Specification - Tunnel Shotcrete Lining

8/10/2019 Specification - Tunnel Shotcrete Lining

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Cv

Thiess John HollandJoint Venture

Ai rport Link | NorthernBusway | EWAG

GL - Supplementary

Specification - Tunnel -Shotcrete LiningGLTSP102

Document refBC-PBA-GLTSP102-SPC-0001-1-0326 May 2010

DCN: 00047IFA / AFC


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Thiess John HollandJoint Venture

Ai rport Link | NorthernBusway | EWAG

GL - Supplementary

Specification - Tunnel -Shotcrete LiningGLTSP102

May 2010


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Document Verification

Page 1 of 1

Job title Airport Link | Northern Busway | EWAG Job number

PB2108209A A125840

Document title GL - Supplementary Specification - Tunnel - Shotcrete LiningGLTSP102

File reference

Document ref BC-PBA-GLTSP102-SPC-0001-1-03 26 May 2010

Revision Date Filename BC-PBA-AGTSP100-SPC-0002-0-01.doc

AFC Issue 25/02/09 Description AFC Issue

Prepared by Checked by Approved by

Name Andreas Amon Robert Bertuzzi Eddie Woods

Signature

Review 16/02/10 Filename BC-PBA-GLTSP102-SPC-0001-1-01.doc

Description Issued for Review, DCN: 00047, Refer to Table 2


Name Eddie Woods Richard Page Eddie Woods

Signature

Review 29/03/10 Filename BC-PBA-GLTSP102-SPC-0001-1-02.doc

Description Issued for External Review, DCN: 00047, Refer to Table 2


Name Eddie Woods Richard Page Eddie Woods

Signature

IFA / AFC 26/05/10 Filename BC-PBA-GLTSP102-SPC-0001-1-03.doc

f C C f


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Thiess John Holland Joint Venture Airport Link | Northern Busway | EWAGGL - Supplementary Specification - Tunnel - Shotcrete Lining GLTSP102

Contents

Page

1 General 1

1.1

Scope 1

1.2

Definition of Terms 2

1.3 Standards and Related Specifications 3

1.4

Discrepancy Between Drawings and Specification 5

1.5

Changes to previous revisions 5

1.6 Records Maintained by the Contractor 8

2

Quality System Requirements 9

2.1 General 9

2.2 Hold Points, Witness Points and Milestones 9

2.3

Work Method Statements 10

2.4 Testing Frequency 10

2.5

QDMR Registered Suppliers and Products 10

3 Shotcrete Materials 11

3.1 General 11

3.2

Shotcrete Types 11

3.3

Water 11

3.4 Cement 11

3.5

Supplementary Cementitious Materials 12

3.6 Aggregates 12

3.7

Alkali-Aggregate Reaction (AAR) 14

3.8

Admixtures 14

3.9 Fibres 16

3.10

Soluble Salts (permanent shotcrete only) 17

4

Shotcrete Requirements 17

4 1 Constr ction Method Statements 17


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6.1

Equipment 24

6.2

Proficiency of Nozzlemen 25

6.3

Production and Transport 25

6.4

Application 26

6.5

Thickness and Profile Control 27

6.6

Curing 28

7 Shotcrete Testing 28

7.1

Production Tests 28

7.2

Compressive Strength Test 30

7.3 Flexural Toughness Test 31

7.4

Dry Density, Boiled Absorption and Voids Volume 31

7.5

Fibre Content 31

7.6 Slump 32

7.7

Test of Steel Fibre 32

8 Repair of Shotcrete 32

8.1 General 32

8.2

Core Hole Repair 32

9 Remedial Works to Non-Conforming Shotcrete 32

9.1

General 32

9.2

Compressive Strength Failures 33

Tables

Table 1 Definition of Terms

Table 2 Changes made to previously issued revisions

Table 3 Hold Points

Table 4 Witness Points

Table 5 Milestones

Table 6 Work Method Statements

Table 7 Items Requiring Use of QDMR Registered Suppliers and Products

Table 8 Aggregate Grading for Shotcrete

Table 9 Maximum Dosages of Accelerator


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1 General

This technical specification has been provided by Parsons Brinckerhoff Arup Joint Venture

on behalf of Thiess John Holland Joint Venture for use in execution of the Design andConstruct Contract with the Airport Link, Northern Busway and ARU project (the Project).

1.1 Scope

This specification supersedes Shotcrete Lining (reference AGTSP100-0002).

This Specification applies to the manufacture, supply and application of shotcrete for the

temporary and permanent (pump sumps and substations) shotcrete lining of the Airport Link

and Northern Busway tunnels. In addition, this document specifies the performance basedrequirements for shotcrete and details the testing requirements to ensure that the shotcrete

applied on site is consistent with these performance requirements.

For this Project, shotcrete is concrete with or without admixtures pneumatically applied to a

prepared rock surface, in and around steel sets, or in and around lattice girders.

The scope of this Specification comprises:

steel or synthetic fibre reinforced shotcrete (SFRS),

steel mesh reinforced shotcrete

and plain or unreinforced shotcrete (URS)

plain shotcrete with polypropylene fibres to provide fire protection

aggregates for use in permanent shotcrete requiring fire resistance

The specification covers both temporary works shotcrete and permanent shotcrete. The

specification complies with the Mined Tunnels Design Manual and will be reviewed andupdated as necessary during execution of the Works.

The types of shotcrete for underground works are as follows:

SFRS applied as temporary (initial) and permanent (pump sumps and substations)

ground support

URS applied as a smoothing layer prior to installation of the tunnel waterproofing

membrane or providing an initial layer in combination with mesh reinforcement prior to

application of permanent lining or as a finishing layer for permanent ground support

(pump sumps and substations).

This Specification shall be read in conjunction with the Temporary and Permanent Works

Design Drawings and other relevant Specifications. The thickness dimensions shown on the

Drawings are minimum thicknesses. Shotcrete thicknesses shall be such as to provide a


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1.2 Definition of Terms

Definitions applicable to many specifications, including this Specification, shall include those

found in the General Specification (reference BC-PBA-GLRSP000-SPC-0001).

While the definitions found in the General Specification take precedence, the following

definitions, when not found in the General Specification, apply particularly to this

Specification:

Table 1 Defin ition of Terms

Term Definition

Relative Strength forSilica Fume

The relative strength for silica fume is the ratio (in percent) of thecompressive strength of standard mortar bars, prepared with 90% cement

plus 10% silica fume by mass, to the compressive strength of standard

mortar bars made from cement only.

Admixtures Materials added to base concrete such as accelerators and hydration

control mixtures. (Note that silica fume, plasticisers and retarders may be

included in Base Concrete if proposed to be used in the Temporary and

Permanent Works shotcrete).

Cement An active hydraulic binder formed by grinding clinker and conforming to AS

3972. Cement and cementitious content exclude the mass of silica fume.

Characteristic

Cylinder strength at

28 days

The value of the standard cylinder strength at 28 days below which 5% of

the population of all possible strength measurements are expected to fall.

(Characteristic cylinder strengths are quoted in the Specification for the

purpose of the development of mix design only).

Curing The control of temperature and moisture in the concrete until the concretehas developed required properties.

Flash Coat Sprayed concrete applied as a thin layer protecting, priming or finishing the

surface of the tunnel. A flash coat shall be at least 20mm thick.

In Situ Cylinder

Strength

The notional strength of shotcrete at a single location, considered as the

strength of a cylinder of shotcrete as it exists in the structure. In situ cylinder

strengths are given in the Specification for the purpose of compliance

requirements.

Lattice Girder A lightweight, three dimensional steel or fibreglass frame made to act as a

unit by connecting all components with lacing bars; used in conjunction with

shotcrete for shotcrete lining reinforcement.

Layer A discrete thickness of sprayed concrete built up from a number of passes


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Term Definition

nozzle into place to produce a dense, homogeneous mass, applied directly

to the ground surface in one or more layers to form the lining of a sprayedconcrete support structure.

Shotcrete Type S1 Steel fibre reinforced shotcrete (SFRS) which is applied as initial or primary

ground support and is designed to carry temporary loads only.

Shotcrete Type S2 Steel mesh reinforced shotcrete (SMRS) which is applied as initial or

primary ground support and is designed to carry temporary loads only.

Shotcrete Type S3 Un-reinforced shotcrete (URS) which is applied as initial or primary ground

support and is designed to carry temporary loads only.

Shotcrete Type S4 Un-reinforced shotcrete (URS) which is applied as backfill shotcrete,

smoothing shotcrete and/or as a protective layer to shotcrete Type S1, P1

or bare rock, and is designed to carry temporary loads only.

Shotcrete Type P1 SFRS which is applied as permanent ground support and is designed to

carry permanent loads.

Shotcrete Type P2 SMRS which is applied as permanent ground support and is designed tocarry permanent loads.

Shotcrete Type P3 Plane shotcrete used as a smoothing layer and to provide fire protection

Shotcrete Mix Terms Base Mix: Concrete designed, tested and supplied independent from the

shotcreting process, equipment and personnel.

Shotcrete Mix: The base mix after it is applied to the Works, or to test

panels.

Sprayed Concrete

Support Systems

Structure

A structure built underground in accordance with this specification.

Standard Cylinder

strength

The measured compressive strength of a cylinder made, cured and tested

in accordance with AS 1012.8 and AS 1012.9 for cast samples and in

accordance with AS 1012.14 for cored samples.

URS Unreinforced Shotcrete

Waterproofing

Supervisor

As defined in the Waterproofing and Drainage Specification (reference BC-

PBA-GLTSP107 SPC-0001).

Wet-mix Process The process of producing shotcrete in which cement and aggregate are

weigh batched and mixed with water at or near the shotcreting location or in

mixer trucks prior to being pumped through a pipeline to a nozzle where


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BC-PBA-GLTSP101-SPC-0001 Global Supplementary Specification Tunnel - Rock

Reinforcement

BC-PBA-GLTSP102-SPC-0001 Global Supplementary Specification Tunnel - MinedTunnel Excavation and Implementation

BC-PBA-GLTSP106-SPC-0001 Global Supplementary Specification Tunnel Cast in

Place Concrete

BC-PBA-GLRSP009-SPC-0001 Global Supplementary Specification Road Projectwide

Instrumentation and Monitoring

BC-PBA-GLTSP107-SPC-0001. Global - Supplementary Specification Waterproofing and

Drainage

BC-PBA-AGDTR100-RPT-0001 Durability Technical Report

PSTS

PSTS01 Introduction to Technical Standards

PSTS03 Drainage, Retaining Structures and Protective Treatments

PSTS50 Specific Quality System Requirements

PSTS70 Concrete

PSTS71 Reinforcing Steel

Austral ian Standards

AS 1012 Methods of Testing Concrete

AS 1141 Methods for Sampling and Testing Aggregates

AS 1379 Specification and Supply of Concrete

AS 1478.1 Chemical Admixtures for Concrete

AS 2350 Methods of Testing Portland and Blended Cements

AS 2758.1 Aggregates and Rock for Engineering Purposes Concrete Aggregates

AS 3582.1 Supplementary cementitious materials for use with Portland and blended

cement Fly Ash


cement Slag Ground Granulated Iron Blast Furnace


cement Silica Fume

AS 3583 6 Methods of test for supplementary cementitious materials for use with


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ASTM C311 Standard Test Methods for Sampling and Testing Fly Ash or Natural

Pozzolans for Use in Portland-Cement Concrete

ASTM C94 Standard Specification for Ready-Mixed Concrete

British Standards

BS EN 1367-2 Tests for Thermal and Weathering Properties of Aggregates

BS EN 14488-4 Testing sprayed concrete. Bond strength of cores by direct tension

BS EN 14488-7 Testing sprayed concrete. Fibre content of fibre reinforced concrete

BS EN 14889-1 Fibres for concrete - Part 1: Steel fibres - Definitions, specification and

conformity

BS EN 14889-2 Fibres for concrete - Part 2: Polymer fibres - Definitions, specification and

conformity

Other Standards

ACI 506R-05 Guide to Shotcrete

Specification for Tunnelling, British Tunnelling Society and the Institution of Civil Engineers

ITA-shotcrete guidelines, Sprayed concrete for final linings: ITA working group report,

AITES / ITA, 2001

Concrete Institute of Australia, Recommended Practice Shotcreting in Australia

1.4 Discrepancy Between Drawings and Specification

Where a discrepancy exists between the Design Drawings and this Specification the

Contractor shall seek clarification from the Construction Certifier. Drawing notes will takeprecedence over the Specification.

1.5 Changes to previous revisions

The following table details all the changes made to this specification since previously issued

revisions.

Table 2 Changes made to previously issued revisions

Revision Clause ChangeDescription

Description

1-01

DCN:

00047

General Modification Paragraphs and lists numbered for ease of

referencing

Section 1 Sections reorganised inline with the

ifi ti t l t


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the report.

3.2 Modification Addition of the final bullet point added

3.5.2 a)

I.

Deletion Text deleted (undensified)

3.5.2 Modification I,vi changed from Silica activity index to relative

strength and reference added.

3.6 v. Addition Text added For aggregates comprising volcanic

breccia, mudstone, shale, sandstone, weathered or

altered rocks

Bullet Points added

3.6 Modification Table 8 revised. S3 put in column one for %

passing and S4 replaces S3 for % passing.

3.8.2 e) Addition Text added The Contractor shall test selected

types of accelerators for the range of 2% in 5.0%,

8.0% dosages or the manufacturers recommended

dosage to ensure the short and long term strength

is not impaired and meets the specified

requirements

3.10 Addition Text added (permanent shotcrete only)

4.1 Addition Section 4.1 Inserted

4.2 Modification Witness point added

Section moved from Section 4.1 to 4.2

4.3 vi. Addition Text added (for permanent shotcrete only)

4.4. ( b) Modification

Addition

Text modified and added The target slump(s)

shall be determined by trial mixes with and without

superplasticisers provided the pre production and

production tests show that the sprayed concrete

achieves the short and long term strengths

specified in Table 13 for field tests and productiontests (cores), for sprayed concrete the target slump

shall be;

Without superplasticiser: 80 to 120mm

With superplasticiser: 80 to 150mm


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Note(1)

added clarifying purpose of maximum

strength

Addition of Fire Performance of P3 shotcrete row5.3 Addition (a) text added in first paragraph

Clause 5.3.1 Smoothing Shotcrete section added

6.3 f) Addition Text added however, using a drop pipe to

transfer the concrete from the surface underground

into an agitator truck is acceptable provided the

material does not become overly segregated and

remixing produces a homogenous sprayable mix.

7.1

(Table

14)

Modification Requirement for 1 day tests deleted (as covered by

beam end tests)

Compressive strength test changed to a cylinder

sample

Deletion of Boiled Absorption and Voids Volume

7.1

(Table

15)

Modification Requirement for 1 day test deleted as covered by

Early age compressive strength test

Compressive strength test changed to a cylinder

sample

Boiled absorption test required for permanent

shotcrete only

Flexural strength test method added.

1-02

DCN:

00047

1.1 Addition Addition of text The durability of shotcrete..

1.2 Modification Definition of Silica Fume Concrete has been

modified. Wording used now has been modified

from comment response for clarity.

1.2 Addition Addition of Waterproofing Supervisor definition

1.3 Addition Addition of references to Waterproofing and

Drainage specification and Durability Report


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4.2 Modification Addition of column to Table 11 of P3

Table 11 Modification No change to content but Table has beenreformatted for clarity.

4.4 b Modification Determined has been replaced with confirmed

5.3 Addition Addition of text as required by the

Waterproofing.

5.3.1 Deletion Deletion of 5.3.1 Part b part iii.

5.3.1 Modification Text modified to say manufacturers

6.1 Addition Addition of P3 to 1stparagraph

General Modification Where items have been shown for the approval of

the Designer, this should have referred to theConstruction Certifier. This general error has been

corrected throughout the document.

General Modification Formatting and grammatical errors have been

amended for the IFA / AFC issue.

1.6 Records Maintained by the Contractor

a) General guidelines for records are provided in the General Specification (reference BC-

PBA-GLRSP000-SPC-0001).

b) Records of work methods, listed in Table 6 related to this specification are required to

be submitted by the Contractor to the Construction Certifier in accordance with the

quality system requirements of the Contract.

c) This Specification requires the Contractor to prepare and maintain, as a minimum, the

following documents in accordance with the Contractors Project Quality Plan and make

them available for audit purposes:

i. Proposals to adopt alternative materials and equipment

ii. All information necessary to produce as-built drawings and records

iii. Details of cement for shotcrete, including suppliers details and information todemonstrate compliance with AS 3972


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xi. Results of all acceptance testing and field trials, and results of production testing ofthe shotcrete

xii. The mix design for each type of shotcrete shall be approved by the ConstructionCertifier.

xiii. Records of inspection and written approval of the Temporary and Permanent Worksshall be provided in accordance with this Specification.

2 Quality System Requirements

2.1 General

a) Specific quality system requirements are detailed within PSTS50. Constructionactivities shall be carried out in accordance with the provisions of the Contractors

Quality System which shall comply with the requirements of AS/NZS ISO 9001.

2.2 Hold Points, Witness Points and Milestones

a) The Hold and Witness Points particular to this Specification are listed in Table 3, Table

4 and Table 5 below. Refer General Specification (reference BC-PBA-GLRSP000-SPC-

0001) for Hold Point, Witness Point and Milestone definitions and requirements.

b) The Contractor shall not proceed beyond a Hold Point until the Hold Point has been

released by the person nominated in Table 3. The Contractor shall notify the relevant

person when a Hold Point will be reached so that they can review and/or witness any

work process, record or test being undertaken by the Contractor and thus expedite the

release of that Hold Point.

Table 3 Hold Points

Specification Clause Hold Point Details For Release By

All relevant Hold Points outlined in the

Specifications and Project Deed including the

hold points referred to in the QDMR Project

Specific Technical Standards (PSTS) as

described in Annexure 10 Part 1

IV

Hold Points as the Contractor deems

necessary to meet its obligations under the

Deed.

Contractor

4.3 Approval of shotcrete mix designs and mix

trials (pre-construction tests) including the

proposed curing regime

Construction Certifier

6 2 C tifi ti f l C t t


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Specification

Clause

Witness Point Details For Release By

necessary to meet its obligations under the Deed.

4.1/4.3 Trial Mixes / Field Trials Construction Certifier

5 Surface preparation complete (rock, concrete or

waterproofing)


6.5 Final surface within tolerance Construction Certifier

d) The Contractor shall submit at the time nominated in Table 5, documentary evidence of

Milestones to the Construction Certifier for approval of materials and workmanship as

specified throughout the Specification.

Table 5 Milestones

Specification Clause Milestone Details Timing

4.1 Construction Method Statement 30 days prior to

commencement of work

4.3 Submit proposed shotcrete mix designs 30 days prior to


4.3 Submit results of field trials 30 days prior to


2.3 Work Method Statements

Work Method Statements which are required to be submitted by the Contractor to the

Construction Certifier in accordance with the quality system requirements of the Contract

are listed below in Table 6.

Table 6 Work Method Statements

Specification Clause Work Method Statements

4.1 Construction Method Statement for Tunnel Shotcrete Placement

2.4 Testing Frequency

The minimum testing frequency for work covered by this Specification is specified inClause 7.

2.5 QDMR Registered Suppliers and Products

The use of QDMR registered suppliers and products for the construction of the project

works are required for the items listed in Table 7


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3 Shotcrete Materials

3.1 General

Materials for shotcrete as a minimum must conform to the requirements of this Clause of the

Specification.

3.2 Shotcrete Types

The following shotcrete mixes are specified for this project:

a) Shotcrete Type S1: Steel fibre reinforced shotcrete for temporary support of

excavations. The characteristic cylinder strength of Shotcrete Type S1 at 28 days is40 MPa.

b) Shotcrete Type S2: Steel mesh reinforced shotcrete for temporary support of

excavations. The characteristic cylinder strength of Shotcrete Type S2 at 28 days is

40 MPa.

c) Shotcrete Type S3: Unreinforced shotcrete for temporary support of excavations. The

characteristic cylinder strength of Shotcrete Type S3 at 28 days is 40 MPa.

d) Shotcrete Type S4: Un-reinforced shotcrete for infilling voids and smoothing of surfaces.The characteristic cylinder strength of Shotcrete Type S4 at 28 days is 25 MPa.

e) Shotcrete Type P1: Steel fibre reinforced shotcrete for permanent support of

excavations. The characteristic cylinder strength of Shotcrete Type P1 at 28 days is

40 MPa.

f) Shotcrete Type P2: Steel mesh reinforced shotcrete for permanent support of

excavations. The characteristic cylinder strength of Shotcrete Type P2 at 28 days is

40 MPa.

g) Shotcrete Type P3: Plain Shotcrete shall have monofilament polypropylene fibres in

accordance with Section 3.9. The characteristic cylinder strength of Shotcrete Type P3

at 28 days is 40 MPa.

3.3 Water

a) Water incorporated into shotcrete shall be potable, free from contaminants harmful to

concrete or reinforcement and have electrical conductivity not exceeding 1000 micro-siemens/metre.

b) Water to be used in the manufacture of shotcrete for the Temporary and Permanent

Works shall be of an acceptable quality as defined in Clause 2.4 of AS 1379.

c) Water used for curing, testing water tightness or for other purposes where it may come


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certificates shall cover the period from at least 12 months prior to commencement of the

project. Testing of cement properties in accordance with AS 3972 shall be carried out at

least monthly.

f) Cementitious products shall be supplied only by a QDMR Registered Cement Supplier.

3.5 Supplementary Cementitious Materials

3.5.1 Fly Ash

a) Supplementary cementitious materials Fly Ash and Slag shall comply with AS 3582

Parts 1 and 2 respectively and shall be a QDMR registered fly ash or slag, with the

following modifications:

i. The amount of fly ash retained when wet sieved on a 45 micron sieve shall not

exceed 15% by weight.

ii. Loss on ignition to be not more than 4% by weight.

iii. Specific gravity shall not vary by more than 5%. The uniformity of specific gravity

shall be determined in accordance with Section 17 of ASTM C311.

3.5.2 Microsilica (Silica Fume)

a) Supplementary cementitious material Silica Fume shall comply with AS 3582 Part 3.Silica fume is a latent hydraulic binder which shall comply with the following

requirements:

I. Silica Fume/Dry Powder

i. Bulk density not exceeding 650kg/m3

ii. Silica content shall be not less than 85%

iii. Carbon content of silica fume shall be less than 5%

iv. Particle size shall be between 0.1 and 0.2 microns

v. Fineness: specific surface area shall not be less than 15,000m2/kg

vi. Relative Strength >95% after 28 days. Testing shall be in accordance with

AS3583.6

vii. Moisture content


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i. The nominal maximum particle size shall be 10mm unless approved otherwise by the

Construction Certifier.

ii. The Los Angeles coefficient shall be determined in accordance with sub clause 10.2of AS 2758.1

iii. The magnesium sulphate soundness value determined in accordance with BS EN

1367-2 shall not exceed 18.

iv. The water absorption of the aggregate determined in accordance with AS 1141.6

shall not exceed 2%.

v. For aggregates comprising volcanic breccia, mudstone, shale, sandstone,

weathered or altered rocks the drying shrinkage of the aggregate determined in

accordance with AS 2758.1 shall not exceed 0.075%.

vi. The fines content less than 75 micron determined in accordance with AS 1141.12

shall not exceed 2%.

vii. The aggregate shall be tested for reactivity with the cementitious materials and

admixtures (including accelerators) using the ASTM C1260-01 accelerated mortar

bar method.

viii. Single size aggregates shall be combined in the proportions determined during the

field trials. The individual fractions shall be stored separately.

b) Coarse and fine aggregates shall be free from earth, clay loam and soft clayey, shaley

or decomposed stone, organic matter, friable particles and other impurities and shall be

hard and dense. The grading shall be within the acceptable range according to the

grading given in Table 8 below for wet mix shotcrete.

c) The grading and moisture content of the individual fractions of the aggregate shall bechecked and recorded at least weekly.

d) The Contractor shall maintain for audit purposes details of aggregates and aggregate

sources for shotcrete, including testing and properties of the aggregates.

e) The following aggregates have been tested and confirmed as suitable for use with

polypropylene fibres for permanent shotcrete requiring resistance to fire:

Bromelton North Olivine Basalt,

Beenleigh Meta-Greywacke,

Petrie Greenstone

Narangba Hornfelsed Greenstone.

f) Should the contractor wish to use other aggregates these will require further testing.


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Table 8 Aggregate Grading for Shotcrete

Sieve Size Percent Passing by Weight

S1, S2, S3, P1, P2 and P3 S4

9.5 mm 90 100 -

6.70 mm 80 90 90 100

4.75 mm 70 85 75 90

2.36 mm 50 70 50 75

1.18 mm 35 55 35 55

600 m 20 40 20 40

300m 8 20 8 20

150m 2 10 2 10

75m 0 2 0 2

3.7 Alkali-Aggregate Reaction (AAR)

a) Aggregates intended for use in shotcrete shall not react with alkalis in the concrete that

may result in excessive expansion. The aggregate supplier must provide documentation

of the potential reactivity of the aggregate in accordance with PSTS70 clause 11.1. The

proposed concrete mixes shall meet the innocuous classification of QDMR Test Method

Q458.

3.8 Admixtures

3.8.1 General

b) Admixtures for the purposes of this Specification shall not be used without the approval

of the Construction Certifier.

c) Admixtures shall conform to the requirements of AS1478 and shall be a QDMR

registered admixture.

d) Admixtures to the sprayed concrete mix shall be stated in the Method Statement. The

performance of the modified mix shall be demonstrated by site trials prior to that mix

being used in the Works.

e) All admixtures for shotcrete shall be sourced from a single manufacturer or supplier

where possible to ensure compatibility of admixtures for use in the shotcrete. Where

admixtures are sourced from different suppliers, evidence shall be obtained to


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iii. Variations in the characteristic values of the properties of each admixture

iv. Conditions for storage and handling of admixtures

v. Confirmation of the stability of admixtures with the mix water

vi. Results of testing as required by this Specification for each type of admixture

vii. Confirmation that the additives are safe to use in a tunnel environment and any

safety precautions that are to be taken

3.8.2 Accelerators

a) Accelerators are admixtures. Only liquid accelerators shall be used.

b) Sodium Silicate (Waterglass) shall not be used.

c) Only the minimum quantity of accelerator necessary shall be permitted in normal

shotcreting operations. The quantity shall be determined by field trials, subject to the

maximum dosages specified in Table 9:

Table 9 Maximum Dosages of Accelerator

Shotcrete Type By weight of cementitious material

S1 8%

S2 8%

S3 8%

S4 8%

P1 5%

P2 5%

P3 5%

d) Testing of accelerators in accordance with this Specification with regard to acceleration

of setting, early strength, and decrease of strength at a later age (28 and 90 days), shall

take place in due time before commencement of shotcrete application.

e) The Contractor shall test selected types of accelerators over a range of 2% for 5.0% or

8.0% dosages (See Table 9) but shall not exceed the manufacturers recommendeddosage to ensure the short and long term strength is not impaired and meets the

specified requirements. Laboratory testing of the selected type(s) of accelerator shall

be carried out in accordance with this Specification at dosages of 5.0% and 8.0% for

non-caustic, alkali free accelerators by weight of cementitious material in the base

concrete, or similar dosages as recommended by the manufacturer, to establish the


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plasticisers and retarders shall be determined during development of the mix design

and/or by field trials in accordance with this Specification.

c) Plasticisers and retarders shall not contain calcium chloride.d) Compatibility of plasticisers and retarders with cements, latent hydraulic binders and

accelerators shall be verified by observation during development of the mix design

and/or in the field trials.

e) Plasticisers and retarders shall be used in accordance with the manufacturers

instructions.

3.8.4 Hydration Control Admixtures

a) Hydration control admixtures may be used with Shotcrete Types S1, S2, S3, P1, P2 andP3 in accordance with this Specification and subject to the approval of the Construction

Certifier. Hydration control admixtures used with accelerator in Shotcrete Type S1, S2,

S3, S4, P1, P2 and P3 shall not cause a decrease in strength with age.

b) Hydration control admixtures may be used to control the hydration of the mix as

appropriate to expedite construction of the Temporary and Permanent Works. The

effects and optimum dosages of hydration control admixtures shall be determined by

field trials in accordance with this Specification.

c) Hydration control admixtures that delay the setting process by greater than 10 hours for

Shotcrete Type S1, S2, S3, S4, P1, P2 and P3 shall not be used. Proposals to use

hydration control admixtures for longer periods may require additional field trials and/or

testing as specified by the Construction Certifier.

d) Compatibility of hydration control admixtures with cements, latent hydraulic binders and

accelerators shall be verified by observation in the field trials.

e) Hydration control admixtures shall be used in accordance with the manufacturer'sinstructions.

3.9 Fibres

3.9.1 General

a) Fibres may be collated with fast-acting water-soluble glue, or may be uncollated

individual fibres. Water-soluble glue or other additives used to collate fibres shall be

compatible with other shotcrete components.

b) Fibres shall be stored in dry sealed containers until ready for use and shall be free from

corrosion, oil, grease, chlorides and deleterious materials which may reduce the

efficiency of mixing or spraying processes, or which may reduce the bond between the

fibres and the shotcrete. Containers of fibres shall be stored in areas protected from the

weather and extremes of heat as per the manufacturers instructions.


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3.9.3 Synthetic Fibres (Structural)

a) Synthetic fibres shall be of the structural macro-synthetic type of fibre in accordance

with BS EN 14889-2 and of greater than 0.3mm diameter. The fibre shall have a

textured surface and be produced from polyolefin or a similar base resin material. .

3.9.4 Synthetic Fibres (Fire)

a) Synthetic Fibre may be used in Shotcrete Type P1, P2 or P3 to achieve the specified

design requirements for the fire load case.

b) Micro-synthetic fibres shall be 18-32 micron monofilament PP fibres specifically

manufactured for use as a concrete additive and so certified by the manufacturer, and

containing no reprocessed olefin materials.

c) Alternative monofilament PP fibre dimensions may be proposed provided they have test

data to demonstrate they have equivalent fire performance criteria as the 18-32 micron

fibres.

d) The required dosage and effectiveness of fibres in reducing concrete spalling due to

exposure to fire shall be assessed by the Concrete Fire Testing Specification (reference

BC-PBA-GLSSP414-SPC-0001).

3.10 Soluble Salts (permanent shotcrete only)

a) The chloride ion content of the hardened shotcrete must be tested in accordance with

AS1012.20. A representative sample of at least 20 grams of crushed and ground

shotcrete shall be used, with the titrating solution being 0.01 to 0.02N. For the test, use

the Volhard method calibrated using a concrete with known chloride content.

b) The mass of acid-soluble chloride ion per unit volume of permanent shotcrete as placed

must not exceed the values given in Table 10.

c) The sulphate content of shotcrete, determined by calculation and expressed as thepercentage by mass of acid-soluble SO3 to cement, must not be greater than 4.0%.

Table 10 Maximum Values of Acid-Soluble Chloride-Ion Content in Shotcrete

Exposure *

Classification

Maximum acid-soluble ch loride ion con tent (kg/m)

Fibre Reinforced Concrete or Conventional Reinforced Concrete

A 0.8

B1 0.8

B2 0.8

Note: Chloride ion content may be expressed in percentage weight of oven dried concrete.

(0.1 kg/m3ion content is approximately equivalent to 0.004% by weight of oven dried

concrete) *For information on exposure classifications see AS 5100 5


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iv. Proposed methods for Surface Preparation

v. Proposed methods for use of steel reinforcement and other embedments where

applicablevi. Proposed methods and equipment for mixing, conveying and applying shotcrete

vii. Details of procedures for monitoring of shotcrete thickness, including spacing of

depth indicators (if applicable) and details of how the profile is to be maintained.

viii. Repair procedures, including proposed mix designs for core hole repair

4.2 Mix

a) Mix designs shall comply with the requirements shown in Table 11. Witness Point.

Table 11 Particular Mix Requirements

Parameter Shotcrete Type

S1 S2 S3 S4 P1 P2 P3

Steel Fibre

- minimum tensile strength (MPa)

- minimum length (mm)

- maximum length (mm)

- minimum content (kg/m3)

900

25

50

30

N/A

N/A

N/A

N/A

900

25

50

30

N/A

N/A

N/A

N/A

Cementitious Material Type GP or GB** with microsilica

Minimum Cementitious Content

(kg/m)400

Maximum Water * : CementitiousContent Ratio

0.45

Accelerator Type Non-caustic, alkali free

Silica Fume Content 5-10%

(4-8% when used with Type GP or GB)

* Water shall include the liquid content of liquid admixtures

** Fly ash content not to exceed 15% by weight. Care should be taken in the choice of cementitiousmaterials to ensure that sufficient lime is available for reaction with the silica fume.

b) Shotcrete shall be applied by the wet mix process and be capable of being applied in

layers up to 150 mm in thickness with good adhesion to the ground or previous layers of

shotcrete without sagging or slumping.


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vi. Flexural strength (for permanent shotcrete only); and

vii. Flexural Toughness.

b) Field trials shall be started sufficiently early to ensure that the required shotcrete mixesare developed and all trials completed satisfactorily by the time shotcreting of each

Shotcrete Type commences in the Temporary and Permanent Works. Shotcreting of

any Shotcrete Type shall not commence until the relevant trials have been completed,

and the results of the field trials and acceptance testing submitted to the Construction

Certifier for approval at least 30 days prior to the commencement of Shotcreting Hold

Point 1 Witness Point Milestone.

c) The field trials shall employ the types of equipment which will be used in the Temporaryand Permanent Works and the constituent materials shall be fully representative of

those to be used in the Temporary and Permanent Works.

d) Each field trial shall be a witness point with a notice period of three (3) days.

e) As an alternative to field trials the Contractor may adopt a proven shotcrete mix design

with a test history of at least 12 months that demonstrates compliance with the

requirements of this Specification to be submitted for approval Milestone.

f) If field trials are required, testing for field trials shall be in accordance with Table 12.

Table 12 Testing Methods Field Trials

Test Method

Compressive Strength (cast sample) AS 1012.8 and AS 1012.9

Compressive Strength (cored sample) AS 1012.14

Flexural Toughness (Round Panels SFRC Only) ASTM C1550-03a

Fibre (SFRC only) This Specification

4.4 Sprayed Concrete Trials

a) From the field trial mix an experienced nozzleman shall prepare sufficient test panels.

Panels for coring shall be at least 1000 x 1000mm in size and shall be 200mm thick.

The panels shall be prepared by shotcreting into rigidly supported vertical moulds.

Moulds shall be constructed of steel or other non-water absorbing rigid materials. Theupper and lower edges of the mould shall have parallel sides splayed outwards at 45

degrees to the back face to prevent the entrapment of rebound. The vertical edges of

the mould shall have parallel sides at 90 degrees to the back face to facilitate coring

perpendicular to the spray direction. Round panels for flexural toughness testing shall

be 800 10mm diameter and 75 15mm thick, and prepared by shotcreting into rigidly


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The cores for 7, 28 and 90 day strength tests shall be stored in water in accordance

with AS 1012. Round panels for flexural toughness testing shall be stored in water in

accordance with AS 1012.

d) Cylindrical test specimens shall be cored from each test panel and tested as listed

below. Drilling of test specimens shall be in accordance with AS 1012.14. Drilling of

cores shall be located to avoid areas of possible rebound. No two cores to be tested at

any given age shall come from the same panel. Cores to be tested at different ages (i.e.

1, 7 and/or 28 days) may come from the same panel. For each test at least one spare

specimen shall be provided. The testing requirements and core dimensions shall be:

i. Compressive strength in spray direction after 1, 28 and 90 days on 4 cores each.

The prepared test cores shall be 75mm diameter and 150mm long (minimum).

ii. Compressive strength perpendicular to spray direction after 1, 7, 28 and 90 days on

4 cores each. The prepared test cores, to be taken from different panels, shall be 75

mm diameter and 150 mm long (minimum).

e) Each cored cylinder or round determinate panel shall be marked with an appropriate

reference mark and the date and time of shotcreting.

f) Steel fibres used shall have a minimum tensile strength of at least 900 MPa

g) Setting times shall be observed during the field trials in accordance with BS EN 196-3.

h) Optimum fibre content shall be determined dependent on ease of use in the batching,

mixing, and shotcreting processes proposed, and from the results of the tests to

determine flexural toughness by the testing of round determinate panels.

i) The compressive strength of shotcrete cores from test panels shall be acceptable if the

compressive strength results both for samples with their axes parallel to the direction of

spraying and for samples with their axes perpendicular to the direction of spraying,comply with the minimum performance requirements set out in this Specification. One

test result shall consist of the mean of three core strengths (a spare specimen shall be

taken but not tested). Seven day results shall be used for indicative purposes only. The

compressive strength of cores in steel fibre reinforced or plain shotcrete shall be

deemed to be the in situ cylinder strength provided that the specified requirements are

met in terms of core diameter and height: diameter ratio.

j) A minimum of three successful Round Panels tests that meet the specification in Table

13 are required for each shotcrete mix.

k) The Contractor shall carry out such other tests and trials during the period of the field

trials as may be necessary, to confirm that proposed mixes and methods meet the

minimum performance requirements and particular mix requirements of this

Specification.


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4.5 Submission Details

a) The Contractor shall submit details of each shotcrete mix design for approval to the

Construction Certifier at least 30 days prior to the commencement of shotcreting works.The submission shall include, as a minimum, the following information:

I. Mix Design

i. The name of the concrete supplier and the proposed methods and degree of

quality control

ii. Types and proportion by mass of various materials comprising the mix,

including chemical admixtures and supplementary cementing materials

iii. A copy of the Quarry Assessment Certificate for each material source

iv. Target strength

v. Trial mix water/cement ratio and corresponding nominated water/cement ratio.

vi. Slump of the trial mix and corresponding nominated slump

II. Trial Mix

i. Number and sizes of test panels

ii. Base mix used in each test panel

iii. Type and dosages of nozzle-added admixtures

iv. Required and actual thickness

v. Description of finished product

vi. The degree of control required to achieve uniform shotcrete without excessiverebound, sloughing, partial or total collapsing during shotcreting.

b) This constitutes a hold point for each different shotcrete mix used in the works covered

by this Specification.

4.6 Performance

The performance requirements are shown in the Table 13.

Table 13 Minimum Performance Requi rements for Shotcrete

Parameter Test Method or

Clause No

Shotcrete Type

S1 S2 S3 S4 P1 P2 P3

Min Mean Insitu Cylinder

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Determinate Panels)

at 1.0mm deflection

at 5.0mm deflection

at 20mm deflection

at 40mm deflection

ASTM

C1550-03a

12 J

62 J

211J

282J

N/A 12 J

62 J

211J

282 J

N/A

Dry Density

[All tests at 28 days]AS 1012.8 2150 to 2400kg/m

Boiled Absorption (max. %)

[All tests at 7 days] (for

permanent shotcrete only)

AS 1012.21 8% max

Apparent Volume of

Permeable Voids (max. %)

[All tests at 7 days] (for

permanent shotcrete only)

AS 1012.21 17% max

Early Age Compressive

Strength

Beam End Test

(**)1.0MPa before personnel re-entry into heading.

Shrinkage Strain (forpermanent shotcrete only)

AS1012.13 N/A 850 microstrainafter 8 weeks

drying

Permeability (for permanent

shotcrete only)

DIN1048

Part 5

N/A 25mm

maximum

penetration

Fire Performance of P3

shotcrete

Permanent shotcrete with 2kg/m3 dosage of

polypropylene fibres made from aggregates listedin Section 3.6. A lower dosage may be

acceptable if fire tests using the same concrete

mix, fibres and aggregates meet the fire

performance requirements.

* Tests used for indicative purposes only.

** Refer to section 11.4.4 Concrete Institute of Australia, Recommended Practice Shotcreting inAustralia

+ Compressive Test at 1 day may be stopped depending on compliance and as approves by the

Construction Certifier.

++ Compressive Tests at 90 days are only required if hydration control admixtures are included in the

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adhesion of the sprayed concrete to the excavated surface. The surface to receive shotcrete

shall be damp and without free water prior to application of sprayed concrete.

Action shall be taken as necessary to control ground water and prevent it adversely

affecting the sprayed concrete lining. Water inflows which might cause deterioration of the

concrete, or prevent adherence, shall be diverted by channels, chases, pipes or other

appropriate means to the invert or to the ground water drainage system.

Where necessary, pressure relief holes shall be provided through the primary lining to

ensure that no hydrostatic pressure develops behind the lining.

5.2 Preparation of Shotcrete / Concrete Surfaces

Existing shotcrete/concrete surfaces to be shotcreted shall be cleaned of any spalled,cracked, deteriorated, loose, unsound and/or chemically contaminated shotcrete/concrete

until a sound and uncontaminated shotcrete/concrete is reached. Water blasting, chipping,

scabbling or other mechanical means shall be used to remove any contaminated shotcrete/

concrete Witness Point.

Where reinforcement is exposed, it should be free from loose rust, scale or other deleterious

matter likely to effect durability and bonding.

Where shotcrete is to be placed against a smooth concrete surface, the surface shall beroughened by mechanical methods or by water blasting.

After the above preparation is carried out, the concrete surface shall be pre-wetted prior to

the application of shotcrete and any excess water shall be removed.

5.3 Preparation for Installation of Waterproof Membrane

a) Prior to fixing either a separation or waterproof membrane, a survey of the initial

shotcrete lining shall be performed to confirm the correct profile of the lining. Anyremedial measures required to correct out of tolerance profiles shall be undertaken in

accordance with approved Method Statements as required by the Waterproofing

Supervisor in accordance with specification (reference BC-PBA-GLTSP107-SPC -0001)

b) Where shotcrete is to be applied to a substrate comprising either a pre-formed sheet

membrane or a spray-on waterproof membrane the surface shall be prepared strictly in

accordance with the manufacturers recommendations and the relevant work method

statement. On no account shall SFRS be sprayed directly onto sheet membrane, unless

the membrane manufacturer can provide a guarantee that this will not damage themembrane.

5.3.1 Smoothing Shotcrete (Type S4)

a) Smoothing shotcrete shall conform to the general requirements of PSTS04 with respect

t t i l d k hi

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iv. Large circumferential irregularities shall not exceed 200 mm when measure from a

1.0 m curved edge held against the tunnel circumference.

v. Any curvature or irregularity shall have a radius greater than 200 mm.

vi. The shotcrete shall be cured for at least 24 hours prior to membrane application.

vii. Steel elements, such as reinforcement bars, steel fibres, steel girders and the

heads of rock bolts (as far as not used to hold inner lining structures) shall be

covered with at least 20mm of shotcrete.

viii.Running water ingress shall be plugged prior to the final lining. Heavy water ingress

can be collected into half-pipes (or flexi-drain or strip-drains or similar), mounted by

nailing and led into the permanent drainage system. The mounted half-pipe should

be covered with at least 20mm of shotcrete prior to the initial temporary works

shotcrete lining installation.

ix. Where water is found to be penetrating through the shotcrete lining at a rate that

may adversely affect the installation of membrane, the water shall be collected by

means of hoses and drained to the tunnel invert. The drainage shall be maintained

during the membrane installation process so that no water pressure can develop

behind the membrane.

x. Inspection and acceptance shall be required in accordance with the approved

Contractors construction work method statement.

xi. The shotcrete smoothing layer shall be completed using a maximum aggregate size

of 4mm unless it can be demonstrated that a coarser aggregate can achieve a

surface compatible with the membrane manufacturers recommendations.

Shotcrete surface shall be at least 28 days old prior to the application of spray

applied membranes.

6 Application of Shotcrete and Curing

6.1 Equipment

a) Only wet mix process equipment shall be used for Shotcrete Types, S1, S2, S3, S4, P1,

P2 and P3. Equipment for the wet mix process shall be set up according to the

recommendations of the manufacturer. Pumping equipment shall ensure the continuous

conveyance of shotcrete at a steady and quantifiable rate with minimal pulsation. Theequipment shall allow for air and water in any combination to be available for

preparation of surfaces and/or cleaning of finished work in accordance with this

Specification.

b) All equipment used for batching and mixing of materials, and the transport and



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e) Equipment shall be thoroughly cleaned at least once per shift, or more frequently at

appropriate intervals if hydration control admixtures are used, to prevent accumulations

of residual deposits and/or deterioration due to the accelerators used.

f) Transport pipes consisting of hoses or pipes shall be laid straight or in gentle curves.

The transport pipes shall have a uniform diameter appropriate to the mix and fibre

characteristics determined by field trials, and be free of any dents or kinks between the

shotcrete machine and the nozzle.

g) Equipment shall allow application of shotcrete to all surfaces with the nozzle at the

distances from the surfaces to be sprayed in accordance with this Specification.

h) Working areas for shotcreting shall be well illuminated. Cap lamps attached to safety

helmets will not be accepted as sufficient illumination. Dust pollution shall be minimised

by choice of appropriate equipment and by means of additional ventilation, water

sprays, and by maintaining equipment in good order.

i) Dosing of admixtures by hand is not permitted. Each machine provided for the wet mix

process shall incorporate:

i. A memory programmable control system to coordinate and control all functions of

the machine including the dosing of all admixtures.

ii. An integrated proportioning unit to dispense admixtures at the required dosages as

controlled by the throughput of concrete. The equipment shall be capable of

delivering admixtures such that the approved dosages are dispensed to an

accuracy of 0.5% of the required dosage and shall be calibrated and operated in

accordance with the manufacturer's instructions.

j) As far as practicable all shotcrete shall be applied using remote controlled spraying

equipment appropriate to particular applications. Hand spraying of wet mix shotcrete is

permitted.

k) Remote controlled spraying equipment shall be provided with as long reach as possible.

This shall ensure that the operator can observe the nozzle at all times during spraying

from a position of safety under supported ground. The controls shall provide the

operator with full and effective control of the nozzle articulation and other functions. The

equipment shall be used, cleaned and maintained in accordance with the

manufacturer's instructions.

6.2 Proficiency of Nozzlemen

a) Nozzlemen shall have had previous experience and be proficient in the application of

shotcrete. Production shotcrete shall be applied only by nozzlemen who have

demonstrated their competence and their ability to produce either plain or steel fibre

reinforced shotcrete by the method to be used Nozzlemen shall hold certificates of



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p | y |GL - Supplementary Specification - Tunnel - Shotcrete Lining GLTSP102

c) Regular checks shall be made to ensure that complete mixing is routinely achieved.

Tests for mix consistency shall be in accordance with ASTM C94-04 or similar approved

international standard.

d) The addition of fibres shall be at a stage in the mixing suitable for the shotcreting

equipment. The procedure for the addition of fibres shall be determined during the field

trials. Fibres shall be added and mixed in a manner to avoid clumping and bending of

the fibres. Any fibre clumps in the mix shall be diverted and removed by means of a

screen placed over the shotcrete hopper. Fibres shall be uniformly distributed

throughout the mortar matrix without isolated concentrations. Fibres shall not be added

to the mix at a rate faster than that at which they can be blended with the other

ingredients without forming balls or clumps.

e) The mixed base concrete for the wet mix process shall be applied within one and a half

(1.5) hours of charging the mixer. This time may be extended by the use of retarders,

plasticisers or hydration control admixtures in accordance with this Specification.

f) The base concrete for shotcrete produced by the wet mix process shall be transported

by truck mixers, concrete pumps or other suitable containers and shall prevent

segregation or possible loss or gain of water. Remixing of material shall not be

permitted, however, using a drop pipe to transfer the concrete from the surface

underground into an agitator truck is acceptable provided the material does not becomeoverly segregated and remixing produces a homogenous sprayable mix. The mixture

shall be effectively protected against any influence of the weather.

6.4 Application

The following requirements shall be achieved prior to and during the application of the

shotcrete:

a) Method statement and procedures have been submitted and approval has been givenby the Construction Certifier.

b) Checking and correction of the excavated cross section profile shall be carried out and

rock surfaces and/or existing shotcrete shall be cleaned with compressed air and, as far

as the local conditions permit, with an air-water mixture as necessary to remove all

material which may prevent proper adhesion of the shotcrete to the surface. The

surface to receive shotcrete shall be damp, but without free water prior to the

application of shotcrete. Treatment with an air-water mixture to ensure that the surface

is sufficiently clean and damp shall be done shortly before the application of shotcrete.

c) Action shall be taken to control groundwater and prevent it adversely affecting the

shotcrete lining. Adopted measures shall remain effective for at least 28 days. Water

inflows which might cause deterioration of the shotcrete, or prevent adherence, shall be

diverted as detailed on the Drawings or otherwise proposed by the Contractor by



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| |GL - Supplementary Specification - Tunnel - Shotcrete Lining GLTSP102

h) Each layer of shotcrete shall be built up by making several passes of the nozzle over

the working area using good working practices and nozzle manipulation. The shotcrete

shall emerge from the nozzle in a steady uninterrupted flow. Should the flow become

intermittent for any cause the nozzleman shall direct it away from the work until it againbecomes constant.

i) Where a layer of shotcrete is to be covered by succeeding layers, it shall first be

allowed to set and loose material and rebound shall be removed. The surface shall be

checked for soundness, repaired as specified, finally cleaned, and wetted using a blast

of air and water.

j) No rebound material shall be covered with shotcrete. All rebound material shall be

removed from the working area and shall not be used in the Temporary and PermanentWorks. Disposal shall be undertaken with proper regard to the risks of environmental

pollution by both the cementitious materials and/or the admixtures.

k) For vertical and near vertical surfaces application shall commence at the bottom. Layer

thickness shall be governed mainly by the requirement that the material shall not sag.

Where thick layers are applied the top surface shall be maintained at a slope of

approximately 45 degrees. For overhead surfaces shotcrete shall preferably be applied

from the shoulder to the crown.

l) Pockets, sags or other defects shall be cut out and resprayed. The area of respraying

shall not be less than 300mm x 300mm.

m) Unless specifically required and appropriate mixes designed, finishing actions, such as

trowelling or screeding, shall be avoided and may require remedial works to be

undertaken.

n) The temperature of the mix before spraying shall not be below 5C or above 35C

unless special provisions are made to the approval of the Construction Certifier.Spraying shall not be undertaken when the ambient temperature is below 5C.

o) Sprayed concrete shall not be applied in the Temporary and Permanent Works until the

correct setting characteristics are observed during the start-up and a continuous

shotcrete stream is ejecting from the nozzle.

p) Where two layers of reinforcement are used, the far face reinforcement shall be covered

by sprayed concrete before the near layer is installed. The near layer shall be covered

by sprayed concrete up to the required thickness with the minimum delay.

6.5 Thickness and Profile Control

a) Where specified on the Drawings the minimum layer thickness shall be controlled by

depth pins attached to the rock bolt plates or lattice girders. Depth pins shall be used at

f f l k 2 d Wh ifi d h



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GL - Supplementary Specification - Tunnel - Shotcrete Lining GLTSP102

6.6 Curing

a) All final surfaces of shotcrete Types S1, S2, S3, S4, P1, P2 and P3 need not be subject

to special measures unless the results of testing indicate that the performancerequirements of this Specification are not being consistently achieved and that such

underperformance is attributable to poor curing, in which case the Contractor shall

make a proposal for curing the shotcrete for acceptance by the Construction Certifier.

7 Shotcrete Testing

7.1 Production Tests

b) Tests shall be carried out on a routine basis on cores or other samples taken fromshotcrete placed in the tunnels and shafts, or from panels prepared for test purposes.

c) Specimens shall be tested in accordance with the following clauses. The tests shall be

carried out as specified in Table 14 for temporary and Table 15 for permanent shotcrete

lining.

d) The frequency of carrying out each production test on specimens taken from shotcrete

placed in the tunnels and shafts is given in the following Clauses of this Specification.

The dimensions of test specimens shall be as specified elsewhere in this Specification.e) Where cores are to be taken from the tunnels and shafts, and where the nominal

required shotcrete thickness is less than 100mm the cores for compressive strength or

other testing requiring specimens longer than 100mm shall be taken from areas where

the actual thickness is greater than 100mm. Alternatively, additional shotcrete thickness

shall be applied in selected areas for subsequent coring of test specimens.

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Table 14 Test Methods Production Testing for Temporary Shotcrete Lining

Performance Criteria Test Method Test Frequency


StrengthBeam End Test

One (1) for every 100m3sprayed shotcrete.

Minimum 1.0MPa compressive strength before

man entry. For each site one (1) test a day for

first two (2) weeks and afterwards one (1) test a

month.

Compressive Strength

(cored sample)AS 1012.14

For each 100m3sprayed shotcrete three (3)

cores each for:

7day

28day

90day


(cylinder sample)

AS1012.8.1

AS1012.9

For each 100m3sprayed shotcrete three (3)

cylinder samples each for:

7day

28day90day

Flexural

Toughness(Panels, SFRS

only)

ASTM C1550

Three (3) panels from the same shotcrete batch

for each 250m shotcrete

Dry Density (cored

sample)

AS 1012.12 and AS

1012.14

Three (3) tests on three (3) specimens from 7 or

28 day old shotcrete for each 250m3

Dry Density (cast sample) AS 1012.8 Three (3) tests on three (3) specimens from 7 or28 day old shotcrete for each 250m

3

Fibre Content (SFRS

only)BS EN 14488.7

One test (meaning the average of tests on 3

specimens) for each 250m3

SlumpAS 1012.3 and AS

1379

For every 50m3produced after the addition of

plasticiser for each load delivered.

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Table 15 Test Methods Production Testing for Permanent Shotcrete Lining

Performance Criteria Test Method Test Frequency


StrengthBeam End Test

One (1) for every 100m3sprayed

shotcrete.

Minimum 1.0MPa compressive strength

before man entry. For each site one (1)

test a day for first two (2) weeks and

afterwards one (1) test a month.


(cored sample)AS 1012.14

For each 100m3sprayed shotcrete three

(3) cores each for:

7day

28day

90day


(cylinder sample)

AS1012.8.1

AS1012.9

For each 100m3sprayed shotcrete three

(3) cores each for:

7day

28day90day

Flexural Toughness(Panels,

SFRS only)ASTM C1550

Three (3) panels from the same shotcrete

batch for each 250m shotcrete

Dry Density (cored sample)AS 1012.12 and AS

1012.14

Three (3) tests on three (3) specimens

from 7 or 28 day old shotcrete for each

250m3

Dry Density (cast sample) AS 1012.8Three (3) tests on three (3) specimensfrom 7 or 28 day old shotcrete for each

250m3

Boiled Absorption

(permanent shotcrete only)AS 1012.21

Three (3) tests on three (3) specimens

from 7 or 28 day old shotcrete for each

250m3

Fibre Content (SFRS only) BS EN 14488.7One test (meaning the average of tests on

3 specimens) for each 250m3

Slump AS 1012.3 and AS 1379

For every 50m3produced after the

addition of plasticiser for each load

delivered.

Permeability DIN1048Minimum two (2) cores per one (1) weeks



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GL Supplementary Specification Tunnel Shotcrete Lining GLTSP102

b) Depending on the compliance of test results with this Specification, circumstances of

application and importance of construction, the frequency may be reduced to every

250m3 or increased to every 50m3 as approved by the Construction Certifier. The

cores shall be cored through the whole thickness of the shotcrete and visually inspectedto verify that the shotcrete is dense and homogeneous without segregation of aggregate

and/or fibre or other visible imperfections.

c) Tests for 1 day strength shall be carried out at 24 hours 2 hours and for 7 day and 28

day and 90 day strength when required in accordance with AS 1012.14.

d) Instead of testing cores taken from shotcrete placed in the Temporary Works, indirect

test methods may be used to determine the 1 day strength. Results of indirect tests

shall be correlated to the 1 day in situ cylinder compressive strengths.e) The strength of shotcrete measured by cores taken from the Temporary and Permanent

Works, shall be acceptable if the compressive strength results comply with the minimum

performance requirements. One test result shall consist of the mean of three core

strengths. Seven day results shall be used for indicative purposes only. The

compressive strength of cores in steel fibre reinforced or plain shotcrete shall be

deemed to be the in situ cylinder strength provided that the specified requirements are

met in terms of core diameter and height: diameter ratio.

7.3 Flexural Toughness Test

a) Tests to determine flexural toughness by the testing of round panels shall be carried out

in accordance with ASTM C1550.

b) Panels shall be clearly marked to identify the time, date and location of spraying. Panels

shall not be moved for 18 hours after spraying and shall be cured and protected.

c) Frequency of round panel testing shall be three (3) tests on panels (prepared from the

same shotcrete batch) for each 250 m3of each Shotcrete Type S1 and P1 placed.

d) Shotcrete shall be acceptable if the results from round determinate panel toughness

testing are derived in accordance with ASTM C1550 and the results from at least 2 out

of 3 panels tested for each test exceed the minimum requirements of this Specification.

e) Samples for flexural toughness tests shall be taken from the same shotcrete as samples

for testing of steel fibre content (see Section 7.5). If four successive flexural toughness

tests demonstrate compliance with this Specification, and show a correlation with the

results of steel fibre content tests then, subject to approval of the Construction Certifier,further testing for flexural toughness is not required.

7.4 Dry Density, Boiled Absorption and Voids Volume

a) Dry density, boiled absorption and voids volume shall be determined for shotcrete



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G Supp e e a y Spec ca o u e S o c e e g G S 0

c) The shotcrete shall be acceptable if the average result of the three tests exceeds the

specified minimum requirements and no individual result is less than the specified

minimum by more than 20%.

7.6 Slump

a) The slump of Shotcrete Types S1, S2, S3, P1, P2 and P3 shall be measured in

accordance with AS 1012.3 and AS 1379 after the addition of fibre (where required) and

plasticiser to the required dosages.

b) Shotcrete shall be acceptable if the slump is within the range nominated for the

approved shotcrete mix design.

7.7 Test of Steel Fibre

a) Tests on steel fibre shall be in accordance with ASTM A820-04 except that the cross

sectional area used to compute the tensile strength shall be calculated to four decimal

places, in units of square millimetres, and shall be:

i. For drawn wire fibres, the area calculated from the actual diameter of the parent

source material or finished fibres

ii. For cut sheet fibres, the area calculated from the actual thickness and width of theparent source specimen, or if fibres are tested, the area of each individual fibre

calculated from the measured length and weight of the fibre, weighed to the nearest

0.0001 g, based on a density of 7,85 0kg/m3

iii. For melt-extraction fibres, the area calculated from the equivalent diameter of the

fibres, computed from measured average length and the weight of a known quantity

of fibres, based on a density 7,850 kg/m3

8 Repair of Shotcrete8.1 General

a) Before repairing shotcrete, all test results as specified in Clause 7 shall be submitted for

approval unless where it is deemed by the Contractor the safety of the Works and

persons is endangered then shotcrete shall be repaired immediately Hold Point 3.

8.2 Core Hole Repair

a) The core holes/reamed holes shall be cleaned thoroughly with all loose material or

material that otherwise has the potential to break away, scaled back and refilled with dry

pack mortar

9 Remedial Works to Non-Conforming Shotcrete



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pp y p g

c) If the indicated non-compliance(s) may reduce unacceptably the stability or

serviceability of the Temporary and Permanent Works and are detrimental to the

effectiveness of the Temporary and Permanent Works, the Contractor shall either:

i. Remove the defective shotcrete in strips or panels in such a way that the safety ofthe Temporary and Permanent Works and persons is not endangered, and replace

with shotcrete that is acceptable, or;

ii. Alternatively, if reviewed and recommended by the Construction Certifier, additional

shotcrete may be applied, or;

iii. Other repair methods recommended by the Construction Certifier

9.2 Compressive Strength Failures

a) If the strength requirements at 28 days are not met during the testing process, the

following actions are to be undertaken:

i. Inform the Construction Certifier

ii. Cores to be taken from the tunnel support

iii. Determine the non-conforming area

iv. Cores to then be tested and if they fail to meet the requirements of the Specification

then prepare proposals for strengthening of the area in cooperation with the


v. The Contractor shall submit a remedial works proposal to the Construction Certifier

for review

vi. Repair the area by the method agreed with the Construction Certifier.


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Appendix A

Verification Records


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Appendix B

Response to Comments


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No. Name Discipline Area-Organisation Document Revision Reference Reviewer CommentRating

ImpactIV Status TJH Comment Designer response

Response

agreementIncorporation status

12 Andrew Axton CNI Report-General It is not evident from the report whether the comments from the previous issue of this

DCN have been addressed These comments were issued under TRIM ref: 10/18239

Comment added 07/04/10. It would

appear from the comment sheet that

19-5-10 CLOSED-

Conditionalof

N/A

VL16B 1-02


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DCN have been addressed. These comments were issued under TRIM ref: 10/18239

12 March 2010 (letter reference 10/20116). Please address this issue

appear from the comment sheet that

the IV considers the items have been

included and closed with the

exception of Item 11.

Conditional of

incorporation of

designer response

13 Andrew Axton CNI Report Section 5.3.1(b) It is noted that item (iii) and item (xi) contradict each other with respect to aggregate

size. Please address this discrepancy.

Comment added 07/04/10. Comment agreed. It em iii has

been deleted to remove the discrepancy

19-5-10 CLOSED-

Conditional of

incorporation of

N/A

IV Status

* Means Response acceptable - w il l be c losed when completed

Y Means Complies with Project requirements

N Means Does not comply with Project requi rements

M Means Minor non compliance with Project Requirements

N/A Means Not Applicable to this design lot

Transmittal Stage Doc Number Revision Area Element Title

Review Comment External-IV-CNI

Documents

Specification - Tunnel Shotcrete Lining