work to be carried out on the building to reduce or

remove the danger.

Section 122 – Meaning of earthquake�prone building

This section of the Act deems a building earthquake prone if its ultimate strength capacity

would be exceeded, and the building would be likely to collapse causing injury or death, in a

“moderate earthquake”. The size of a “moderate earthquake” is defined in the Building

Regulations as one third the size of the earthquake used to design a new building at that

site.

Section 112 – Alterations to Existing Buildings

This section requires that after any alterations, the building shall continue to comply with

the structural provisions of the Building Code to at least the same extent as before the

alteration. This means that alteration work cannot weaken the building. Additional building

strength would therefore be required where structural elements are to be removed or

weakened, or additional mass to be added. The building will also need to be assessed in

terms of the egress from fire, and access for persons with disabilities provisions of the

Building Code and upgraded to comply, as nearly as is reasonably practicable.

Section 67� Waivers and Modifications

This section allows the Territorial Authority to grant a Building Consent subject to waivers or

modifications of the Building Code. The Territorial Authority may impose any conditions they

deem appropriate with respect to the waivers or modifications.

The Building Act was also altered by the Canterbury Earthquake (Building Act) Order 2010, which,

amongst other things, gave additional powers to the Territorial Authorities, extended the

definition of a dangerous building and extended the Schedule 1 list of building work exempt from

Building Consent.



1.2 Christchurch City Council (CCC) Requirements for Earthquake-Prone Buildings

The Christchurch City Council adopted a new policy for earthquake!prone buildings in September

2010.

The policy reflects the Christchurch City Council’s determination to reduce earthquake risk to

buildings and ensure that Christchurch “is a safe and healthy place to live in” and may be viewed

on the CCC website.

In summary, the relevant items of the policy are as follows:

(a) Buildings are assessed using the New Zealand Society of Earthquake Engineering

(NZSEE) guidelines with applied loadings from AS/NZS 1170.5 and are classed as

earthquake prone if its strength is less than 33% of the applied loading from the loading

standard AS/NZS 1170.5.

(b) It outlines the Council’s approach to earthquake!prone buildings including identification,

prioritisation, timeframes and implementation. In general, Importance Level 4 buildings

(Post!disaster facilities, as defined by AS/NZS1170) will have 15 years from 1 July 2012

to either be strengthened or demolished. Importance Level 3 (crowd or high value)

buildings will have 20 years and Importance Level 2 (normal) buildings will have 30

years. There are also additional triggers for requiring assessment and strengthening work

to be undertaken at an earlier stage (including “significant” alterations or earthquake

damage).

(c) The Council has a commitment to maintaining the intrinsic heritage values of Heritage

buildings and has some discretion with regards to strengthening levels and methods.

Each building will require discussion with Council Heritage team and Resource Consent

prior to any strengthening or repair works being undertaken.

To date the Council has identified 67% of New Building Standard (NBS), or current Code, as the

required level for strengthening of earthquake!prone buildings. However, the council may allow

strengthening to levels between 33% and 67%, on a case by case basis, taking into account the

following:

� The cost of strengthening

� Building use

� Level of danger presented by the building

� How much the building has been damaged

For buildings with a damaged building strength >33% of current code, it is recommended (but

not required) that the building also be strengthened.

1.3 Recent Seismicity changes for Christchurch

As a result of new information from the recent Canterbury earthquakes, changes have been made

to Section B1 of the Building Code, increasing seismic code levels within areas covered by the

Christchurch City, Selwyn District and Waimakariri District Councils. Such changes include:

� Increasing the zone hazard factor (Z) in AS/NZS1170.5 from 0.22 to 0.3, and

serviceability limit state risk factor (Rs) from 1.25 to 1.33.

� Replacing Section 5 of NZS3604:1999 with NZS3604:2011 Section 5, adopting Earthquake

Zone 2.

These changes came into effect on the 19th May 2011 and are interim code levels pending further

seismological study and investigation. For further information on other changes refer:

http://www.dbh.govt.nz/information!sheet!seismicity!changes.



2 Building Description

2.1 General description

Building name: !

Address: 25 Canterbury Street, Lyttelton

Building use: Offices to first floor, carparking/storage to ground floor

Heritage category: !

Number of storeys: 2

Roof construction Tiles on timber truss

Wall construction: Timber framing to upper storey, concrete masonry to lower storey.

Floor construction: Precast “unispan” with concrete topping to first floor, concrete slab on

grade ground floor

Subfloor construction: Shallow concrete foundations

Year built: 1976!1977

Approx. floor area: 115 m2

Building Importance: 2 (NZS1170.0)

2.2 Structural System

Timber roof trusses span front to back onto timber framed walls. Suspended floor construction is

pre!stressed precast concrete “unispan” spanning on to concrete masonry ground floor walls and

precast concrete lintel to front elevation. The building is founded on shallow concrete strip

footing. In two locations shallow concrete piles and foundation beams are used to bridge a brick

culvert.

The building is clad with tiles to the roof and brick veneer to three sides of the upper storey. The

South elevation of the upper storey is clad with lightweight board. The lower storey walls are left

as exposed masonry. The Northern and Eastern masonry walls act as a partial height retaining

wall. The interior to the upper storey is clad with plaster board and the interior to the lower

storey is left as exposed masonry. One garage door has been infilled with unreinforced concrete

masonry. A timber framed, plywood lined wall has also been constructed to subdivide the lower

storey.

Lateral load resisting system is via plaster board linings to upper storey walls. Load then

distributed through first floor diaphragm to ground floor masonry walls.



3 Scope of Investigation

Our detailed engineering evaluation has been undertaken in accordance with Engineering

Advisory Group (EAG) guidelines “Guidance on Detailed Engineering Evaluation of Earthquake

Affected Non!residential Buildings in Canterbury”. At the time of writing this report, these

guidelines were in draft format (revision 5, released through CSG, 19th July 2011) and under

review with the Department of Building and Housing (DBH).

Our building evaluation and assessment has been based on the following information:

(a) A visual inspection of the building carried out on the 30!01!2012, which included:

� The exterior from ground level

� The interior

(b) Limited structural and architectural drawings obtained from the council property file

The following non!structural aspects fall outside the scope of this report and have not been

covered by this investigation and assessment:

� Compliance items covered by the building Warrant of Fitness (A list of such items has been

included in Appendix A)

� An electrical safety review

� A fire safety review

These items should be inspected and assessed by qualified trades people or specialists prior to

the building being reoccupied or repair/strengthening works carried out. We request such persons

be instructed to identify loose and/or inadequate fixings, and to notify the engineers if these are

found.



4 Building Performance in recent Canterbury Earthquakes

4.1 Earthquake Damage

Generally the building has suffered minor damage as a result of the recent Canterbury

earthquakes; this damage observed is briefly described below. Photos are included in Appendix B

to indicate the nature of the observed damage. These are not meticulous or comprehensive

records of all damage but have been included to provide an indication of the damage.

� Cracking of interior linings to first storey

� Broken/cracked floor tiles in bathroom

� Slight subsidence to Southwest corner visible on first floor

� Vertical cracks to Northern and Eastern masonry walls to ground floor

� Small areas of spalled concrete to Northern and Eastern masonry walls to ground floor

� Cracking and movement of garden retaining wall

� Cracking to ground floor slab around rear columns

� Areas of cracked asphalt around site

� Cracking and movement of unreinforced masonry infill to Eastern garage door

4.2 Review of Building Performance

Generally the building has performed well during the recent Canterbury earthquakes. To the

upper storey no damage was observed to the roof cladding or the exterior brick veneer while

damage to the interior is largely of a cosmetic nature.

Damage to the ground floor is minor, with the cracking to the slab likely associated with

settlement of the foundations relative to the slab, especially as the slab does not appear to be

tied to the foundations. Areas of unreinforced masonry such as garage door infill and garden

retaining wall have performed poorly as expected having low strength and being poorly tied to

the main building.

4.3 Critical Structural Weaknesses

From a review of existing drawings and visual inspections of the building, no critical structural

weaknesses were identified.



5 Seismic Assessment

5.1 Current state

A seismic assessment of the building has been carried out using the Initial Evaluation Procedure

(IEP) from the New Zealand Society for Earthquake Engineering (NZSEE) “Assessment and

Improvement of the Structural Performance of Buildings in Earthquakes” guidelines (June 2006).

This procedure provides an estimate of building seismic strength, relative to New Building

Standard (NBS), based upon the buildings age, type of construction, and any known structural

deficiencies. This procedure does not constitute a quantitative assessment, and should be used

primarily for the purposes of assessing whether a further quantitative assessment is required. A

copy of the IEP form has been included in Appendix C.

Using the Initial Evaluation Procedure the current strength of this building is estimated to be

48.5% of NBS. While this suggests the building is not earthquake prone it may still pose a

potential risk and it is recommended a quantitative DEE is carried out to give a more accurate

assessment of the buildings strength.

5.2 Proposed alterations

The client wishes to investigate removing an interior wall to suit the intended building use.

Proposed wall is that between the conference room and the adjacent office. The roof trusses span

parallel to this wall so it is not loadbearing but may be required for bracing purposes.

Bracing requirements are checked using demands from NZS 3604:2011 for a single storey house

with heavy roof and heavy walls. The capacity of the interior walls was calculated in accordance

with New Zealand Society for Earthquake Engineering (NZSEE) “Assessment and Improvement of

the Structural Performance of Buildings in Earthquakes” guidelines (June 2006).

This assessment found that the seismic demand on the upper storey is 86kN in each direction.

The current capacity across the building is assessed as 65kN, below the assessed demand and

reflects the estimated strength found using the IEP. Calculations for this assessment are included

in Appendix D.

If the internal wall is to be removed, an additional 38kN of bracing will need to be provided to the

remaining walls. This is likely to involve relining all remaining walls with GIB Braceline and

improving the timber framing fixings to the first floor slab to suit the GIB requirements. Full

specifications for this work can be provided should these alterations proceed.



6 Earthquake Repairs

This section describes repair works to restore the building to its pre!earthquake condition. In

some cases, further investigation of existing construction will be required. Where appropriate, this

has been noted.

6.1 Repairs

This section describes options of repair to restore the building to its pre!earthquake condition.

These repairs are subject to change as the works proceed and as further information regarding

existing construction and the extent of damage is revealed. On!site correspondence with the

contractor carrying out the works may be required.

Where appropriate several options for repair have been provided. The most appropriate option

will depend on the specific nature of the damage exposed on a case!by!case basis. In some

cases, the repair option chosen will require discussion with the owner and their insurer.

The costs associated with the repairs will require assessment by a quantity surveyor and/or

qualified contractor who will need to visit the site to view the extent of damage and work

required.

Repairs to garden retaining wall:

� Deconstruct displaced concrete masonry retaining wall adjacent to the dwelling and

reinstate to current building standards.

Repairs to concrete masonry infill:

� Remove unreinforced masonry infill and replace with timber framing or reinstate garage

door to suit owners requirements.

Foundation re�levelling and repairs:

� Survey floor to determine slopes and levels.

� Refer Table 4.1 in 0 to determine whether: (a) no action is necessary; (b) a foundation re!

level is required; or (c) a foundation rebuild is required. Note that the Department of

Building and Housing is in the process of revising this table, and floor slope criteria are

likely to become less stringent.

� If a foundation re!level is required, re!level foundations as per repair method statements

in 0.

� As an alternative to jacking concrete foundation walls, the floor above can be propped and

the existing foundation walls removed and reconstructed in reinforced concrete masonry

with new strip footings to the required floor level.

� Jacking and/or re!levelling floors may inadvertently cause cracking to wall linings due to

differential movement. Allowance should be made to repair such damage after the re!

levelling is complete.

Repair to concrete slab�on�grade:

� Grind out and seal cracks using Sikaflex 11FC(A).

� Alternatively, seal using a pressure!injected epoxy such as Sikdur Injectokit TH(A).

Repair to spalled concrete:

� Break!out loose concrete.

� If reinforcement is exposed, allow engineer to inspect condition of reinforcement. Repairs

may be required.

� For corroded reinforcement, wire brush off loose material and spray with a rust convertor.

� Patch repair spalled areas using Sika MonoTop Structural Mortar and Primer in accordance

with Sika specifications(A). For smaller patch repairs, use Sikadur 41 with Sikadur 32

tie coat.



Repair to cracked masonry blockwork:

� Rake!out cracked mortar and re!grout/re!point.

� Alternatively, seal cracks larger than 0.2mm using a pressure injected epoxy(A). If the

masonry is not solid filled, Sikadur Injectokit TH is likely to be appropriate. If solid filled,

Sikadur Injectokit LV or Sikadur 52 is likely to be appropriate.

� Reinstate paint finish to match existing.

Repair to damaged internal wall and ceiling linings:

� Repair and/or replace damaged GIB wall and ceiling linings in accordance with GIB

recommendations. Refer www.gib.co.nz/earthquakebulletin ! this document outlines

appropriate repairs depending on the specific type of damage encountered.

� For minor isolated cracks to plaster linings (smaller than 300mm in any direction), grind!

out V!shaped groove along crack. Re!plaster over groove, utilising fibreglass mesh

reinforcement across the crack.

� For larger cracks/fractures to plaster linings, remove and replace with GIB in accordance

with GIB literature.

� Replace water damaged ceilings with GIB linings in accordance with GIB literature.

� Sand, prime and repaint over to match existing.

Other non�structural repairs:

� Ease and adjust any jammed/catching doors/windows/etc.

� Realign and re!fix any dislodged timber architraves, frames, skirting boards and trims.

� Sand, prime and repaint over to match existing.

� Repair/replace broken windows and frames as required.

(A) Refer attached SIKA specification to confirm most suitable product for specific application and

for information on product installation. For further information, contact SIKA.

If you have any queries regarding the above Structural Assessment Report, please do not

hesitate to contact the undersigned.

Yours sincerely, Reviewed by,

Studio2 Ltd Studio2 Ltd

Adam Walker Will Lomax

B.E.(Hons), M.E., GIPENZ B.Eng(Hons), CPEng#226903, IntPE

Structural Engineer Director

Studio2 Limited Studio2 Limited



Appendix A: Christchurch City Council Compliance Schedule



Appendix B: Photos of damage

Damage to interior linings






Damage to bathroom floor linings


Cracking to asphalt pavement

Damage to masonry infill

Cracking to garden retaining wall

Crack to masonry infill



Cracking to ground floor slab

Spalled concrete to base of masonry walls

Vertical crack to masonry walls Vertical crack to masonry walls



Appendix C: Completed IEP form


Page 18 of 20 strategy • engineering • design

Appendix D: Bracing Calculations



Appendix E: Reference Material for Repair Works

16 REVISED GUIDANCE ON REPAIRING AND REBUILDING HOUSES AFFECTED BY THE CANTERBURY EARTHQUAKE SEQUENCE

PART A : SECTION 2 : FOUNDATION ASSESSMENT CRITERIA AND APPROACHES

Table 2.3: Indicator criteria for floor/foundation re-level or rebuild

COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5

Floor type NO foundation

re-level considered

necessary

Foundation re-level

indicated

Foundation rebuild

indicated

House rebuild may

be indicated

Type A

Timber framed

suspended timber floor

structures supported

only on piles

The slope of the floor

between any two

points >2 m apart is

<0.5% (1 in 200)

[Note a]

and

The variation in level

over the floor plan is

<50 mm

The variation in floor

level is >50 mm and

<100 mm

Note that the floor

re-level is expected to

be achieved by packing

the piles

The variation in floor level

is >100 mm [Note c]

over the floor plan

or

The floor has stretched

>50 mm [Note d]

Note that full or partial

re-piling is expected

to be undertaken to

achieve a level floor

The house has fully or

partially collapsed off

the piles and repair may

be uneconomic

This will relate

to the degree of

superstructure damage

[Note f]

Type B

Timber framed

suspended timber

floor structures with

perimeter concrete

foundation


between any two


<0.5% (1 in 200)

[Note a]

and



<50 mm


level is >50 mm and

<100 mm [Note b]

The variation in floor level

is >100 mm [Note c] over

the floor plan

or

Individual cracks in the

perimeter foundation

are >5 mm,

or

The floor has stretched

>20 mm [Note e]

The house has fully or

partially collapsed off

the piles and repair may

be uneconomic

This will relate

to the degree of


[Note f]

Type C

Timber framed dwelling

on concrete floor


between any two


<0.5% (1 in 200)

[Note a]

and

The variation in level over

the floor plan is <50 mm

and

There are no cracks in

ceramic floor tiles

and

There is no distress in

vinyl floor coverings

or carpet


level is >50 mm and

<150 mm

and

Services are

functioning



>150 mm

or

There is irreparable

damage to buried

services within the

house footprint

This will relate

to the degree of


[Note f]

Standard Specifications

for

Repair of cracks in concrete structures

and

Repair of spalled concrete

PROJECT NAME:

PROJECT LOCATION:

SCOPE OF WORK:

SPECIFICATION DATE: SPECIFICATION No.:

Contents

1. Flow chart for post-earthquake repair of cracks in concrete structures 2. Flow chart for post-earthquake repair of spalled concrete 3. Specification for Crack Injection using Sikadur Injectokit-LV 4. Specification for Crack Injection using Sikadur Injectokit-TH 5. Specification for Crack Injection using Sikadur 52 6. Specification for Concrete Repair using Sika MonoTop Structural Mortar 7. Specification for Concrete Repair using Sika MonoTop High Build Mortar 8. Specification for Concrete Repair using Sika MonoTop Micro Concrete 9. Specification for Sprayed Concrete Repair 10. Specification for Concrete Repair using Sika FastFix-125 (with MonoTop Primer) 11. List of Sika Approved Contractors for Concrete Repair and Protection Systems

Crack is dry or slightly damp

Structural repair required

Non-structural repair required

Water flowing from crack under hydrostatic pressure

Wet crack

Have access to both sides of crack

Only have access to one side of crack

0.2 – 5mm wide

0.2 – 2mm wide

>2mm wide

Sikadur Injectokit LV (2) Sikadur 52 (2)

Sikadur Injectokit TH (2)

Sikadur 52 (2) + Extender T Sikadur 31 (2)

Crack is wet or there is flowing water

Crack injection

Surface sealing of rear of wall by curtain injection

Sika Injection-101 + Sika Injection-201

Sika Injection-304

Sika Injection-201

Post-earthquake repair of cracks in concrete structures

Repair to be painted

Injection as per structural repair option above (2)

Repair not painted

Grind out crack and fill with Sikaflex 11FC

Grind out crack and fill with Sikadur 51 (2)

Floor cracks >10mm wide: Grind out / fill with Sikadur 31 (2)

Notes: 1. This information is provided to assist in choosing the best-suited product for different crack repair situations. It is provided as a guide only. It is, by

its nature, very general, and cannot cover all situations. All repair products shall be chosen based on a thorough understanding of the structural requirements and installed in accordance with the information provided on the relevant Product Data Sheets. For assistance please contact your local Sika Technical Representative.

2. The repairs products marked (2) are rigid and should only be used in stable, non-moving cracks.

Version 1: 27/09/2010

SPECIFICATION FOR CRACK INJECTION USING SIKADUR INJECTOKIT-LV PRODUCTS: 5 Minute Epoxy (The current data sheet is dated 02/08)

Sikadur UA (The current data sheet is dated 02/08) Sikadur Injectokit-LV (The current data sheet is dated 08/09)

1 General 1.1 This technical specification is to be read in conjunction with the project Contract

Documents and Specification. 1.2 All work to be carried out in accordance with the current Sika (NZ) Ltd data sheets. 2 Surface preparation 2.1 All concrete surfaces must be clean and free from any loosely adhering particles, or

contaminants such as dirt, oil, dust, grease, etc. 2.2 The cracks must be blown out with oil-free, dry compressed air. 3 Application of the surface sealant 3.1 5 Minute Epoxy or Sikadur UA CONCRETE FIX can be used as the surface sealant,

depending on the waiting period between application of the surface sealant and injection.

3.2 Immediately after mixing, apply a small amount of compound to the back of each nipple making sure that the valve will not be blocked, and place the nipple over the crack. (Ensure that the valve is centred over the crack.)

3.3 Nipples should be placed between 200 mm and 500 mm apart dependent on crack size. 3.4 Additional sealant should be applied onto the flange of the nipple to ensure a resin tight

seal to the substrate. 3.5 Surface sealant should be knifed into the crack between nipples to ensure a resin tight

seal. 3.6 Continue the sealant 50 mm beyond the end of the line of the visible crack. 3.7 Application of the injection system may be commenced as soon as the surface sealant

has fully hardened. 4 Injection of the Sikadur Injectokit-LV epoxy resin 4.1 Hit the side of the capsule near the base with a hammer 2 or 3 times on different sides to

break the internal glass container of hardener. (The glass can be heard moving when broken.)

4.2 To mix the resin, invert the cartridge 20-30 times slowly. Do not shake vigorously otherwise air will be incorporated.

4.3 Use the mixed material within the usable life. 4.4 Pierce the foil seal in the threaded end of the cartridge. 4.5 Screw the Sikadur Injectokit-LV hose onto the cartridge. 4.6 Ensure that the rubber ‘O’ ring is in place on the cartridge.

Specification

4.7 Do not over tighten the fitting as this may distort the ‘O’ ring. 4.8 Place the cartridge into a standard sealant gun. 4.9 Push the free end of the Sikadur Injectokit-LV hose onto the first (lowest) nipple and

tighten down the locking cap. Do not over tighten. 4.10 Insert an air release pin into the next nipple above the injection point. (Do not start

pumping until the air release pin is inserted to open the non return valve and release trapped air.)

4.11 Commence pumping slowly, do not use excessive pressure. 4.12 When resin appears at the nipple next to the injection point: (a) stop pumping (b) release the pressure on the injection gun (c) remove the air release pin (d) unscrew the cap and with a twisting movement pull off the Sikadur Injectokit-LV hose. 4.13 Attach the Sikadur Injectokit-LV hose to the next nipple. 4.14 Insert air release pin in nipple beyond and recommence pumping. 4.15 Repeat the process until the entire length of crack has been injected. 4.16 On completion of pumping, the last cartridge can be left connected and pressurised

slightly to allow for possible seepage into deep seated cracks. 5 Making good 5.1 After the Sikadur Injectokit-LV injection resin has set, remove the nipples. These can be

knocked off with a hammer. 5.2 Make good any holes or voids with the selected surface sealant. 5.3 The existing surface sealant can then be removed by either grinding or heating with a

hot air gun and scraping the surface until the original substrate profile is restored. 6 Cleaning 6.1 Tools and application equipment should be cleaned using Sika Colma Cleaner. Note: This outline procedure details the key components of the work required. For specific details

regarding surface preparation, mixing of the products and application, refer to the product data sheet.

Specification

SPECIFICATION FOR CRACK INJECTION USING SIKADUR INJECTOKIT-TH PRODUCTS: 5 Minute Epoxy (The current data sheet is dated 02/08)

Sikadur UA (The current data sheet is dated 02/08) Sikadur Injectokit-TH (The current data sheet is dated 08/09)

1 General 1.1 This technical specification is to be read in conjunction with the project Contract

Documents and Specification. 1.2 All work to be carried out in accordance with the current Sika (NZ) Ltd data sheets. 2 Surface preparation 2.1 All concrete surfaces must be clean and free from any loosely adhering particles, or

contaminants such as dirt, oil, dust, grease, etc. 2.2 The cracks must be blown out with oil-free, dry compressed air. 3 Application of the surface sealant 3.1 5 Minute Epoxy or Sikadur UA CONCRETE FIX can be used as the surface sealant,

depending on the waiting period between application of the surface sealant and injection.

3.2 Immediately after mixing, apply a small amount of compound to the back of each nipple making sure that the valve will not be blocked, and place the nipple over the crack. (Ensure that the valve is centred over the crack.)

3.3 Nipples should be placed between 200 mm and 500 mm apart dependent on crack size. (Where cracks can be sealed on one side only, nipples should be placed at centres which are 80% of the depth to which the resin is required to penetrate.)

3.4 Additional sealant should be applied onto the flange of the nipple to ensure a resin tight seal to the substrate.

3.5 Surface sealant should be knifed into the crack between nipples to ensure a resin tight seal.

3.6 Continue the sealant 50 mm beyond the end of the line of the visible crack. 3.7 Application of the injection system may be commenced as soon as the surface sealant

has fully hardened.

Specification

4 Injection of the Sikadur Injectokit-TH epoxy resin 4.1 Cut the top off the conical nozzle. 4.2 Insert T-shaped rod and turn clockwise to engage stirring head in cartridge. 4.3 Push rod down the full length of the cartridge to break the membrane separating the

resin and hardener. 4.4 Pump up and down 30 to 40 times to mix resin and hardener. 4.5 Turn the T-shaped rod anticlockwise to disengage and then remove. 4.6 Do not shake. 4.7 Unscrew the conical nozzle and discard. 4.8 Use the mixed material within the usable life. 4.9 Screw the Sikadur Injectokit-TH hose onto the cartridge. 4.10 Ensure that the rubber ‘O’ ring is in place on the cartridge. 4.11 Do not over tighten the fitting as this may distort the ‘O’ ring. 4.12 Place the cartridge into a standard sealant gun. 4.13 Push the free end of the Sikadur Injectokit-TH hose onto the nipple positioned over the

widest point of the crack and tighten down the locking cap. Do not over tighten. 4.14 Insert an air release pin into the nipple adjacent to the injection point. (Do not start

pumping until the air release pin is inserted to open the non return valve and release trapped air.)

4.15 Commence pumping slowly, do not use excessive pressure. 4.16 When resin appears at the nipple next to the injection point: (a) stop pumping (b) release the pressure on the injection gun (c) remove the air release pin (d) unscrew the cap and with a twisting movement pull off the Sikadur Injectokit-TH

hose. 4.17 Attach the Sikadur Injectokit-TH hose to the next nipple. 4.18 Insert air release pin in nipple beyond and recommence pumping. 4.19 Repeat the process until the entire length of crack has been injected. 4.20 On completion of pumping, the last cartridge can be left connected and pressurised

slightly to allow for possible seepage into deep seated cracks. 5 Making good 5.1 After the Sikadur Injectokit-TH injection resin has set, remove the nipples. These can be

knocked off with a hammer. 5.2 Make good any holes or voids with the selected surface sealant. 5.3 The existing surface sealant can then be removed by either grinding or heating with a

hot air gun and scraping the surface until the original substrate profile is restored. 6 Cleaning 6.1 Tools and application equipment should be cleaned using Sika Colma Cleaner. Note: This outline procedure details the key components of the work required. For specific details


Specification

SPECIFICATION FOR CRACK INJECTION USING SIKADUR 52 PRODUCTS: Sikadur 31 (The current data sheet is dated 05/04)

Sikadur 52 (The current data sheet is dated 07/01) 1 General 1.1 This technical specification is to be read in conjunction with the project Contract

Documents and Specification. 1.2 All work to be carried out in accordance with the current Sika (NZ) Ltd data sheets. 2 Outline Procedure 2.1 Crack widths between 0.2mm and 5mm may be successfully injected. 2.2 All concrete surfaces must be clean and free from any loosely adhering particles, or

contaminants such as dirt, oil, dust, grease, etc. 2.3 The cracks must be blown out with oil-free, dry compressed air. 2.4 Use Sikadur 31 to seal off the crack and fix the Sika Injection Flanges over the cleaned

and prepared cracks at 300mm to 500mm intervals. 2.5 Inject epoxy into the cracks in accordance with the procedure on the Sikadur 52 data

sheet. Note: This outline procedure details the key components of the work required. For specific details


Specification

Sika Approved Contractors Concrete Repair and Protection Systems

Christchurch Based (Alphabetical order only)

Adhesion Sealing Ltd Ph 03 365-0914 Fax 03 365-2314 Contact Justin Ashwell Mob 027 503-4441 Email [email protected] Application Specialists Ltd Ph 03 384-3200 Fax 03 384-3200 Contact Sam Webster Mob 022 042-8870 email [email protected] Concrete Protection & Repair Ltd Ph 03 349-0334 Fax 03 349-0335 Contact Graeme Smith Mob 021 337-095 Email [email protected] Construction Techniques Ltd Ph 03 339-0426 Fax 03 339-0526 Contact Peter Higgins Mob 021 332-620 Email [email protected] Fulton Hogan Civil South Ltd Ph 03 375-9060 Fax 03 323-7346 Contact Phil Wilby Mob 027 222-5654 Email [email protected] Goleman & Co Ltd Ph 03 982-3830 Fax 03 982-3832 Contact Luke Goleman Mob 021 242-5000 Email [email protected] Waterproofing Concepts Ltd Ph Fax Contact James Kirkpatrick Mob 021 197-7196 Email [email protected]



Appendix F: Sample Drawings