EN 1536:2010

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Ausführung von Arbeiten im Spezialtiefbau - BohrpfähleExécution des travaux géotechniques spéciaux - Pieux forésExecution of special geotechnical work - Bored piles93.020Zemeljska dela. Izkopavanja. Gradnja temeljev. Dela pod zemljoEarthworks. Excavations. Foundation construction. Underground worksICS:Ta slovenski standard je istoveten z:EN 1536:2010SIST EN 1536:2011en,de01-februar-2011SIST EN 1536:2011SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 1536
September 2010 ICS 93.020 Supersedes EN 1536:1999English Version
Execution of special geotechnical work - Bored piles
Exécution des travaux géotechniques spéciaux - Pieux forés
Ausführung von Arbeiten im Spezialtiefbau - Bohrpfähle This European Standard was approved by CEN on 2 July 2010.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1536:2010: ESIST EN 1536:2011

2 Contents Page Foreword .41 Scope .52 Normative references . 103 Terms and definitions . 114 Information needed for the execution of the work . 164.1 General . 164.2 Special features . 165 Geotechnical investigation . 175.1 General . 175.2 Specific requirements . 186 Materials and products . 196.1 Constituents . 196.1.1 General . 196.1.2 Bentonite . 196.1.3 Polymers . 196.1.4 Cement . 196.1.5 Aggregates . 206.1.6 Water . 216.1.7 Additions . 216.1.8 Admixtures . 216.2 Support fluids . 216.2.1 Bentonite suspensions . 216.2.2 Polymer solutions . 226.3 Concrete . 236.3.1 General . 236.3.2 Aggregates . 236.3.3 Cement contents . 236.3.4 Water/cement ratio. 236.3.5 Admixtures . 246.3.6 Fresh concrete . 246.3.7 Production of concrete . 256.3.8 Sampling and testing on site . 256.4 Grout . 266.5 Reinforcement . 266.6 Additional inserted products . 277 Considerations related to design . 277.1 General . 277.2 Piles forming a wall . 287.3 Excavation . 287.4 Precast concrete elements . 297.5 Reinforcement . 297.5.1 General . 297.5.2 Longitudinal reinforcement . 297.5.3 Transverse reinforcement . 307.6 Steel tubes and profile elements . 317.7 Minimum and nominal cover . 318 Execution . 328.1 Construction tolerances . 328.1.1 Geometrical tolerances . 32SIST EN 1536:2011

Glossary. 57Annex B (informative)
Examples for details and frequencies for monitoring and testing . 65Annex C (informative)
Sample records . 70Annex D (informative)
Obligation of the provisions . 77Bibliography . 82
4 Foreword This document (EN 1536:2010) has been prepared by Technical Committee CEN/TC 288 “Execution of special geotechnical works”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2011, and conflicting national standards shall be withdrawn at the latest by March 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 1536:1999. The general scope of TC 288 is the standardisation of the execution procedures for geotechnical works (including testing and control methods) and of the required material properties. WG15 has been charged to revise EN 1536:1999, with the subject area of bored piles, including barrettes, but not "micro piles" of diameter less than 0,3 m. The design, planning and execution of bored piles call for experience and knowledge in this specialised field. The execution phase requires skilled and qualified personnel and the present standard cannot replace the expertise of specialist contractor. The document has been prepared to complement EN 1997-1, Eurocode 7: Geotechnical design
Part 1: General rules and EN 1997-2, Eurocode 7
Geotechnical design
Part 2: Ground investigation and testing. Clause 7 "Considerations related to design" of this European Standard expands on design only where necessary (e.g. the detailing of reinforcement), but provides full coverage of the construction and supervision requirements. This standard contains additional requirements on concrete complementing the respective provisions of EN 206-1 and of EN 13670. The three standards are not yet fully accorded. It is anticipated that during future revisions several provisions now contained in EN 1536:2010, e.g. in 6.1, 6.3, 8.3 and 8.4 could be transferred to EN 206-1 and EN 13670. The document has been revised by a working group comprising delegates from eleven European countries and the comments from ten European countries have been received and taken into account. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.
NOTE 1 This standard covers piles or barrettes which are formed in the ground by excavation and are structural members used to transfer actions and/or limit deformations.
NOTE 2 This standard covers piles with circular cross-section (see Figures 1 and A.1a)) and barrettes (see 3.3) with rectangular, T or L or any other similar cross-section (see Figure 2) concreted in a single operation.
NOTE 3 In the standard the term pile is used for circular cross-section structure and the term barrette for other shapes. Both are bored piles.
Key Key D Shaft diameter L Barrette length
W Barrette thickness
A Cross-sectional area of the shaft Figure 1 — Bored pile with circular cross-section
Figure 2 — Bored pile with non circular cross-section (barrettes)
1.2
This European Standard applies to bored piles (see Figure 3) with:  uniform cross-section (straight shaft);  telescopically changing shaft dimensions;
 excavated base enlargements; or  excavated shaft enlargements. NOTE
The shape of a pile base and of an enlargement depends on the tool used for the excavation. SIST EN 1536:2011

Key Key
D
Shaft diameter n
Rake
DB Base enlargement diameter
DE Shaft enlargement diameter
Figure 3 — Examples for straight shaft piles and piles with shaft and base enlargement Figure 4 — Definition of the rake1.3
This European Standard applies (see Note) to:
 bored piles with a depth to width ratio ≥ 5;  piles (see Figures 1 and 3) with a shaft diameter 0,3 m ≤ D ≤ 3,0 m;  barrettes (see Figure 2) with the least dimension Wi ≥ 0,4 m, a ratio LBiB / Wi between its largest and its least dimensions ≤ 6 and a cross-sectional area A ≤ 15 m²;  piles with circular precast elements used as structural member (see Figure 7) with a least dimension DP ≥ 0,3 m;  barrettes with rectangular precast elements used as structural member with a least dimension WP ≥ 0,3 m.
NOTE The standard covers a large range of diameters. For small diameter bored piles less than 450 mm, the general specification can be adapted to cater for the lack of space (e.g. minimum bars number and spacing). 1.4
This European Standard applies to piles with the following rake (see Figure 4):  n ≥ 4 (Θ ≥ 76°);  n ≥ 3 (Θ ≥ 72°) for permanently cased piles.
1.5 This European Standard applies to bored piles with the following dimensions of the shaft or base enlargements (see Figure 3): a) base enlargements: 1) in non-cohesive ground: DB / D ≤ 2; 2) in cohesive ground: DB / D ≤ 3; b) shaft enlargements in any ground: DE / D ≤ 2; SIST EN 1536:2011

The provisions of this European Standard apply to:  single bored piles;  bored pile groups (see Figure 5);  walls formed by piles (see Figure 6).
Key D Shaft diameter ai
Centre to centre spacing of the piles Figure 5 — Examples of pile groups SIST EN 1536:2011

a < D p primary piles s secondary piles a) Secant pile wall
a ≅ D b) Contiguous pile wall
a > D c) Widely spaced pile wall
Key a
Centre to centre spacing of the piles
D
Shaft diameter
Lagging Figure 6 — Examples of pile walls 1.7
The bored piles which are the subject of this European Standard can be excavated by continuous or discontinuous methods using support methods for stabilizing the excavation walls where required. 1.8
This European Standard applies only to construction methods that allow the designed cross-sections to be produced. 1.9
The provisions apply to bored piles (see Figure 7) constructed of:  unreinforced (plain) concrete;  reinforced concrete;  concrete reinforced by means of special reinforcement such as steel tubes, steel sections or steel fibres;  precast concrete (including prestressed concrete) elements or steel tubes where the annular gap between the element or tube and the ground is filled by concrete, cement or cement-bentonite grout. SIST EN 1536:2011

a) Use of plain concrete b) Use of concrete with bar reinforcement c) Use of special reinforcement
(steel section or tube)
d) Use of precast concrete element as main or supplementary structural membere) Use of steel tube as main or supplementary structural member Key 1
Precast concrete element 2
Grout 3
Temporary casing (extracted) 4
Uncased excavation 5
Unreinforced or reinforced concrete or cement grout D
Shaft diameter Figure 7 — Examples of bored piles with circular cross-section 1.10
Micropiles, mixed-in-place columns, columns constructed by jet grouting, ground improvement for piling, mixed-in-place pile bases and diaphragm walls are not covered by this European Standard. SIST EN 1536:2011

10 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 197-1:2000, Cement
Part 1: Composition, specifications and conformity criteria for common cements EN 206-1:2000, Concrete — Part 1: Specification, performance, production and conformity EN 791, Drill rigs
Safety EN 934-2, Admixtures for concrete, mortar and grout — Part 2: Concrete admixtures
Definitions, requirements, conformity, marking and labelling EN 996, Piling equipment
Safety requirements
EN 1008, Mixing water for concrete
Specification for sampling, testing and assessing the suitability of water, including water recovered from processes in the concrete industry, as mixing water for concrete EN 1990, Eurocode
Basis of structural design
EN 1991 (all parts), Eurocode 1: Actions on structures EN 1992 (all parts), Eurocode 2: Design of concrete structures EN 1993 (all parts), Eurocode 3: Design of steel structures EN 1994 (all parts), Eurocode 4: Design of composite steel and concrete structures EN 1997-1, Eurocode 7: Geotechnical design
Part 1: General rules
EN 1997-2, Eurocode 7
Geotechnical design
Part 2: Ground investigation and testing EN 1998 (all parts), Eurocode 8: Design of structures for earthquake resistance EN 10025-2, Hot rolled products of structural steels
Part 2: Technical delivery conditions for non-alloy structural steels EN 10080, Steel for the reinforcement of concrete
Weldable reinforcing steel
General
EN 10210 (all parts), Hot finished structural hollow sections of non-alloy and fine grain steels
EN 10219 (all parts), Cold formed welded structural hollow sections of non-alloy and fine grain steels EN 10248 (all parts), Hot rolled sheet piling of non alloy steels
EN 10249 (all parts), Cold formed sheet piling of non alloy steels
EN 12620, Aggregates for concrete
EN 12794, Precast concrete products
Foundation piles EN 13670, Execution of concrete structures ISO/DIS 22477-1, Geotechnical investigation and testing
Testing of geotechnical structures
Part 1: Pile load test by static axially loaded compression SIST EN 1536:2011

NOTE 1 The following definitions are used for the construction of bored piles covered by this European Standard. Additional explanations of piling terms are listed in Annex A.
NOTE 2 In these definitions the term pile is used for circular cross-section structures and the term barrette for other shapes. Both are bored piles. 3.1
pile fr pieu de Pfahl slender structural member in the ground for the transfer of actions 3.2 bored pile fr pieu foré de Bohrpfahl pile or barrette formed with or without a pile casing by excavating or boring a hole in the ground and filling with plain or reinforced concrete 3.3 barrette fr barrette de Schlitzwandelement discrete length of diaphragm wall or a number of interconnecting lengths cast simultaneously (e.g. L-, T- or cruciform shapes) used to support vertical and/or lateral loads
3.4
continuous flight auger pile
CFA-pile fr pieu à la tarière continue creuse (CFA) de Schneckenbohrpfahl pile formed by means of a hollow stemmed continuous flight auger through the stem of which concrete or grout is pumped as the auger is extracted
NOTE See Figure A.4. 3.5
prepacked pile fr pieu ballasté injecté de Prepacked-Pfahl pile where the completed excavation is filled with coarse aggregate which is subsequently injected with grout from the bottom up 3.6
end bearing pile fr pieu travaillant en pointe de Spitzendruckpfahl bored pile transmitting actions to the ground mainly by compression on its base 3.7
friction pile fr pieu flottant de Reibungspfahl bored pile transmitting actions to the ground mainly by friction and adhesion between the lateral surface of the pile and the adjacent ground SIST EN 1536:2011

12 3.8
pile base grouting fr injection sous la base de Pfahlfußverpressung pressure injection of grout below the base of an installed bored pile base in order to enhance performance under load 3.9 pile shaft grouting fr injection au niveau du fût de Pfahlmantelverpressung injection of grout carried out after bored pile concrete has set for the enhancement of skin friction accomplished by the use of grouting pipes which are installed down the shaft, normally placed with the bored pile reinforcement 3.10 working pile fr pieu de fondation de Bauwerkspfahl bored pile for the foundation of a structure or as part of a bored pile wall 3.11
raking pile fr pieu incliné de Schrägpfahl pile installed at an inclination related to the horizontal
NOTE See Figure 4. 3.12
shaft diameter fr diamètre du fût de Pfahlschaftdurchmesser diameter of the part of the pile between the pile head and the pile base:  for piles constructed with casings: equal to the external diameter of the casing;  for piles constructed without a casing: equal to the maximum diameter of the boring tool 3.13
enlarged base fr base élargie de Fußaufweitung base of a bored pile formed to have an area greater than that of its shaft
NOTE For bored piles, normally constructed by the use of special underreaming or belling-out tools (see Figure 3). 3.14 casting level fr niveau de bétonnage de Betonierhöhe upper level to which concrete is cast in a bored pile excavation
NOTE It is above the cut-off level by a margin depending on the execution procedure. 3.15
cut-off level (trimming) fr niveau d'arase (recépage) de planmäßige Pfahlkopfhöhe; Kapphöhe prescribed level to which a bored pile is trimmed before connecting it to the substructure SIST EN 1536:2011

empty bore fr forage vide de Leerbohrung length of excavation from the working level to the cut-off level 3.17 temporary casing fr tubage de Verrohrung steel tube used to maintain stability of a pile excavation (e.g. in unstable ground) which is withdrawn during or after concrete placement 3.18 permanent casing fr tubage permanent de bleibende Verrohrung; dauerhafte Verrohrung steel tube used to maintain stability of a pile excavation (e.g. in unstable ground) which is not withdrawn but remains as permanent continuous surround NOTE It becomes part of the pile and may also act as a protective or load bearing unit. 3.19 lead-in tube fr virole
de Führungsrohr short temporary casing put in place to secure the side of the excavation against collapse at the bore top close to working platform level 3.20 liner
lining fr gaine, chemise de Hülse; Hülsenrohr tube, generally of thin steel plate, forming part of the pile shaft (e.g. used for the protection of pile shafts in soft grounds or to reduce negative skin friction) 3.21 support fluid fr fluide stabilisateur de Stützflüssigkeit fluid used during excavation to support bore hole walls and for flushing
NOTE It is usually a bentonite suspension or a polymer solution. 3.22 concreting pipe fr colonne de bétonnage de Betonierrohr, Schüttrohr metal pipe comprising several joined lengths, surmounted by a hopper or chute for concrete placement under dry conditions 3.23
tremie pipe fr tube plongeur de Kontraktorrohr concreting pipe, with watertight joints for submerged concrete placement SIST EN 1536:2011

14 3.24 integrity test fr essai d'intégrité de Integritätsprüfung test carried out on an installed bored pile for the verification of soundness of materials and of the pile geometry 3.25
sonic test fr essai d’auscultation sonique
de Ultraschallversuch integrity test where a series of sonic waves is passed between a transmitter and a receiver through the concrete of a bored pile and where the characteristics of the received waves are measured and used to infer the state of continuity and section variations of the bored pile shaft NOTE
There are several types of sonic tests which measure the velocity of the wave either along the pile length or between a transmitter and a receiver placed at the same level in the shaft. 3.26 coring test fr essai d'auscultation sonique par transparence de Prüfung mittels Kernbohrung integrity test carried out from core drillings in a bored pile shaft
3.27
test pile fr pieu d'essai de Probepfahl zur Ermittlung Tragfähigkeit; Probebelastungspfahl bored pile to which loads are applied to determine the resistance deformation characteristics of the bored pile and the surrounding ground NOTE Depending on the test performed, test pile can be working pile or expendable pile. 3.28
trial pile fr pieu de faisabilité de Probepfahl zur Prüfung Ausführbarkeit; Eignungspfahl bored pile installed to assess the practicability and suitability of the construction method for a particular application NOTE A trial pile can also be used as a test pile. 3.29
static pile load test fr essai de chargement statique de pieu de statische Probebelastung loading test where a bored pile is subjected to chosen static axial and/or lateral actions at the bored pile head for the analysis of its capacity 3.30 maintained pile load test ML-test fr essai de chargement de pieu par palier de lastgesteuerte Probebelastung static loading test in which a test pile has loads applied in incremental stages, each of which is held constant for a certain period or until pile motion has virtually ceased or has reached a prescribed limit SIST EN 1536:2011

3.32
dynamic pile load test fr essai de chargement dynamique de pieu de dynamischer Pfahlversuch loading test where a dynamic force is applied at the bored pile head for assessment of pile capacity 3.33
cutting ring fr trousse coupante de Bohrkrone; Schneidring bottom part of a casing, usually reinforced and with teeth to facilitate penetration into the ground 3.34
grout fr coulis de Mörtel; Injektionsgut, Verpressgut homogenous mixture of cement and water which may contain admixtures and additions
3.35
obstruction fr obstacle de Hindernis; Bohrhindernis natural (or man made) hard stratum, block or similar ground requiring special tools or methods for its excavation 3.36
skin (shaft) friction fr frottement latéral de Mantelreibung frictional and/or adhesive resistance on the bored pile surface 3.37
negative skin friction
downdrag fr frottement négatif de negative Mantelreibung frictional and/or adhesive action by which surrounding soil or fill transfers downward load to a bored pile when the soil or fill settles relative to the bored pile shaft 3.38
socket
fr ancrage de Felseinbindung; Pfahlfußeinbindung bottom part of a bored pile in hard ground (usually rock) 3.39
cover fr enrobage de Betonüberdeckung distance between the outside of the reinforcement cage and the nearest concrete surface
NOTE The nearest concrete surface considered is the nearest excavated face as formed by the excavation tool. SIST EN 1536:2011

16 3.40
execution specification
fr specifications d'exécution de Ausführungsunterlagen set of documents covering all drawings, technical data and requirements necessary for the execution of a particular project NOTE The execution specification is not one document but signifies the total sum of documents required for the execution of the work as provided by the designer to the constructor. It includes the project specification prepared to supplement and qualify the requirements of this European Standard, as well as referring the national provisions relevant in the place of use. 3.41
project specification
fr spécifications de l'ouvrage de Projektspezifikationen project specific document describing the requirements applicable for the particular project 4 Information needed for the execution of the work 4.1 General 4.1.1 Prior to the execution of the work, all necessary information shall be provided.
4.1.2
This information should include:  any legal or statutory restrictions;  the location of main grid lines for setting out;  the conditions of structures, roads, services, etc. adjacent to the work, including any necessary surveys;  a suitable quality management system, including supervision, monitoring and testing. 4.1.3 The information regarding the site conditions shall cover, where relevant:  the geometry of the site (boundary conditions, topography, access, slopes, headroom restrictions, etc.);  the existing underground structures, services, known contaminations, and archeological constraints;  the environmental restrictions, including noise, vibration, pollution;  the future or ongoing activities such as dewatering, tunnelling, deep excavations. 4.2 Special features 4.2.1 The special features shall cover, where relevant:  execution specifications (see 3.40);  previous use of the site;  adjacent foundations (types, loads and geometry);  geotechnical information and data as specified in Clause 5;  presence of obstructions in the ground (old masonry, anchors, etc.);
4.2.3 The survey shall be carried out and be available prior to the commencement of the works and its conclusions shall be used to define the threshold values for any movement which may affect adjacent structures by the works area constructions. 4.2.4 Any additional or deviating requirements falling within the permissions given in this standard shall be established and agreed before the commencement of the works and the quality control system shall be suitably amended. NOTE Such additional or deviating requirements can be: — reduced or increased geometrical construction deviations; — application of different or varying construction materials; — precast concrete elements; — special anchorage or doweling of bored piles to underlying rock; — special reinforcement such as the use of steel tubes or sections or of steel fibres; — grouting of bored pile shafts or bases; — cutting-off of bored pile heads with heavy equipment;
— extensive manual excavation. 5 Geotechnical investigation
5.1 General 5.1.1 The geotechnical investigation shall fulfil the requirements of EN 1997 (all parts). NOTE 1 The depth and the extent of the geotechnical investigation should be sufficient to identify all ground formations and layers affecting the construction, to determine the relevant properties of the ground and to recognize the ground SIST EN 1536:2011

18 conditions (e.g where end bearing is to be relied on, it should demonstrate that any competent founding stratum is not immediately underlain by a weaker stratum where there is a possibility of a punching failure or excessive movements).
NOTE 2 Relevant experience of the execution of comparable foundation works under similar conditions and/or in the vicinity of the site should be taken into account when determining the extent of site investigation (reference to relevant experience is permitted if appropriate means of verification are taken, e.g. by penetration, pressuremeter or other tests).
NOTE 3 Guidance is given in EN 1997-2 on the depth and the contents of investigations. 5.1.2 The geotechnical investigation report shall be available in time, to allow for reliable design and execution of the bored piles (e.g the choice of method of execution). 5.1.3
The sufficiency of the geotechnical investigation shall be checked for the design and execution of the bored piles. 5.1.4 If the geotechnical investigations are not sufficient, a supplementary investigation shall be conducted. 5.2 Specific requirements 5.2.1 Particular attention shall be paid to the following aspects, which are relevant to the execution of bored piles:  the ground level at any point of investigation or testing relative to the recognised national datum or to a fixed reference chart datum;  piezometric levels of all water-tables and permeability of the soils;  presence of coarse, highly permeable soils or cavities (natural or artificial), which can cause sudden losses of support fluid and instability of the bore during the excavation or can cause a sudden drop of concrete during the placement, and thus can require special measures;  presence, strength and deformation characteristics of soft soils, such as very soft clay or peat, which can cause difficulties during excavation or concreting (deformation or instability);  presence of boulders or obstructions which can cause difficulties during excavation and, an assessment of their size and frequency, when applicable;  presence, position, strength of hard rock or other hard materials which can cause difficulties during excavation and may require the use of special tools;  presence, extent and thickness of any strata that can be sensitive to water infiltration or to stress caused by piling tools (e.g. impact, percussion or vibration);  underground strata where high ground-water velocities exist;  detrimental chemistry of groundwater, soil and rock, and water temperatures if required;  detrimental chemistry of waste materials;  presence of pretreated soil, which can have an adverse effect during excavation;  mining beneath the site;
 site stability problems (slope stability for instance). 5.2.2 The piezometric levels of the various water-tables existing on the site shall be monitored separately and over a sufficient period of time to estimate the highest piezometric levels which can occur during construction of the piles.
NOTE The area to investigate depends on the function of the piles (foundation or retaining structure). 5.2.6 When bored pile walls are required to reach or penetrate into rock, the properties of the rock, including the degree of weathering and the extent and direction of fissuring shall be assessed. 6 Materials and products
6.1 Constituents
6.1.1 General 6.1.1.1 The constituents shall meet the requirements set in the respective European Standards, the provisions valid in the place of use and the provisions given in the project specification.
6.1.1.2
The sources of supply of constituents shall be documented and shall not be changed without prior notification. 6.1.2 Bentonite 6.1.2.1 A distinction should be made between calcium bentonite, natural sodium bentonite and activated bentonite, which is a sodium bentonite produced from natural calcium bentonite by ion exchange. NOTE 1 Bentonite is a clay containing mainly the mineral montmorillonite.
NOTE 2 Bentonite is used in support fluids, either as a pure bentonite suspension or as an addition to polymers solutions. It is also used as a constituent part of hardening slurries and of plastic concrete. 6.1.2.2 Bentonite used in bentonite suspensions shall not contain harmful constituents in such quantities as can be detrimental to reinforcement or concrete. 6.1.2.3 The chemical and mineralogical composition of the bentonite shall be supplied. 6.1.3 Polymers Polymers can be used as sole constituent in supporting fluids or as additives to enhance rheological effectiveness. NOTE 1 Polymers are materials formed of molecules from chained monomeric units.
NOTE 2
There are different types of polymers ranging from natural gums to specially tailored blends of synthetic products. 6.1.4 Cement 6.1.4.1 Cement for bored piles shall be of the following types as defined in EN 197-1:2000: SIST EN 1536:2011

20  Portland cement CEM I;  Portland-slag cement CEM II/A-S an
...