The European Guidelines
for
Self-Compacting Concrete Specification, Production and Use
May 2005
FOREWORD
These Guidelines and specifications were prepared by a project group comprising five European Federations dedicated to the promotion of advanced materials, and systems for the supply and use of concrete. The Self-Compacting Concrete European Project Group was founded in January 2004 with representatives from:
BIBM The European Precast Concrete Organisation.
CEMBUREAU The European Cement Association.
ERMCO The European Ready-mix Concrete Organisation.
EFCA The European Federation of Concrete Admixture Associations.
EFNARC The European Federation of Specialist Construction Chemicals and Concrete Systems.
All comments on “The European Guidelines for Self Compacting Concrete” should be submitted to the
EPG Secretary at:
https://www.doczj.com/doc/c89187665.html, or https://www.doczj.com/doc/c89187665.html,
ACKNOWLEDGEMENT
The European Project Group acknowledges the contribution made in drafting this document by a wide range of expertise from within the concrete and construction industry. The five EPG working groups
drew on the SCC experience of more than 50 people from 12 European countries and on collaboration
with the The UK Concrete Society and the EC “TESTING-SCC” project 2001-2004.
Diagrams and photographs provided by:
Betonson BV, NL Price and Myers Consulting Engineers
Degussa Lafarge
Doka Schalungstechnik GmbH Sika
Hanson The “TESTING-SCC” project
Bennenk Holcim W.
Although care has been taken to ensure, to the best of our knowledge that all data and information contained herein is accurate to
the extent that it relates to either matters of fact or accepted practice or matters of opinion at the time of publication, the SCC joint
project group assumes no responsibility for any errors in or misrepresentation of such data and/or information or any loss or damage arising from or related to its use.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, recording or otherwise, without prior permission of the SCC European Project Group.
CONTENTS
1 1 Introduction
1
2 Scope
standards 3 3 Referenced
and
definitions 3
4 Terms
5 5 Engineering
properties
5.1 General
5.2 Compressive
strength
strength
5.3 Tensile
5.4 Static modulus of elasticity
5.5 Creep
5.6 Shrinkage
5.7 Coefficient of thermal expansion
5.8 Bond to reinforcement, prestressing and wires
5.9 Shear force capacity across pour planes
resistance
5.10 Fire
5.11 Durability
5.12 References
6 Specifying SCC for ready-mixed & site mixed concrete 10
6.1 General
6.2 Specification
6.3 Requirements in the fresh state
classification
6.4 Consistence
examples
6.5 Specification
materials 15 7 Constituent
7.1 General
7.2 Cement
7.3 Additions
7.4 Aggregates
7.5 Admixtures
7.6 Pigments
7.7 Fibres
water
7.8 Mixing
composition
19 8 Mix
8.1 General
8.2 Mix design principles
methods
8.3 Test
8.4 Basic mix design
8.5 Mix design approach
8.6 Robustness in the fresh state
9 Production for ready-mixed and site mixed SCC 24
9.1 General
9.2 Storage of constituent materials
9.3 Mixing equipment and trial mixes
9.4 Plant mixing procedures
control
9.5 Production
9.6 Transportation and delivery
9.7 Site
acceptance
and
preparation 28 Site
10
requirements
10.1 General
10.2 Site control
adjustment
10.3 Mix
skills
10.4 Supervision
and
pressure
10.5 Formwork
design
10.6 Formwork
preparation
10.7 Formwork
10.8 Formwork for pumping bottom up
finishing
site 32
on
11
Placing
and
11.1 General
11.2 Discharging
11.3 Placing procedure and rate
11.4 Placing by pump
11.5 Placing by concrete chute or skip
11.6 Vibration
slabs
11.7 Finishing
11.8 Curing
37
products
12
Precast
concrete
12.1 General
12.2 Specifying SCC for use in precast concrete products
12.3 Mix design of SCC for precast concrete products
12.4 Moulds
production
12.5 Factory
12.6 Placing
12.7 Finishing, curing and de-moulding
finish
surface
40
Appearance
and
13
13.1 General
13.2 Blowholes
13.3 Honeycombing
13.4 Colour consistency and surface aberrations
13.5 Minimising surface cracking
ANNEX
of
SCC 43 A Specification
A.1 Scope
A.2 Normative references
A.3 Definitions, symbols and abbreviations
A.4 Classification
A.5 Requirements for concrete and methods of verification
A.6 Delivery of fresh concrete
A.7 Conformity control and conformity criteria
control
A.8
Production
for
SCC 47 methods
B Test
B1: Slump-flow and T500 time
test
B2:
V-funnel
test
L-box
B3:
B4: Sieve segregation resistance test
of
SCC 60
the
C Improving
finish
1 Introduction
Self-compacting concrete (SCC) is an innovative concrete that does not require vibration for placing and compaction. It is able to flow under its own weight, completely filling formwork and achieving full compaction, even in the presence of congested reinforcement. The hardened concrete is dense, homogeneous and has the same engineering properties and durability as traditional vibrated concrete.
Concrete that requires little vibration or compaction has been used in Europe since the early 1970s
but self-compacting concrete was not developed until the late 1980’s in Japan. In Europe it was probably first used in civil works for transportation networks in Sweden in the mid1990’s. The EC funded a multi-national, industry lead project “SCC” 1997-2000 and since then SCC has found increasing use in all European countries.
Self-compacting concrete offers a rapid rate of concrete placement, with faster construction times and ease of flow around congested reinforcement. The fluidity and segregation resistance of SCC ensures a high level of homogeneity, minimal concrete voids and uniform concrete strength, providing the potential for a superior level of finish and durability to the structure. SCC is often produced with low water-cement ratio providing the potential for high early strength, earlier demoulding and faster use of elements and structures.
The elimination of vibrating equipment improves the environment on and near construction and precast sites where concrete is being placed, reducing the exposure of workers to noise and vibration.
The improved construction practice and performance, combined with the health and safety benefits, make SCC a very attractive solution for both precast concrete and civil engineering construction.
In 2002 EFNARC published their “Specification & Guidelines for Self-Compacting concrete” which, at that time, provided state of the art information for producers and users. Since then, much additional technical information on SCC has been published but European design, product and construction standards do not yet specifically refer to SCC and for site applications this has limited its wider acceptance, especially by specifiers and purchasers.
In 1994 five European organisations BIBM, CEMBUREAU, ERMCO, EFCA and EFNARC, all dedicated to the promotion of advanced materials and systems for the supply and use of concrete, created a “European Project Group” to review current best practice and produce a new document covering all aspects of SCC. This document “The European Guidelines for Self Compacting Concrete”serves to particularly address those issues related to the absence of European specifications, standards and agreed test methods.
2 Scope
“The European Guidelines for Self Compacting Concrete” represent a state of the art document addressed to those specifiers, designers, purchasers, producers and users who wish to enhance their expertise and use of SCC. The Guidelines have been prepared using the wide range of the experience and knowledge available to the European Project Group. The proposed specifications and related test methods for ready-mixed and site mixed concrete, are presented in a pre-normative format, intend to facilitate standardisation at European level. This approach should encourage increased acceptance and utilisation of SCC.
“The European Guidelines for Self Compacting Concrete” define SCC and many of the technical terms used to describe its properties and use. They also provide information on standards related to testing and to associated constituent materials used in the production of SCC.
Durability and other engineering properties of hardened concrete are covered to provide reassurance to designers on compliance of SCC with EN 1992-1-1 Design of concrete structures (Eurocode 2)
The Guideline cover information that is common to SCC for the ready-mixed, site mixed and the precast concrete industry. Chapter 12 is devoted to the specific requirements of precast concrete products.
The Guidelines are drafted with an emphasis on ready-mixed and site mixed concrete where there are requirements between the purchaser and supplier in relation to the specification of the concrete in both the fresh and hardened state. In addition, the Guidelines cover specific and important requirements for the purchaser of SCC regarding the site preparation and methods of placing where these are different to traditional vibrated concrete.
The specification of precast concrete is usually based on the quality of the final concrete product in its hardened state according to the requirements of the relevant product standards and on EN 13369: Common rules for precast concrete products. EN 13369 refers only to the parts of EN 206-1 that concern the requirements for the concrete in the hardened state. The requirements for the concrete in the fresh state will be defined by the manufacturers own internal specification.
The document describes the properties of SCC in its fresh and hardened state, and gives advice to the purchaser of ready-mixed and site mixed concrete on how SCC should be specified in relation to the current European standard for structural concrete, EN 206-1. It also describes the test methods used to support this specification. The appended specification and test methods are presented in a pre-normative format that mirrors current EN concrete standards.
Advice is given to the producer on constituent materials, their control and interaction. Because there are a number of different approaches to the design of SCC mixes, no specific method is recommended, but a comprehensive list of papers describing different methods of mix design is provided.
Advice is given to the contractor/user of ready-mixed and site mixed concrete on delivery and placing. Whilst accepting that SCC is a product used by both the precast and in-situ industries, the Guidelines attempt to give specific advice related to the differing requirements of the two sectors. For example, early setting and early strength are important to precasters, whereas workability retention may be more important in in-situ applications.
standards
3 Referenced
EN 197-1 Cement – Part 1: Composition, specifications and conformity criteria for common cements EN 206-1 Concrete – Part 1: Specification, performance, production, and conformity
EN 450-1 Fly ash for concrete – Part 1: Definitions, specifications and quality control
EN 450-2 Fly ash for concrete – Part 2: Conformity control
EN 934-2 Admixtures for concrete, mortar and grout – Part 2: Concrete admixtures - Definitions and 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
EN1992-1 Eurocode 2: Design of concrete structures Part 1-1 – General rules and rules for buildings
Part 1-2 – General rules – Structural file design EN 12350-1 Testing fresh concrete: Part 1: Sampling
EN 12350-2 Testing fresh concrete: Part 2: Slump test
EN 12620 Aggregates for concrete
EN 12878 Pigments for colouring of building materials based on cement and/or lime – Specification and methods of test
EN 13055-1 Lightweight aggregates – Part 1: Lightweight aggregates for concrete, mortar and grout EN 13263-1 Silica fume for concrete – Part 1: Definitions, requirements and conformity control
EN 13263-2 Silica fume for concrete – Part 2: Conformity evaluation
EN 13369 Common rules for precast concrete products
EN 13670 Execution of concrete structures
EN 14889 Fibres for concrete
EN 15167-1 Ground granulated blastfurnace slag for use in concrete, mortar and grout – Part 1: Definitions, specifications and conformity criterion
EN 15167 -2 Ground granulated blastfurnace slag for use in concrete, mortar and grout – Part 2: Conformity evaluation
EN ISO 5725 Accuracy (trueness and precision) of Measurement Methods and Results
EN ISO 9001 Quality management systems – Requirements
Note: Some of these EN standards are still in preparation; the latest version of undated standards should be referred to.
4 Terms and definitions
For the purposes of this publication, the following definitions apply:
Addition
Finely-divided inorganic material used in concrete in order to improve certain properties or to achieve special properties. This publication refers to two types of inorganic additions defined in EN 206-1 as: nearly inert additions (Type l); pozzolanic or latent hydraulic additions (Type ll)
Admixture
Material added during the mixing process of concrete in small quantities related to the mass of cementitous binder to modify the properties of fresh or hardened concrete
Binder
The combined cement and Type ll addition
Filling ability
The ability of fresh concrete to flow into and fill all spaces within the formwork, under its own weight
Fines
See Powder
Flowability
The ease of flow of fresh concrete when unconfined by formwork and/or reinforcement
Fluidity
The ease of flow of fresh concrete
Mortar
The fraction of the concrete comprising paste plus those aggregates less than 4 mm
Paste
The fraction of the concrete comprising powder, water and air, plus admixture, if applicable
Passing ability
The ability of fresh concrete to flow through tight openings such as spaces between steel reinforcing bars without segregation or blocking
Powder (Fines)
Material of particle size smaller than 0.125 mm
NOTE: It includes this size fraction in the cement, additions and aggregate
Proprietary concrete
Concrete for which the producer assures the performance subject to good practice in placing, compacting and curing, and for which the producer is not required to declare the composition
Robustness
The capacity of concrete to retain its fresh properties when small variations in the properties or quantities of the constituent materials occur
Self-compacting concrete (SCC)
Concrete that is able to flow and consolidate under its own weight, completely fill the formwork even in the presence of dense reinforcement, whilst maintaining homogeneity and without the need for any additional compaction
Segregation resistance
The ability of concrete to remain homogeneous in composition while in its fresh state
Slump-flow
The mean diameter of the spread of fresh concrete using a conventional slump cone
Thixotropy
The tendency of a material (e.g. SCC) to progressive loss of fluidity when allowed to rest undisturbed but to regain its fluidity when energy is applied
Viscosity
The resistance to flow of a material (e.g. SCC) once flow has started.
NOTE: In SCC it can be related to the speed of flow T500 in the Slump-flow test or the efflux time in the V-funnel test
Viscosity Modifying Admixture (VMA)
Admixture added to fresh concrete to increase cohesion and segregation resistance.
5 Engineering
properties
5.1 General
Self-compacting concrete and traditional vibrated concrete of similar compressive strength have comparable properties and if there are differences, these are usually covered by the safe assumptions on which the design codes are based. However, SCC composition does differ from that of traditional concrete so information on any small differences that may be observed is presented in the following sections. Whenever possible, reference is made to EN1992-1 and EN206-1:2000 [1] [2].
Durability, the capability of a concrete structure to withstand environmental aggressive situations during its design working life without impairing the required performance, is usually taken into account by specifying environmental classes. This leads to limiting values of concrete composition and minimum concrete covers to reinforcement.
In the design of concrete structures, engineers may refer to a number of concrete properties, which are not always part of the concrete specification. The most relevant are:
Compressive strength
Tensile strength
Modulus of elasticity
Creep
Shrinkage
Coefficient of thermal expansion
Bond to reinforcement
Shear force capacity in cold joints
Fire resistance
Where the value and/or the development of a specific concrete property with time is critical, tests should be carried out taking into account the exposure conditions and the dimensions of the structural member.
strength
5.2 Compressive
Self-compacting concrete with a similar water cement or cement binder ratio will usually have a slightly higher strength compared with traditional vibrated concrete, due to the lack of vibration giving an improved interface between the aggregate and hardened paste. The strength development will be similar so maturity testing will be an effective way to control the strength development whether accelerated heating is used or not.
A number of concrete properties may be related to the concrete compressive strength, the only concrete engineering property that is routinely specified and tested.
strength
5.3 Tensile
Self-compacting concrete may be supplied with any specified compressive strength class. For a given concrete strength class and maturity, the tensile strength may be safely assumed to be the same as the one for a normal concrete as the volume of paste (cement + fines + water) has no significant effect on tensile strength.
In the design of reinforced concrete sections, the bending tensile strength of the concrete is used for the evaluation of the cracking moment in prestressed elements, for the design of reinforcement to control crack width and spacing resulting from restrained early-age thermal contraction, for drawing moment-curvature diagrams, for the design of unreinforced concrete pavements and for fibre reinforced concrete.
In prestressed units the splitting tensile stresses around the strands as well as their rate of drawn-in (slippage) in the end section when releasing the prestressing forces are related to f`ct, the compressive strength at release. Cracks due to splitting tensile stresses should generally be avoided.
5.4 Static modulus of elasticity
The modulus of elasticity (E-value, the ratio between stress and strain), is used in the elastic calculation of deflection, often the controlling parameter in slab design, and of pre or post tensioned elements.
As the bulk of the volume of concrete is aggregate, the type and amount of aggregate as well as its E-value have the most influence. Selecting an aggregate with a high E-value will increase the modulus of elasticity of concrete. However, increasing the paste volume could decrease the E-value. Because SCC often has a higher paste content than traditional vibrated concrete, some differences can be expected and the E-value may be somewhat lower but this should be adequately covered by the safe assumptions on which the formulae provided in EN1992-1-1 are based.
If SCC does have a slightly lower E modulus than traditional vibrated concrete, this will affect the relationship between the compressive strength and the camber due to prestressing or post-tensioning. For this reason, careful control should be exercised over the strength at the time when the prestressing and post-tensioning strands or wires are released.
5.5 Creep
Creep is defined as the gradual increase in deformation (strain) with time for a constant applied stress, also taking into account other time dependent deformations not associated with the applied stress, i.e. shrinkage, swelling and thermal deformation.
Creep in compression reduces the prestressing forces in prestressed concrete elements and causes a slow transfer of load from the concrete onto the reinforcement. Creep in tension can be beneficial in that it in part relieves the stresses induced by other restrained movements, e.g. drying shrinkage and thermal effects.
Creep takes place in the cement paste and it is influenced by its porosity which is directly related to its water/cement ratio. During hydration, the porosity of the cement paste reduces and so for a given concrete, creep reduces as the strength increases. The type of cement is important if the age of loading is fixed. Cements that hydrate more rapidly will have higher strength at the age of loading, a lower stress/strength ratio and a lower creep. As the aggregates restrain the creep of the cement paste, the higher the volume of the aggregate and the higher the E-value of the aggregate, the lower the creep will be.
Due to the higher volume of cement paste, the creep coefficient for SCC may be expected to be higher than for normal concrete of equal strength, but such differences are small and covered by the safe assumptions in the tables and the formulae provided in the Eurocode.
5.6 Shrinkage
Shrinkage is the sum of the autogenous and the drying shrinkage. Autogenous shrinkage occurs during setting and is caused by the internal consumption of water during hydration. The volume of the hydration products is less than the original volume of unhydrated cement and water and this reduction in volume causes tensile stresses and results in autogenous shrinkage.
Drying shrinkage is caused by the loss of water from the concrete to the atmosphere. Generally this loss of water is from the cement paste, but with a few types of aggregate the main loss of water is from the aggregate. Drying shrinkage is relatively slow and the stresses it induces are partially balanced by tension creep relief.
The aggregate restrains the shrinkage of the cement paste and so the higher the volume of the aggregate and the higher the E-value of the aggregate, the lower the drying shrinkage. A decrease in the maximum aggregate size which results in a higher paste volume increases the drying shrinkage.
The values and formulae given in the Eurocode for normal concrete are still valid in the case of SCC.
As concrete compressive strength is related to the water cement ratio, in SCC with a low water/cement ratio drying shrinkage reduces and the autogenous shrinkage can exceed it.
Tests performed on creep and shrinkage of different types of SCC and a reference concrete [7] show that ?the deformation caused by shrinkage may be higher
?the deformation caused by creep may be lower
?the value for the sum of the deformations due to shrinkage and creep are almost similar
Due to the restrain of the presence of reinforcement in a cross section the shrinkage strain will cause tension in concrete and compression in the reinforcement.
5.7 Coefficient of thermal expansion
The coefficient of thermal expansion of concrete is the strain produced in concrete after a unit change in temperature where the concrete is not restrained either internally (by reinforcing bars) or externally.
The coefficient of thermal expansion of concrete varies with its composition, age and moisture content. As the bulk of concrete comprises aggregate, using an aggregate with a lower coefficient of thermal expansion will reduce the coefficient of thermal expansion of the resulting concrete. Reducing the coefficient of thermal expansion leads to a proportional reduction in the crack control reinforcement.
While the range of the coefficient of thermal expansion is from 8 to13 microstrains/K, EN 1992-1-1 states that unless more accurate information is available, it may be taken as 10 to 13 microstrains/K. The same may be assumed in the case of SCC.
5.8 Bond to reinforcement, prestressing and wires
Reinforced concrete is based on an effective bond between concrete and the reinforcing bars. The concrete bond strength should be sufficient to prevent bond failure. The effectiveness of bond is affected by the position of the embedded bars and the quality of concrete as cast. An adequate concrete cover is necessary in order to properly transfer bond stresses between steel and concrete.
Poor bond often results from a failure of the concrete to fully encapsulate the bar during placing or bleed and segregation of the concrete before hardening which reduce the quality of contact on the bottom surface. SCC fluidity and cohesion minimise these negative effects, especially for top bars in deep sections [5].
In the case of strands the transfer and anchorage length in different types of SCC have been compared with the performance in vibrated concrete of the same compressive stress. The transfer length for strands embedded in SCC was shown to be on the safe side when compared with the calculated values according the EN1992-1 and EN206-1 see also [7] [8].
Even if bond properties are generally enhanced when SCC is used, for a given compressive strength the formulae used in the Code should be used.
5.9 Shear force capacity across pour planes
The surface of hardened SCC after casting and hardening may be rather smooth and impermeable. Without any treatment of the surface after placing the first layer, the shear force capacity between the first and second layer may be lower than for vibrated concrete and may therefore be insufficient to carry any
shear force. A surface treatment such as surface retarders, brushing or surface roughening should to be sufficient, [7] [9].
resistance
5.10 Fire
Concrete is non-combustible and does not support the spread of flames. It produces no smoke, toxic gases or emissions when exposed to fire and does not contribute to the fire load. Concrete has a slow rate of heat transfer which makes it an effective fire shield for adjacent compartments and under typical fire conditions, concrete retains most of its strength. The European Commission has given concrete the highest possible fire designation, A1.
The fire resistance of SCC is similar to normal concrete [7] In general a low permeability concrete may be more prone to spalling but the severity depends upon the aggregate type, concrete quality and moisture content [6]. SCC can easily achieve the requirements for high strength, low permeability concrete and will perform in a similar way to any normal high strength concrete under fire conditions [7].
The use of polypropylene fibres in concrete has been shown to be effective in improving its resistance to spalling. The mechanism is believed to be due to the fibres melting and being absorbed in the cement matrix. The fibre voids then provide expansion chambers for steam, thus reducing the risk of spalling. Polypropylene fibres have been successfully used with SCC.
5.11 Durability
The durability of a concrete structure is closely associated to the permeability of the surface layer, the one that should limit the ingress of substances that can initiate or propagate possible deleterious actions (CO2, chloride, sulphate, water, oxygen, alkalis, acids, etc.). In practice, durability depends on the material selection, concrete composition, as well as on the degree of supervision during placing, compaction, finishing and curing.
Lack of compaction of the surface layer, due to vibration difficulties in narrow spaces between the formwork and the re-bars or other inserts (e.g. post-tensioning ducts) has been recognised as a key factor of poor durability performance of reinforced concrete structures exposed to aggressive environments. Overcoming this was one of the main reasons for the original development of SCC in Japan.
Traditional vibrated concrete is subjected to compaction via vibration (or tamping), which is a discontinuous process. In the case of internal vibration, even when correctly executed, the volume of concrete within the area of influence of the vibrator does not receive the same compaction energy. Similarly, in the case of external vibration, the resulting compaction is essentially heterogeneous, depending on the distance to the vibration sources.
The result of the vibration is, therefore, a concrete in the structure with uneven compaction and, therefore, with different permeabilities, which enhances the selective ingress of aggressive substances. Naturally, the consequences of incorrect vibration (honeycombing, segregation, bleeding, etc.) have a much stronger negative effect on permeability and, hence, on durability.
Self-compacting concrete with the right properties will be free from those shortcomings and result in a material of consistently low and uniform permeability, offering less weak points for deleterious actions of the environment and, hence, better durability. The comparison of permeability between SCC and normal vibrated concrete will depend on the selection of materials and the effective water cement or water binder ratio.
There are test methods, either standardised nationally or recommended by RILEM to measure the permeability of concrete, in the laboratory and in-situ, as durability indicators. EN1992-1 and EN206 -1 both take into account durability by specifying environmental classes leading to limiting values of concrete composition and to minimum concrete cover to reinforcement [1] [2].
5.12 References
[1] EN1992-1 – Eurocode 2:Design of concrete structures Part 1 –1 – General rules and rules for
buildings -Part 1-2 – General rules – Structural file design
[2] EN206-1: 2000 - Concrete Part 1 – Specification, performance, production and conformity
[3] BROOKS, J Elasticity, shrinkage, creep and thermal movement. Advanced Concrete Technology –
Concrete properties, Edited by John Newman and Ban Seng Choo, ISBN 0 7506 5104 0, 2003.
[4] HARRISON, T A Early-age thermal crack control in concrete. CIRIA Report 91, Revised edition 1992
ISBN 0 86017 329 1
[5] SONEBI, M, WENZHONG,Z and GIBBS, J Bond of reinforcement in self-compacting concrete –
CONCRETE July-August 2001
[6] CATHER, R Concrete and fire exposure. Advanced Concrete Technology – Concrete properties,
Edited by John Newman and Ban Seng Choo, ISBN 0 7506 5104 0, 2003.
[7] DEN UIJL, J.A., Zelfverdichtend Beton, CUR Rapport 2002-4 -Onderzoek in opdracht van CUR
Commissie B79 Zelfverdichtend Beton, Stichting CUR, ISBN 90 3760 242 8.
[8] VAN KEULEN, D, C, Onderzoek naar eigenschappen van Zelfverdichtend Beton, Rapport
TUE/BCO/00.07, April 2000.
[9] JANMAAT, D, WELZEN.M.J.P, Schuifkrachtoverdracht in schuifvlakken van zelfverdichtend beton bij
prefab elementen, Master Thesis, Rapport TUE/CCO/A-2004-6.
Figure 5.1: Surface detail on precast element with SCC filling under the formwork.
6 Specifying SCC for ready-mixed and site mixed concrete
6.1 General
The specification, performance and conformity requirements for structural concrete are given in EN 206-1. However, in the case of SCC some properties in the fresh state exceed the limits and classes provided in this standard. None of the test methods in the current EN 12350 series ‘Testing fresh concrete’ are suitable for assessment of the key properties of fresh SCC. Appropriate test methods for SCC are given in Annex B of these Guidelines and it is envisaged that the EN 12350 series will be extended to cover these test methods.
The filling ability and stability of self-compacting concrete in the fresh state can be defined by four key characteristics. Each characteristic can be addressed by one or more test methods:
Characteristic Preferred test method(s)
Flowability Slump-flow test
Viscosity (assessed by rate of flow) T500 Slump-flow test or V-funnel test
Passing ability L-box test
Segregation Segregation resistance (sieve) test
These test methods for SCC are described in Annex B.
Full details for the specification, performance, production and conformity of SCC, where these complement EN 206-1, are described in Annex A.
Further advice on specification of SCC in the fresh state is given in Clauses 6.3 and 6.4.
6.2 Specification
SCC will normally be specified as a prescribed or proprietary concrete.
The prescribed concrete method is most suitable where the specifier and producer/user are the same party, e.g. in site mixed.
For commercial reasons the ready-mixed concrete producer will probably prefer the proprietary method of specification (see annex A), following consultation between the purchaser and the producer. The proprietary method focuses on the performance of the concrete and places responsibility on the producer to achieve this performance. It is not usually practical for the specifier to develop their own SCC and then specify the mix proportions to the producer and if they do follow this route, they cannot also specify a strength class.
The specification for self-compacting concrete using the proprietary concrete method shall contain:
a) basic requirements given in Sub-clause 6.2.1 of these Guidelines
b) additional requirements given in Sub-clause 6.2.2 where required
6.2.1 Basic requirements
The specification for self-compacting concrete shall contain:
a) requirement to conform to ‘The European Guidelines for SCC, May 2005,Annex A’ ;
b) compressive strength class (see Note 1 and EN 206-1: 2000, 4.3.1);
c) exposure class(s) and/or limiting values of composition, e.g. maximum w/c ratio, minimum
cement content (see provision valid in the place of use);
d) maximum nominal upper aggregate size;
e) chloride class (see EN 206-1: 2000, 5.2.7);
f) slump-flow class or, in special cases,a target value (see Annex A, Table A.6).
NOTE 1: In some EU Member States only specific strength classes are applied according to National Application Documents (NAD)
NOTE 2: Consideration should be given to specifying a requirement for the producer to operate an accredited quality system meeting the requirements of EN ISO 9001.
6.2.2 Additional requirements
In addition to the basic requirements (Sub-clause 6.2.1), the specification for self-compacting concrete shall contain any of the following additional requirements and provisions that are deemed to be necessary, specifying performance requirements and test methods as appropriate:
a) T500 value for the slump-flow test (see Annex A, Table A.2) or a V-funnel class (see Annex A,
Table A.3);
b) L-box class or, in special cases, a target value (see Annex A, Table A.4);
c) Segregation resistance class or, in special cases, a target value (see Annex A, Table A.5);
d) Requirements for the temperature of the fresh concrete, where different from those in EN 206-1:
2000, 5.2.8;
e) Other technical requirements.
NOTE 1. Where these tests are required routinely, the rate of testing shall be specified.
6.3 Requirements in the fresh state
Specific requirements for SCC in the fresh state depend on the type of application, and especially on: ?confinement conditions related to the concrete element geometry, and the quantity, type and location of reinforcement, inserts, cover and recesses etc.
?placing equipment (e.g. pump, direct from truck-mixer, skip, tremie)
?placing methods (e.g. number and position of delivery points)
? finishing method
The classifying system detailed in Annex A allows for an appropriate specification of SCC to cover these requirements, which are characterised as:
SF 3
classes ?Flowability Slump-flow
?Viscosity, (measure of the speed of flow) Viscosity VS or VF 2 classes
?Passing ability, (flow without blocking) Passing ability PA 2 classes
resistance
Segregation resistance SR 2 classes ?Segregation
Details of the test methods for these characteristics can be found in Annex B.
Information on selection of parameters and classes is given in Clause 6.4.
Self-compacting concrete requirements in the fresh state that are appropriate for a given application should be selected from one or more of these four key characteristics and then specified by class or target value according to Annex A.
For ready-mixed or site mixed concrete, characteristics and classes should be carefully selected, controlled and justified on the basis of contractor and concrete producer experience or by specific trials. It is therefore important that the concrete purchaser and concrete producer discuss and define clearly those characteristics before starting the project.
The concrete purchaser should only select those fresh concrete characteristics necessary for the particular SCC application and over specification of both the concrete characteristic and class should be avoided. Slump-flow will normally be specified for all SCC.
Passing ability, viscosity and segregation resistance will affect the in-situ properties of the hardened concrete but should only be specified if specifically needed.
?If there is little or no reinforcement, there may be no need to specify passing ability as a requirement.
?Viscosity may be important where good surface finish is required or reinforcement is very congested but should not be specified in most other cases.
?Segregation resistance becomes increasingly important with higher fluidity and lower viscosity SCC but if it needs to be specified, class 1 has been shown to be adequate for most applications.
See Clause 6.4 for additional advice on specifying.
The required consistence retention time will depend on the transportation and placing time. This should be determined and specified and it is the responsibility of the producer to ensure that the SCC maintains its specified fresh properties during this period.
Self-compacting concrete should, if possible be placed in one continuous pour so delivery rates should be matched to placing rate and also be agreed with the producer in order to avoid placing stoppages due to lack of concrete or long delays in placing after the concrete reaches site.
6.4 Consistence
classification
6.4.1 Slump-flow
Slump-flow value describes the flowability of a fresh mix in unconfined conditions. It is a sensitive test that will normally be specified for all SCC, as the primary check that the fresh concrete consistence meets the specification. Visual observations during the test and/or measurement of the T500 time can give additional information on the segregation resistance and uniformity of each delivery.
The following are typical slump-flow classes for a range of applications:
SF1 (550 - 650 mm) is appropriate for:
?unreinforced or slightly reinforced concrete structures that are cast from the top with free displacement from the delivery point (e.g. housing slabs)
?casting by a pump injection system (e.g. tunnel linings)
?sections that are small enough to prevent long horizontal flow (e.g. piles and some deep foundations).
SF2 (660 - 750 mm) is suitable for many normal applications (e.g. walls, columns)
SF3 (760 – 850 mm) is typically produced with a small maximum size of aggregates (less than 16 mm) and is used for vertical applications in very congested structures, structures with complex shapes, or for filling under formwork. SF3 will often give better surface finish than SF 2 for normal vertical applications but segregation resistance is more difficult to control.
Target values higher than 850 mm may be specified in some special cases but great care should be taken regarding segregation and the maximum size of aggregate should normally be lower than 12 mm.
6.4.2 Viscosity
Viscosity can be assessed by the T500 time during the slump-flow test or assessed by the V-funnel flow time. The time value obtained does not measure the viscosity of SCC but is related to it by describing the rate of flow. Concrete with a low viscosity will have a very quick initial flow and then stop. Concrete with a high viscosity may continue to creep forward over an extended time.
Viscosity (low or high) should be specified only in special cases such as those given below. It can be useful during mix development and it may be helpful to measure and record the T500 time while doing the slump-flow test as a way of confirming uniformity of the SCC from batch to batch.
VS1/VF1 has good filling ability even with congested reinforcement. It is capable of self-levelling and generally has the best surface finish. However, it is more likely to suffer from bleeding and segregation.
VS2/VF2 has no upper class limit but with increasing flow time it is more likely to exhibit thixotropic effects, which may be helpful in limiting the formwork pressure (see Clause 10.5) or improving segregation resistance. Negative effects may be experienced regarding surface finish (blow holes) and sensitivity to stoppages or delays between successive lifts.
ability
6.4.3 Passing
Passing ability describes the capacity of the fresh mix to flow through confined spaces and narrow openings such as areas of congested reinforcement without segregation, loss of uniformity or causing blocking. In defining the passing ability, it is necessary to consider the geometry and density of the reinforcement, the flowability/filling ability and the maximum aggregate size.
The defining dimension is the smallest gap (confinement gap) through which SCC has to continuously flow to fill the formwork. This gap is usually but not always related to the reinforcement spacing. Unless the reinforcement is very congested, the space between reinforcement and formwork cover is not normally taken into account as SCC can surround the bars and does not need to continuously flow through these spaces.
Examples of passing ability specifications are given below:
PA 1 structures with a gap of 80 mm to 100 mm, (e.g. housing, vertical structures)
PA 2 structures with a gap of 60 mm to 80 mm, (e.g. civil engineering structures)
For thin slabs where the gap is greater than 80 mm and other structures where the gap is greater than 100 mm no specified passing ability is required.
For complex structures with a gap less than 60 mm, specific mock-up trials may be necessary.
resistance
6.4.4 Segregation
Segregation resistance is fundamental for SCC in-situ homogeneity and quality. SCC can suffer from segregation during placing and also after placing but before stiffening. Segregation which occurs after placing will be most detrimental in tall elements but even in thin slabs, it can lead to surface defects such as cracking or a weak surface.
In the absence of relevant experience, the following general guidance on segregation resistance classes is given:
Segregation resistance becomes an important parameter with higher slump-flow classes and/or the lower viscosity class, or if placing conditions promote segregation. If none of these apply, it is usually not necessary to specify a segregation resistance class.
SR1 is generally applicable for thin slabs and for vertical applications with a flow distance of less than 5 metres and a confinement gap greater than 80 mm.
SR2 is preferred in vertical applications if the flow distance is more than 5 metres with a confinement gap greater than 80 mm in order to take care of segregation during flow.
SR2 may also be used for tall vertical applications with a confinement gap of less than 80 mm if the flow distance is less than 5 metres but if the flow is more than 5 metres a target SR value of less than 10% is recommended.
SR2 or a target value may be specified if the strength and quality of the top surface is particularly critical.
examples
6.5 Specification
The following table highlights the initial parameters and classes to be considered for specifying SCC in different applications. It does not take account of specific confinement conditions, element geometry, placing method or characteristics of the materials to be used in the concrete mix. Discussions should normally be held with the concrete producer before a final specification decision is made.
Properties of SCC for various types of application based on Walraven, 2003
Walraven J (2003) Structural applications of self compacting concrete Proceedings of 3rd RILEM International Symposium on Self Compacting Concrete, Reykjavik, Iceland, ed. Wallevik O and Nielsson I, RILEM Publications PRO 33, Bagneux, France, August 2003 pp 15-22
7 Constituent
materials
7.1 General
The constituent materials for SCC are the same as those used in traditional vibrated concrete conforming to EN 206-1. In most cases the requirements for constituents are individually covered by specific European standards. However, in order to be sure of uniform and consistent performance for SCC, additional care is needed in initial selection and also in the continual monitoring for uniformity of incoming batches.
To achieve these requirements the control of the constituent materials needs to be increased and the tolerable variations restricted, so that daily production of SCC is within the conformity criteria without the need to test and/or adjust every batch.
7.2 Cement
All cements which conform to EN 197-1 can be used for the production of SCC. The correct choice of cement type is normally dictated by the specific requirements of each application or what is currently being used by the producer rather than the specific requirements of SCC.
7.3 Additions
Due to the fresh property requirements of SCC, inert and pozzolanic/hydraulic additions are commonly used to improve and maintain the cohesion and segregation resistance. The addition will also regulate the cement content in order to reduce the heat of hydration and thermal shrinkage.
The additions are classified according to their reactive capacity with water:
TYPE I Inert or semi-inert ?Mineral filler (limestone, dolomite etc) ? Pigments
Pozzolanic ?Fly ash conforming to EN 450 ?Silica fume conforming to EN 13263
TYPE II
Hydraulic ?Ground granulated blast furnace slag
(If not combined in an EN 197-1 cement, national standards may apply until the new EN 15167 standard is published)
Additions, other than those combined in an EN 197-1 cement, may not be as well controlled in terms of particle size distribution and composition as some other concrete constituents so increased monitoring of deliveries may be necessary.
Self-compacting concrete is often selected for its high quality finish and good appearance but this may be compromised if the source of the addition does not have good colour consistency.
7.3.1 Mineral
fillers
The particle size distribution, shape and water absorption of mineral fillers may affect the water demand /sensitivity and therefore suitability for use in the manufacture of SCC. Calcium carbonate based mineral fillers are widely used and can give excellent rheological properties and a good finish. The most advantageous fraction is that smaller than 0.125 mm and in general it is desirable for >70% to pass a 0.063mm sieve. Fillers specifically ground for this application offer the advantage of improved batch to batch consistency of particle size distribution, giving improved control over water demand and making them particularly suitable for SCC compared with other available materials.
钢筋施工技术标准及工艺流程 本施工技术标准及工艺流程将参照相关国家规范、国家标准及建筑行业 标准制定，钢筋施工人员需依据建设施工设计图纸和施工方案等编制钢筋用 料单，并经项目技术负责人审核认可签字后开始施工。 钢筋施工标准及流程如下: 一、钢筋放样 根据施工图纸编制的钢筋用料单中应包含钢筋的规格、形状、长度、数量、应用部位等信息。根据结构施工图下料，做到长短料相配合，杜绝浪费。 二、钢筋进场 钢筋进场后需缓送轻放，分型号堆放整齐，下部距地面20公分，上部 覆盖薄膜，防止雨淋生锈。 三、钢筋加工 加工前应准备好的机械设备包括钢筋冷拉机、调值机、切断机、弯曲成型机、弯箍机、点焊机、对焊机、电弧焊机及相应吊装设备。各种设备在操作前检修完好，保证正常运转，并符合安全规定。 钢筋的加工制作应在专门的操作区域内进行，严禁在规定区域外加工操作。操作步骤如下： （1）除锈：钢筋加工前将钢筋表面的油渍、漆渍及浮皮、铁锈等清除干净，可结合冷拉工艺除锈，使其与混凝土的粘接效果达到最佳。 （2）调直：调直后应保证钢筋平直，经调直后的钢筋不得有局部弯曲、死弯、小波浪形，其表面伤痕不应使钢筋截面减少5%，无局部曲折。 （3）切断：钢筋的切断需遵循“先长后短，长短搭配，统筹排料”的原则，尽量减少和缩短钢筋短头，以节约钢材，避免浪费。 （4）弯曲成型：手工弯曲和机械弯曲相结合进行，钢筋弯曲后，弯曲内皮收缩、外皮延伸、轴线长度不变，弯曲点处不得有裂痕。 根据施工计划和现场实际情况将加工成型的钢筋成品按分批、分期码放整齐，挂牌标识，露天存放时应对钢筋成品采取保护措施，防止变形和生锈。
四、钢筋的安装绑扎 成品钢筋在吊装运送过程中应遵循就近原则，缓吊轻放，一次到位，避免对成品钢筋件造成毁坏变形。绑扎顺序由下至上、层次鲜明，合理规划。 （一）、基础钢筋绑扎 工艺流程：清理垫层→基础钢筋绑扎→画线或弹线→绑扎底板下层受力钢筋绑扎→预留、预埋→板的支座马凳铁通长设置→后浇带处止水带的安装→板的上层钢筋绑扎→复检 操作工艺： （1）绑扎前应沿轴线方向在垫层上画好等分线； （2）网格绑扎时交叉点需绑扎牢固，扎丝扣成八字形，防止网片歪曲变形； （3）钢筋搭接长度要符合国家规范和设计要求； （4）筏板基础长向钢筋用直螺纹连接，短向钢筋用闪光对焊连接； （二）、柱钢筋安装绑扎 工艺流程：清理基层杂物→安放和绑扎柱竖向受力筋→套柱箍筋→画箍筋间距线→绑扎箍筋→复检 操作工艺： （1）清理柱基处杂物，以便看清基轴线，安放柱子竖向钢筋和定位箍筋应焊接牢固，防止浇筑混凝土时发生位移； （2）按图纸设计间距套放箍筋，由上而下采用缠扣绑扎牢固，不得跳扣绑扎； （3）柱竖向钢筋采用机械或焊接连接时，其搭接长度和连接要求应复合设计规范要求； （4）箍筋的弯钩叠合处应沿拄子竖筋交错布置，并绑扎牢固； （5）柱筋保护层厚度应符合规范要求，如主筋外皮为25mm； （三）、梁钢筋安装绑扎 工艺流程：清理梁基底杂物→画主次梁箍筋间距→放主梁次梁箍筋→穿主梁底层纵筋及弯起筋→穿次梁底层纵筋并与箍筋固定→穿主梁上层纵向架立筋→按箍筋间距绑扎→穿次梁上层纵向钢筋→按箍筋间距绑扎→复检
基础钢筋绑扎施工工艺标准 10.1总则 10.1.1适用范围 适用于建筑结构工程的基础及底板钢筋绑扎。 10.1.2编制参考标准及规范 《混凝土结构设计规范》( GB50010—) ; 《混凝土结构工程施工质量验收规范》( GB50204—) ; 《钢筋焊接及验收规程》( JGJ18—96) ; 《建筑施工安全检查标准》( JGJ59—99) ; 《中国建筑工程总公司施工安全检查生产监督管理条例》; 钢筋、绑丝等相关材料标准和有关规定。 10.2术语、符号 10.2.1现浇结构 系现浇混凝土结构的简称, 是以现场支模并整体浇筑而成的混凝土结构。 10.2.2HPB235级钢筋 系指现行国家标准《钢筋混凝土用热轧光圆钢筋》( GB13013—1991) 中的Q235钢筋, 相当于原级别I级钢筋。 10.2.3HRB335( 20MnSi) 钢筋 系指现行国家标准《钢筋混凝土用热轧带肋钢筋》( GB1499—1998) 中的HRB335钢筋, 相当于原级别II级钢筋。 10.2.4HRB400( 20MnSiV、20MnSiNbv、20MnSiTi) 级钢筋
系指现行国家标准《钢筋混凝土用热轧带肋钢筋》( GB1499—1998) 中的HRB400钢筋, 相当于原级别III级钢筋。 10.2.5RRB400( K20MnSi) 级钢筋 系指现行国家标准《钢筋混凝土用余热处理钢筋》( GB13014—91) 中的KL400钢筋, 相当于原级别III级钢筋。 10.2.6La 钢筋锚固长度。 10.3基本规定 10.3.1一般规定 ( 1) 当钢筋的品种、级别或规格需作变更时, 庆办理材料代用手续。 ( 2) 浇筑混凝土前, 应进行钢筋隐蔽工程验收, 其内容包括: 1) 纵向受力钢筋的规格、数量、位置等; 2) 钢筋的连接方式、接头位置、接头数量、接头面积百分率等; 3) 箍筋、横向钢筋的品种、规格、数量、间距等; 4) 预埋件的规格、数量、位置等; 5) 避雷网线的布设与焊接等。 10.3.2质量目标 达到《混凝土结构工程施工质量验收规范》( GB50204—) 的要求, 并符合图纸及”施工组织设计”的要求。 10.4施工准备 10.4.1技术准备
1承台钢筋绑扎施工工艺 1.1执行标准 《混凝土结构工程施工质量验收规范》（GB50204—2002）（2010版）； 《混凝土结构设计规范》（GB50010—2010）； 《钢筋焊接及验收规程》（JGJ18—2012）； 《冷轧带肋钢筋混凝土结构技术规程》(JGJ95—2011)； 《中国建筑工程总公司建筑工程施工工艺标准》； 钢筋、绑扎丝等相关材料标准和有关规定。 1.2施工工艺流程和操作要点 1.2.1施工工艺流程 1.2.2操作要点
确定承台十字轴线，并用墨线弹在施工垫层地板上。经驻地
监理工程师核查、批准后绑扎。 2）划钢筋位置线：按图纸标明的钢筋间距，算出底板实际需用的钢筋根数，一般让靠近底板模板边的那根钢筋离模板边为5cm，在底板上弹出钢筋位置线。 2、钢筋加工： 1）钢筋清理：钢筋表面应洁净，粘着的油污、泥土、浮锈使用前必须清理干净。 2）钢筋调直：可用机械或人工调直。经调直后的钢筋不得有弯曲、死弯、小波浪形，其表面伤痕不应使钢筋截面减小5﹪. 3）钢筋截断：应根据钢筋直径、长度和数量，长短配搭，先断长料后端短料，尽量减少和缩短钢筋短头，以节约钢材。 3、钢筋运输： 将加工好的钢筋运往施工现场时，应做好钢筋编号，并做好钢筋的运输管理，防止钢筋在运输过程中发生变形，被污染。 4、底板钢筋绑扎： 1）按弹出的钢筋位置线，先铺下层钢筋。根据底板受力情况，决定下层钢筋哪个方向钢筋在下面，一般情况下先铺短向钢筋，再铺长向钢筋。 2）钢筋绑扎时，靠近外围两行的相交点每点都绑扎，
中间部分的相交点可相隔交错绑扎，双向受力的钢筋必须将钢筋交叉点全部绑扎。 3）摆放底板混凝土保护层用砂浆垫块，垫块厚度等于保护层厚度，按每1m左右距离梅花型摆放。如底板较厚或用钢筋较大，摆放距离可缩小。 5、钢筋固定： 1）先绑2～4根竖筋，并画好横筋分档标志。然后在下部及齐胸处绑两根横肋定位，并画好竖筋分档标志。一般情况横筋在外。竖筋在里，所以先绑竖筋后绑横筋。横竖筋的间距及位置应符合设计要求。 2）在钢筋外侧应绑上带有铁丝的砂浆垫块，以保证保护层的厚度。 6、顶板钢筋绑扎： 在进行顶板钢筋绑扎前应该现对该基础再次施工放样，即对已经的施工完成的钢筋绑扎进行检查，能确定基础的平面尺寸。根据放样进行顶板的钢筋绑扎。绑扎的工艺与底板的施工工艺基本一致。 7、预埋件钢筋绑扎： 1）根据弹好的肋板（立柱）位置线，将肋板（立柱）伸入基础的插筋绑扎牢固，插入基础深度要符合设计要求，甩出长度不宜过长，其上端应采取措施保证甩筋垂直，不歪斜、倾倒、变位。
房屋建筑工程钢筋绑扎施工方法 一、基础钢筋绑扎施工方法和施工措施 1工艺流程： 划钢筋位置线→运钢筋到使用部位→绑底板及梁钢筋→绑墙钢筋 2划钢筋位置线：按图纸标明的钢筋间距，算出底板实际需用的钢筋根数，一般让靠近底板模板边的那根钢筋离模板边为5cm，在底板上弹出钢筋位置线（包括基础梁钢筋位置线）。 3绑基础及基础梁钢筋 3.l按弹出的钢筋位置线，先铺底板下层钢筋。根据底板受力情况，决定下层钢筋哪个方向钢筋在下面，一般情况下先铺短向钢筋，再铺长向钢筋。 3.2钢筋绑扎时，靠近外围两行的相交点每点都绑扎，中间部分的相交点可相隔交错绑扎，双向受力的钢筋必须将钢筋交叉点全部绑扎。如采用一面顺扣应交错变换方向，也可采用八字扣，但必须保证钢筋不位移。 3.3摆放混凝土保护层用砂浆垫块，垫块厚度等于保护层厚度，按每1m左右距离梅花型摆放。如基础底板较厚或基础梁及底板用钢量较大，摆放距离可缩小，甚至砂浆垫块可改用铁块代替。 3.4底板如有基础梁，可分段绑扎成型，然后安装就位，或根据梁位置线就地绑扎成型。 3.5基础底板采用双层钢筋时，绑完下层钢筋后，摆放钢筋马凳或钢筋支架（间距以1m左右一个为宜），在马凳上摆放纵横两个方向定位钢筋，钢筋上下次序及绑扣方法同底板下层钢筋。 3.6钢筋如有绑扎接头时，钢筋搭接长度及搭接位置应符合施工规范要求，钢筋搭接处应用铁丝在中心及两端扎牢。如采用焊接接头，除应按焊接规程规定抽取试样外，接头位置也应符合施工规范的规定。 3.7由于基础底板及基础梁受力的特殊性，上下层钢筋断筋位置应符合设计
要求。 3.8根据弹好的柱位置线，将柱伸入基础的插筋绑扎牢固，插入基础深度要符合设计要求，甩出长度不宜过长，其上端应采取措施保证甩筋垂直，不歪斜、倾倒、变位。 二、构造柱、圈梁钢筋绑扎施工方法和施工措施 1构造柱钢筋绑扎： 1.1工艺流程：预制构造柱钢筋骨架→修整底层伸出的构造柱塔接筋→安装 构造柱钢筋骨架→绑扎搭接部位箍筋 1.2预制构造柱钢筋骨架： 1.2.1先将两根竖向受力钢筋平放在绑扎架上，并在钢筋上画出箍筋间距。 1.2.2根据画线位置，将箍筋套在受力筋上逐个绑扎，要预留出搭接部位的长度。为防止骨架变形，宜采用反十字扣或套扣绑扎。箍筋应与受力钢筋保持垂直；箍筋弯钩叠合处，应沿受力钢筋方向错开放置。 1.2.3穿另外二根受力钢筋，并与箍筋绑扎牢固，箍筋端头平直长度不小于10d（d为箍筋直径），弯钩角度不小于135°。 1.2.4在柱顶、柱脚与圈梁钢筋交接的部位，应按设计要求加密柱的箍筋，加密范围一般在圈梁上、下均不应小于六分之一层高或45cm，箍筋间距不宜大于10cm（柱脚加密区箍筋待柱骨架立起搭接后再绑扎）。 1.3修整底层伸出的构造柱搭接筋：根据已放好的构造柱位置线，检查搭接筋位置及搭接长度是否符合设计和规范的要求。底层构造柱竖筋与基础圈梁锚固；无基础圈梁时，埋设在柱根部混凝土座内， 1.4安装构造柱钢筋骨架：先在搭接处钢筋上套上箍筋，然后再将预制构造柱钢筋骨架立起来，对正伸出的搭接筋，搭接倍数不低于35d，对好标高线，在竖筋搭接部位各绑3个扣。骨架调整后，可绑根部加密区箍筋。 1.5绑扎搭接部位钢筋：
西蒋峪房地产开发项目一标段 9#楼钢筋施工方案 编制: 审核: 审批: 建筑单位: 济南城市建设投资集团有限公司 监理单位: 济南市建设监理有限公司 施工单位: 中国建筑第八工程局有限公司 二〇一五年五月四日
目录 一工程概况 (1) 二编制依据 (1) 三施工准备 (1) 3.1 技术准备 (1) 3.2 机具准备 (3) 3.3 材料准备 (3) 四主要施工方法 (3) 4.1 工艺流程 (4) 4.2 钢筋堆放 (5) 4.3 钢筋加工 (5) 4.4 钢筋连接 (6) 4.5 钢筋绑扎 (8) 五质量要求 (16) 6.1 钢筋绑扎及预埋件的允许偏差 (16) 6.2 钢筋加工的允许偏差 (17) 6.3 质量控制要点 (17) 六安全文明措施 (17) 七成品保护措施 (18)
一工程概况 西蒋峪B地块房地产开发项目9#楼，拟建场地位于济南市历下区龙鼎大道以西，原西蒋峪村内，东临孟家水库，南临济南西蒋峪公租房项目，北距奥体中心约2.7公里。9#楼位于市政道路北侧，与3#车库相连（与车库位置见下图），地下3层，地上20层，东西长59.19m，南北长18.5m，总高度约69.9m。 本工程为剪力墙结构，剪力墙抗震等级为三级，基础为条形+筏板基础，基础高度1000mm，基础底标高-10.920m。 二编制依据 西蒋峪房地产开发项目一标段建筑、结构设计图纸 《地基与基础工程质量验收规范》GB50202-2002 《混凝土结构工程施工质量验收规范》GB50204-2002 《钢筋机械连接通用技术规程》JGJ107-2010 《钢筋混凝土用热轧带肋钢筋验收标准》GB1499.1-2007 《钢筋混凝土用热轧带肋钢筋验收标准》GB1499.2-2008 《建筑机械使用安全技术规程》JGJ33-2001 《施工现场临时用电安全技术规范》JGJ46-2005 《混凝土结构施工图平面整体表示方法制图规则和构造详图》11G101-1 《混凝土结构施工图平面整体表示方法制图规则和构造详图》11G101-2 《混凝土结构施工图平面整体表示方法制图规则和构造详图》11G101-3 三施工准备 3.1 技术准备 1、由项目技术负责人组织有关人员学习施工规范和工艺标准，熟悉施工图纸，并结合实际讨
一、施工准备 1材料及主要机具： (1)钢筋：应有出厂合格证，按规定作力学性能复试。当加工过程中发生脆断等特殊情况，还需作化学成分检验。钢筋应无老锈及油污。 (2) 铁丝：可采用20～22号铁丝或镀锌铁丝。铁丝的切断长度要满足使用要求。 (3) 控制混凝土保护层用的砼垫块、各种挂钩或撑杆等。 (4) 工具：钢筋钩子、撬棍、扳子、绑扎架、钢丝刷子、粉笔、尺子等。 2作业条件： (1)按施工现场平面图规定的位置，将钢筋堆放场地进行清理、平整。准备好垫木，按钢筋绑扎顺序分类堆放，并将锈蚀进行清理。 (2) 核对钢筋的级别，型号、形状、尺寸及数量是否与设计图纸及加工配料单相同。 (3) 当施工现场地下水位较高时，必须有排水及降水措施。 (4) 熟悉图纸，确定钢筋穿插就位顺序，并与有关工种作好配合工作，如支模、管线、防水施工与绑扎钢筋的关系，确定施工方法，作好技术交底工作。 (5) 根据地下室防水施工方案，底板钢筋绑扎前做完底板下防水层及保护层；支完底板四周模板（或砌完保护墙，做好防水层）。当地下室外墙防水采用内贴法施工时，在绑扎墙体钢筋之前砌完保护墙，做好防水层及保护层。 二、操作工艺 (1)、工艺流程： → → →
(2)划钢筋位置线：按图纸标明的钢筋间距，算出底板实际需用的钢筋根数，一般让靠近底板模板边的那根钢筋离模板边为5cm，在底板上弹出钢筋位置线（包括基础梁钢筋位置线）。 (3)绑基础底板及基础梁钢筋 1）按弹出的钢筋位置线，先铺底板下层钢筋。根据底板受力情况，决定下层钢筋哪个方向钢筋在下面，本工程先铺长向钢筋，再铺短向钢筋。 2）钢筋绑扎时，靠近外围两行的相交点每点都绑扎，中间部分的相交点可相隔交错绑扎，双向受力的钢筋必须将钢筋交叉点全部绑扎。如采用一面顺扣应交错变换方向，也可采用八字扣，但必须保证钢筋不位移。 3）摆放底板混凝土保护层用砼垫块，垫块厚度等于保护层厚度，按每1m左右距离梅花型摆放。如基础底板较厚或基础梁及底板用钢量较大，摆放距离可缩小。 4）底板如有基础梁，可分段绑扎成型，然后安装就位，或根据梁位置线就地绑扎成型。 5）基础底板采用双层钢筋时，绑完下层钢筋后，摆放钢筋马凳或钢筋支架（间距以1m左右一个为宜），在马凳上摆放纵横两个方向定位钢筋，钢筋上下次序及绑扣方法同底板下层钢筋。 6）底板钢筋如有绑扎接头时，钢筋搭接长度及搭接位置应符合施工规范要求，钢筋搭接处应用铁丝在中心及两端扎牢。如采用焊接接头，除应按焊接规程规定抽取试样外，接头位置也应符合施工规范的规定。 7）由于基础底板及基础梁受力的特殊性，上下层钢筋断筋位置应符合设计要求。 8）根据弹好的墙、柱位置线，将墙、柱伸入基础的插筋绑扎牢固，插入基础深度要符合设计要求，甩出长度不宜过长，其上端应采取措施保证甩筋垂直，不歪斜、倾
柱钢筋绑扎施工工艺Last revision on 21 December 2020
柱钢筋绑扎施工工艺柱筋定位卡示意图柱筋定位卡制作实例图 框架柱绑扎柱根部500mm范围内做法 柱钢筋绑扎施工工艺： 1、工艺流程： 柱筋绑扎→安装柱筋定位卡具→平台混凝土浇筑→拆除定位卡具→套柱箍筋→柱主筋连接→绑扎竖向受力筋→画箍筋控制线→箍筋绑扎→保护层设置 2、操作要点： 定位卡具制作：柱钢筋绑扎前，根据柱主筋间距，制作钢筋卡具。卡具固定筋采用φ14钢筋、限位筋采用φ6钢筋，限位筋间距为柱主筋直径+10mm主筋定位卡制作完成后，可涂刷黄色油漆标示。 柱筋绑扎：根据钢筋位置线校正板面上部预留柱筋，吊装绑扎柱筋。 柱筋定位卡具放置：按照图纸要求绑扎好柱钢筋。绑扎成型后，在距楼面标高上20cm处安装定位卡具，并与主筋绑扎牢固。 套柱箍筋：按图纸要求间距，计算好每根柱箍筋数量，先将箍筋套在下层伸出的搭接筋上，然后立柱子钢筋（包括采用机械连接或电渣压力焊连接施工），当采用绑扎搭接连接时，在搭接长度内，绑扎不少于3个，绑扣要向柱中心。如果柱子主筋采用光圆钢筋搭接时，角部弯钩应与模板成45度，中间钢筋的弯钩应与模
板成90度 竖向受力钢筋连接：柱主筋≥Φ16mm采用直螺纹套筒机械连接，Φ12mm、Φ14mm根据现场实际情况考虑电渣压力焊连接或者钢筋绑扎搭接连接，<Φ12mm采用钢筋搭接绑扎连接。绑扎接头的搭接长度应符合设计要求和规定，框架梁、牛腿及柱帽等钢筋，应放在柱的纵向钢筋内侧。 画箍筋间距线：在立好的柱子竖向钢筋上，按图纸要求用粉笔画箍筋间距线，第一根箍筋距离楼面一般为50mm 柱箍筋绑扎： 保护层设置：保护层垫块应绑在柱纵向钢筋外皮上，使用水泥砂浆垫块、塑料卡，间距控制在1000mm左右以保证主筋保护层厚度尺寸正确。柱筋绑扎后，不得攀爬。在混凝土面以上500mm范围内主筋采用塑料薄膜缠绕，减少混凝土对主筋的污染，混凝土浇筑完成后，压光时将塑料薄膜清理干净，并将钢筋周边混凝土抹压密实。 3、质量要求： 钢筋进场时，应按现行国家标准《钢筋混凝土用热轧带肋钢筋》等的规定抽取试件作力学性能检验，其质量必须符合有关标准的规定。 钢筋规格、形状、尺寸、数量、锚固长度、接头位置，必须符合设计施工图纸及规范的规定，如有变更，需办理设计变更文件。箍筋末端应弯成135°平直部分长度为10d。
1 钢筋工程施工工艺 1.1 适用范围 1.1.1 本工艺适用于本项目工程混凝土工程的钢筋加工、制作、绑扎作业。 1.2施工准备 1.2.1 材料要求 1 混凝土结构所用的钢筋其品种、规格、性能等应符合设计要求和现行国家产品标准。 2 钢筋应按进场的批次进行检查和验收，检验合格后方可使用。进场检验应符合下列规定： 1）每批钢筋应由同一牌号、同一炉罐号、同一规格、同一等级、同一交货状态组成，并不得大于60t。 2）检查每批钢筋的外观质量。钢筋表面不得有裂纹、结症和折叠；表面的凸块和其他缺陷的深度和高度不得大于所在部位的尺寸的允许偏差（带肋钢筋为横肋的高度)；测量本批钢筋的直径偏差； 3）经外观检查合格的每批钢筋中任选两根钢筋，在其上各截取1组试样，每组试样各制3根试件，分别作拉伸（含抗拉强度、屈服点、伸长率）和冷弯试验。 带肋钢筋应按规定增加反向弯曲试验项目。 4）当试样有1个试验项目不符合要求时，应另取2倍数量的试件对不合格项目作第2 次试验，当仍有1根不合格时，则该批钢筋应判为不合格。 3 在浇筑混凝土之前应进行钢筋的隐蔽工程验收。钢筋的数量、位置和连接方式应符合设计要求，预埋件的规格、数量和位置应符合设计要求。
4 钢筋在运输和储存时，不得损坏标志，存放时应按钢筋类型、直径、钢号、批号、厂家等条件进行分类堆放，设分类标志牌、不得混淆；同时应避免锈蚀和污染（一般应架空地面0.3m以上，并苫盖防雨)；在码放时应将外观检查不合格的钢筋及时剔除。 5 钢筋的级别、种类和直径应按设计要求采用。当需要代换时，应由原设计单位做变更设计。 6 工地应对运进的钢筋进行检验，作为使用本批钢筋的使用依据。 7 经检验合格的钢筋在加工和安装过程中出现异常现象（如脆断、焊接性能不良或力学性能显著不正常等）时，应作化学成分分析。 8 当对钢筋质量或类别有疑问时，应根据实际情况进行抽样鉴定，并不得用于主要承重结构的重要部位。 9 焊接用电焊条应与钢材强度相适应，焊条质量应符合现行国家标准《碳钢焊条》GB/ T5117的规定。 1.2.2 施工机具与设备 1 钢筋加工设备（钢筋切断机、钢筋调直机、数控钢筋弯曲机、数控卷笼机、电焊机)，钢筋笼运输设备（运输汽车)、吊装设备（吊车）等。 2 钢筋绑扎工具（钢筋勾、石笔、墨斗、钢尺、撬棍等）。 1.2.3 作业条件 1 现场道路畅通，施工场地已清理平整，现场用水、用电接通，备有夜间照明设施。 2 钢筋工程所需的原材料数量已备足，进场。 3 钢筋加工场地应平整坚实，钢筋加工机械、焊接设备按平面布置图，合理确定安装位置。设备测试和试运转检测合格。 1.2.4 技术准备 1 根据施工部位、结构型式、环境条件、工程量、安全要求等因素，制定专项方案批准后实施。 2 技术交底和安全交底，并履行书面交底手续；熟悉施工图纸及配筋图。 3 按结构部位，编制钢筋加工单并通过专业工程师批准。 4 经专业技术培训，考试合格；焊工等专业技术工种应持证上岗。 1.3 操作工艺 1.3.1 工艺流程 钢筋加工场建设→钢筋加工设备安装→原材料进场检查、检测试验→钢筋下料→钢筋加工→钢筋焊接→钢筋安装→检查、检测。 1.3.2 钢筋加工场建设
基础钢筋绑扎施工工艺流程：基础垫层完成T弹底板钢筋位置线T钢筋半成品运 输到位T按线布放钢筋T绑扎。 操作工艺： 1、将基础垫层清扫干净，用石笔和墨斗在上面弹放钢筋位置线。 2、将钢筋位置线布放基础钢筋。 3、绑扎钢筋。四周两行钢筋交叉点每点绑扎牢。中间部分交叉点可相隔交错扎 牢，但必须保证受力钢筋不位移。双向主筋的钢筋网，贝懦将全部钢筋相交点 扎牢。相邻绑扎点的钢丝扣成八字形，以免网片歪斜变形。 4、基础底板采用双层钢筋网时，在上层钢筋网下面应设置钢筋撑脚或混凝 土撑脚，以保证钢筋位置正确，钢筋撑脚下应垫在下片钢筋网上。见图: 钢筋撑脚的形式和尺寸如图，图一所示类型撑脚每隔1m放置1个。其直径选用：当板厚h w 300mrfl寸为8~10mm当板厚h=300~500,时为12~14mm当板厚 h>500mn时，选用图二所示撑脚，钢筋直径为16~18mm沿短向通长布置，间距以 能保证钢筋位置为准。 5、钢筋的弯钩应朝上，不要倒向一边：双层钢筋网的上层钢筋弯钩应朝下。 6、独立柱基础底板钢筋为双向弯曲，其底面短向的钢筋应放在长向钢筋的 上面。
7、现浇柱与基础连接用的插筋，其箍筋尺寸应比柱的箍筋尺寸小一个柱筋直径，以 便连接。箍筋的位置一定要绑扎固定牢靠，以免造成柱轴线偏移。 & 基础中纵向受力钢筋的混凝土保护层厚度不应小于40mm当无垫层时，不应小于70mm。 9、钢筋的连接： ①受力钢筋的接头宜布置在受力较小处。接头末端至钢筋弯起点的距离不应小于钢筋直 径的10倍。 ②若采用绑扎搭接接头，则接头相邻纵向受力钢筋的绑扎接头宜相互错开。钢筋绑扎 接头连接区段的长度为1.3 倍搭接长度。凡搭接接头中点位于该区段的搭接接头均属于同一连接区段。位于同一区段内的受拉钢筋搭接接头百分率为25%； ③当钢筋的直径d>28mm时，不宜采用绑扎接头； ④纵向受力钢筋采用机械连接接头或焊接接头时，连接区段的长度为35d （d 为纵向受力钢筋的较大值）且不小于500m m。同一连接区段内，纵向受力钢 筋的接头面积百分率应符合设计规定，当设计无规定时，应符合下列规定：一、在 受拉区不宜大于50%；二、直接承受动力荷载的基础中，不宜采用焊接接头；当采用机械连接接头时，不应大于50%。 10、基础浇筑前，把基础面上预留墙柱插筋扶正理顺，保证插筋位置准确。 11、承台钢筋绑扎前，一定要保证桩基伸出钢筋到承台的锚固长度。 剪力墙钢筋绑扎施工工艺标准 本标准适用于外板内模、外砖内模、全现浇等结构形式的剪力墙钢筋绑扎。工程 施工应以设计图纸和有关施工质量验收规范为依据 一、材料要求根据设计要求，工程所用钢筋种类、规格必须符合要求，并经检验合格。
梁板钢筋绑扎施工工艺 平台板钢筋绑扎 梁柱节点钢筋绑扎 梁板钢筋绑扎施工工艺： 1、工艺流程： 1.1梁钢筋绑扎工艺流程 1.1.1、模内绑扎：画主次梁 箍筋间距→放主梁次梁箍筋→穿 主梁底层纵筋及弯起筋→穿次梁底层纵筋并与箍筋固定→穿主梁上层纵向架立筋→按箍筋间距绑扎→穿次梁上层纵向钢筋→按箍筋间距绑扎 1.1.2、、模外绑扎（先在梁模板上口绑扎成型后再入模内）：画箍筋间距→在主次梁模板上口铺横杆数根→在横杆上画放箍筋→穿主梁下层纵筋→穿次梁下层钢筋→穿主梁上层钢筋→按箍筋间距绑扎→穿次梁上层纵向钢筋→按箍筋间距绑扎→抽出横杆落骨架于模板内 1.2板钢筋安装工艺流程 清理模板→模板上画线→绑板下受力筋→绑负弯矩钢筋 2、操作要点：
2.1在梁侧模板上画出箍筋间距，摆放箍筋。 2.2先穿主梁的下部纵向受力钢筋及弯起钢筋，将箍筋按已画好的间距逐个分开；穿次梁的下部纵向受力钢筋及弯起钢筋，并套好箍筋；放主次梁的架立筋；隔一定间距将架立筋与箍筋绑扎牢固；调整箍筋间距使间距符合设计要求，绑架立筋，再绑主筋，主次梁同时配合进行。 2.3框架梁上部纵向钢筋应贯穿中间节点，梁下部纵向钢筋伸入中间节点，锚固长度及伸过中心线的长度要符合设计要求。框架梁纵向钢筋在端节点内的锚固长度也要符合设计要求。 2.4绑梁上部纵向筋的箍筋，宜用套扣法绑扎。箍筋的接头（弯钩叠合处）应交错布置在两根架立钢筋上，其余同柱。 2.5箍筋在叠合处的弯钩，在梁中应交错绑扎，箍筋弯钩为135度，平直部分长度为10d，如做成封闭箍时，单面焊缝长度为5d。 2.6梁端第一个箍筋应设置在距离柱节点边缘50mm处。梁端与柱交接处箍筋应加密，其间距与加密区长度均要符合设计要求。 2.7板、次梁与主梁交叉处，板的钢筋在上，次梁的钢筋居中，主梁的钢筋在下；当有圈梁或垫梁时，主梁的钢筋在上。在主、次梁受力筋下均应垫垫块（或塑料卡），保证
桥梁钢筋绑扎施工工艺标准 FHEC-QH-28-3-2007 1、适用范围 本工艺标准适用于桥梁工程中桩基、承台、墩柱、盖梁、T梁等的钢筋绑扎工程。 2、编制主要应用标准和规范 2.1中华人民共和国行业标准《公路桥涵施工技术规范》JTJ 041-2000 2.2中华人民共和国行业标准《公路工程质量检验评定标准》JTG F80/1-2004 2.3中华人民共和国国家标准《钢筋混凝土用热轧光圆钢筋》GB 13013-91 2.4中华人民共和国国家标准《钢筋混凝土用热轧带肋钢筋》GB 1499-1998 2.5中华人民共和国国家标准《低碳钢热轧圆盘条》GB 701-1997 3施工准备 3.1技术准备 3.1.1熟悉图纸，编制单项钢筋绑扎施工组织设计。 3.1.2严格按照图纸要求进行钢筋下料。 3.1.3向各钢筋班组进行书面的一级技术交底。 3.2材料准备 3.2.钢筋：钢筋进场有出厂合格证和出厂检验报告，钢筋表面或每捆（每盘）钢筋均有标志。钢筋进场后应按有关规定见证取样送检作力学性能复试。当加工过程中发生脆断等特殊情况，还需作化学成分检验。钢筋应无老锈及油污。 3.2.2铁丝：可采用20~22号铁丝（为烧丝）或镀锌铁丝（铅丝）。铁丝切断长度
要满足使用要求。 3.2.3垫块：根据钢筋骨架保护层的厚度选用大小不同的垫块。桩基所用垫块为水泥砂浆制成，强度等级同混凝土设计强度等级，厚度同保护层，其它结构根据保护层厚度选择3cm、5cm的塑料垫块，该种垫块必须有一定的抗压强度，能够承受承台或盖梁的重压，侧面用垫块宜选择圆形，底面用垫块宜选择方形。 3.2.4钢管：作为绑扎骨架的辅助材料，适用于吊装的骨架，如方形墩柱、盖梁骨架等，通过钢管搭设架子，在架子上进行绑扎。 3.3机具准备 主要机具：钢筋钩子、撬棍、扳子、钢丝刷子、手推车、粉笔、尺子等。 3.4作业条件 3.4.1按施工平面图中指定的位置，将钢筋堆放和加工场地进行清理、平整。按规格、使用部位、编号、钢筋绑扎顺序分类，分别加垫木堆放。 3.4.2钢筋绑扎前，应检查有无锈蚀，除锈之后再运至绑扎部位。 3.4.3熟悉图纸、按设计要求检查已加工好的钢筋规格、形状、数量、尺寸是否正确。 3.4.4桥面铺装网片几何尺寸规格及焊接质量检验合格后可使用。 3.4.5根据设计图纸及工艺标准要求，确定钢筋穿插就位顺序，并与有关工种作好配合工作，确定施工方法，向班组技术交底。 3.4.6在现场绑扎（如承台、盖梁等）时，可以在底模上用粉笔画好主筋的位置，通过垫块提前预留保护层的厚度。 4、施工操作工艺 4.1桩基钢筋绑扎工艺
钢筋现场绑扎工法 本施工工艺适用于混凝土结构中的钢筋绑扎工程。 １.材料性能要求 (１）钢筋原材: 钢筋出厂质量证明书、按规定作力学性能复试和见证取样试验。当加工过程中发生脆 (2）成型钢筋 断等特殊情况,还需做化学成分检验。钢筋应无老锈及油污。?必须符合配料单的规格、型号、尺寸、形状、数量,并应进行标识。成型钢筋必须进行覆盖,防止雨淋生锈。?（3）铁丝 可采用20～22号铁丝(火烧丝）或镀锌铁丝(铅丝)。铁丝切断长度要满足使用要求。? (4）垫块 用水泥砂浆制成50mｍ矩形，厚度同保护层，垫块内预埋20～２2号火烧丝。或用塑料卡、拉筋、支撑筋。 2.施工工具与机具 钢筋钩子、撬棍、扳子、绑扎架、钢丝刷子、手推车、粉笔、尺等。 3.作业条件 (１)钢筋进场后资料齐全,复试合格。做完复试，按施工平面图中指定的位置,按规格、使用部位和编号分别加垫木堆放。 (2)钢筋绑扎前，应检查有无锈蚀,除锈之后再运至绑扎部位。 (3)钢筋绑扎前先认真熟悉图纸,检查配料表与图纸设计是否有出入，仔细检查成品尺寸、形状是否与下料表相符。核对无误后方可进行绑扎。 (4）做好抄平放线工作,弹好水平标高线，柱、墙外皮尺寸线。 （5)根据弹好的外皮尺寸线,检查下层预留搭接钢筋的位置、数量、长度，如不符合要求时,应进行处理。绑扎前先按１：6整理调直下层伸出的搭接筋,并将锈蚀、水泥砂浆等污垢清除干净。 (6)根据标高检查下层伸出搭接筋处的混凝土表面标高(柱顶、墙顶)是否符合图纸要求,混凝土施工缝处要剔凿到露出石子并清理干净。 （7)按要求搭好脚手架。 4.施工工艺 (1)底板及承台钢筋绑扎 弹出钢筋位置线→先绑扎承台、地梁钢筋→铺底板下层钢筋→摆放钢筋马磴→绑扎上
城关街道东街村、丁家洼村定向安置房 项目1#楼 钢筋加工安装施工方案 建设单位：北京燕房新城投资有限公司 监理单位：北京科信工程管理有限公司 施工单位：北京順腾建筑工程有限责任公司 编制人：张艳水编制日期2014.5.8 审核人：谢福全审核日期2014.5.9
目录 1编制依据 (3) 2工程概况 (3) 3施工准备 (5) 4主要施工方法 (8) 5保证保护层厚度的措施 (25) 6季节施工 (27) 7质量要求 (28) 8应注意的问题 (30) 9成品保护措施 (30) 10安全、环保及文明施工要求 (31)
1编制依据 1.1城关街道东街村、丁家洼村定向安置房项目1#楼施工图纸、洽商、规范标准以及施工现场的实 际情况。 1.2施工图纸 1.3主要规范、规程 2工程概况 2.1 建施设计概况表2-2
2.2 结施设计概况表2-3
2.3流水段划分 本工程按基础后浇带和主体伸缩缝划分为三个流水段，其中第一段1－19轴。第二段20-38轴。第三段39-57轴。 3施工准备 3.1技术准备 熟悉施工图纸，学习有关规范、规程，按规范要求编制钢筋施工方案，包括基础底板、剪力墙、框架梁、连梁、板钢筋等的加工、绑扎等施工内容。 ①组织工人学习直螺纹接头的工艺操作、钢筋加工、绑扎等施工工艺标准。 ②熟悉钢筋直螺纹连接工艺规程及规范要求。 ③按设计要求放样，检查已加工好的钢筋规格、形状、数量全部正确。 ④做好抄平放线工作，弹好水平标高线，柱、墙外皮尺寸线。 ⑤按设计、规范列出本工程墙柱筋接头锚固一览表(包括错开百分比、错开长度、百分比系数)，根据弹好的外皮尺寸线，检查下层预留搭接钢筋的位置、接头百分比、错开长度。如不符合要求时，要进行处理。绑扎前保护层偏位按1：6调正伸出的搭接筋，并将锈蚀、水泥砂浆等污垢清除干净。
砖混结构钢筋绑扎工程施工技术方案 一、施工准备 （一）作业条件 1.核对钢筋品种、级别、规格、形状、尺寸、数量、位置是否与设计图纸及加工配料单相同。 2.弹好标高水平线及构造柱的外皮线。 3.构造柱钢筋绑扎前，柱板施工缝已处理完毕，柱筋调整完毕并办理完隐检手续。 （二）材质要求 1.钢筋：应有产品合格证、出厂检测报告和进场复验报告。钢筋应无老锈及油污。 2.绑丝：可采用20?22#铁丝或火烧丝（根据钢筋的规格确定）。 3.控制混凝土保护层用的塑料卡子、塑料垫块应有足够的承载强度, 塑料垫块的规格尺寸根据钢锯的直径和设计的钢筋混凝土保护层厚度确定（或现场预制水泥砂浆保护层垫块）。 （三）施工机具 钢筋弯曲机、卷扬机、钢筋切断机、钢筋钩子、撬棍、钢筋扳子、绑扎架、钢丝刷、粉笔、尺子等。 二、质量要求 具体要求请参照本人文档“箱型基础工程”章节中“钢筋工程”相应部分。 三、工艺流程 （一）构造柱钢筋绑扎 加工构造柱钢筋-施工缝混凝土表面凿毛、修整底层伸出的构造柱搭接筋-安装构造柱钢筋骨架-绑扎搭接部位钢筋 （二）圈梁钢筋绑扎 画钢筋位置线-放箍筋-穿圈梁受力筋-绑扎箍筋 （三）剪力墙钢筋绑扎 修理伸出筋-绑扎（焊接）节点竖向钢筋-绑扎墙体箍筋-网片定位—修整四、操作工艺 （一）构造柱钢筋绑扎 1.制作构造柱钢筋骨架 (1)先将两根竖向受力钢筋平放在绑扎架上，并在钢筋上画出箍筋间距。
(2)根据画线位置，将箍筋套在受力筋上逐个绑扎，要预留出搭接部位的长度。为防止骨架变形，宜采用反十字扣或缠扣绑扎。箍筋应与受力钢筋保持垂直；箍筋弯钩叠合处，应沿受力钢筋方向错开放置。为防止骨架在运输中变形，构造柱对角钢筋之间用弯起筋绑扎固定。 (3)穿另外二根受力钢筋，并与箍筋绑扎牢固。箍筋端头弯钩角度为135°,其弯钩的弯曲直径应大于受力钢筋的直径，且不小于箍筋直径的2.5倍；箍筋平直段长度不应小于箍筋直径的10倍。 (4)在柱顶、柱脚与圈梁钢筋交接的部位，应按设计要求加密柱的箍筋；无设计要求时加密范围一般在圈梁向上、向下500mm范围，箍筋间距为100m(柱脚加密区箍筋待柱骨架立起搭接后再绑扎)。 2.修整底层伸出的构造柱搭接筋。根据已放好的构造柱位置线，检 查搭接筋位置及搭接长度是否符合设计和抗震规范的要求。底层构造柱竖筋与基础圈梁锚固要求：有设计要求时，应按设计要求进行施工；无设计要求时，无基础圈梁时，埋设在垫层或基础混凝土座内。示。当墙体附有管沟时，构造柱埋设深度应大于沟深。 3.安装构造柱钢筋骨架。先在搭接处的钢筋套上箍筋，注意箍筋应交错布置。然后再将预制构造柱钢筋骨架立起来，对正伸出的搭接筋，对好标高线，在竖筋搭接部位各绑3个扣，两端中间各一扣。骨架调整后，可以顺序从根部加密区箍筋开始往上绑扎。 4.绑扎搭接部位钢筋。 (1)构造柱钢筋必须与各层纵横墙的圈梁钢筋绑扎连接，形成一个圭寸闭框架。 (2)在砌砖墙大马牙槎时，沿墙高每50cm埋设两根? 6.5水平拉结筋，与构造柱钢筋绑扎连接。 (3)砌完砖墙后，应对构造柱钢筋进行修整，以保证钢筋位置及间距准确。 (二)圈梁钢筋的绑扎 1.一般采用预制圈梁钢筋骨架，然后按编号吊装就位进行组装后支模板。也可现场绑扎，后支模板，一般采用硬架支模方法。如在模内绑扎时，按设计图纸要求间距，在模板侧帮画箍筋位置线。放箍筋后穿受力钢筋。箍筋搭接处应沿受力钢筋互相错开。 2.圈梁与构造柱钢筋交叉处，圈梁钢筋放在构造柱受力钢筋内侧。
基础钢筋绑扎施工工艺流程：基础垫层完成→弹底板钢筋位置线→钢筋半成品运输到位→按线布放钢筋→绑扎。 操作工艺： 1、将基础垫层清扫干净，用石笔和墨斗在上面弹放钢筋位置线。 2、将钢筋位置线布放基础钢筋。 3、绑扎钢筋。四周两行钢筋交叉点每点绑扎牢。中间部分交叉点可相隔交 错扎牢，但必须保证受力钢筋不位移。双向主筋的钢筋网，则需将全部 钢筋相交点扎牢。相邻绑扎点的钢丝扣成八字形，以免网片歪斜变形。 4、基础底板采用双层钢筋网时，在上层钢筋网下面应设置钢筋撑脚或混凝 土撑脚，以保证钢筋位置正确，钢筋撑脚下应垫在下片钢筋网上。见图： 钢筋撑脚的形式和尺寸如图，图一所示类型撑脚每隔1m放置1个。其直径选用：当板厚h≦300mm时为8~10mm；当板厚h=300~500,时为12~14mm。当板厚 h>500mm时，选用图二所示撑脚，钢筋直径为16~18mm。沿短向通长布置，间 距以能保证钢筋位置为准。 5、钢筋的弯钩应朝上，不要倒向一边：双层钢筋网的上层钢筋弯钩应朝下。 6、独立柱基础底板钢筋为双向弯曲，其底面短向的钢筋应放在长向钢筋的 上面。
7、现浇柱与基础连接用的插筋，其箍筋尺寸应比柱的箍筋尺寸小一个柱筋 直径，以便连接。箍筋的位置一定要绑扎固定牢靠，以免造成柱轴线偏 移。 8、基础中纵向受力钢筋的混凝土保护层厚度不应小于40mm，当无垫层时， 不应小于70mm。 9、钢筋的连接： ○1受力钢筋的接头宜布置在受力较小处。接头末端至钢筋弯起点的距离不应小于钢筋直径的10倍。 ○2若采用绑扎搭接接头，则接头相邻纵向受力钢筋的绑扎接头宜相互错开。钢筋绑扎接头连接区段的长度为1.3倍搭接长度。凡搭接接头中点位于该区段的搭接接头均属于同一连接区段。位于同一区段内的受拉钢筋搭接接头百分率为25%； ○3当钢筋的直径d>28mm时，不宜采用绑扎接头； ○4纵向受力钢筋采用机械连接接头或焊接接头时，连接区段的长度为35d（d 为纵向受力钢筋的较大值）且不小于500mm。同一连接区段内，纵向受力钢筋的接头面积百分率应符合设计规定，当设计无规定时，应符合下列规定：一、在受拉区不宜大于50%；二、直接承受动力荷载的基础中，不宜采用焊接接头；当采用机械连接接头时，不应大于50%。 10、基础浇筑前，把基础面上预留墙柱插筋扶正理顺，保证插筋位置准确。 11、承台钢筋绑扎前，一定要保证桩基伸出钢筋到承台的锚固长度。 剪力墙钢筋绑扎施工工艺标准 本标准适用于外板内模、外砖内模、全现浇等结构形式的剪力墙钢筋绑扎。工程
施工准备 1材料及主要机具： (1)钢筋：应有出厂合格证，按规定作力学性能复试。当加工过程中发生脆断等特殊情况，还需作化学成分检验。钢筋应无老锈及油污。 (2)铁丝：可采用20～22 号铁丝或镀锌铁丝。铁丝的切断长度要满足使用要求。 (3)控制混凝土保护层用的砼垫块、各种挂钩或撑杆等。 (4)工具：钢筋钩子、撬棍、扳子、绑扎架、钢丝刷子、粉笔、尺子等。 2作业条件： (1)按施工现场平面图规定的位置，将钢筋堆放场地进行清理、平整。准备好垫木，按钢筋绑扎顺序分类堆放，并将锈蚀进行清理。 (2)核对钢筋的级别，型号、形状、尺寸及数量是否与设计图纸及加工配料单相同。 (3)当施工现场地下水位较高时，必须有排水及降水措施。 (4)熟悉图纸，确定钢筋穿插就位顺序，并与有关工种作好配合工作，如支模、管线、防水施工与绑扎钢筋的关系，确定施工方法，作好技术交底工作。(5)根据地下室防水施工方案，底板钢筋绑扎前做完底板下防水层及保护层；支完底板四周模板(或砌完保护墙，做好防水层) 。当地下室外墙防水采用内贴法施工时，在绑扎墙体钢筋之前砌完保护墙，做好防水层及保护层。 二、操作工艺 (1) 、工艺流程：
(2)划钢筋位置线：按图纸标明的钢筋间距，算出底板实际需用的钢筋根数，一般让靠近底板模板边的那根钢筋离模板边为5cm，在底板上弹出钢筋位置线(包括基础梁钢筋位置线)。 (3)绑基础底板及基础梁钢筋 1)按弹出的钢筋位置线，先铺底板下层钢筋。根据底板受力情况，决定下层钢筋哪个方向钢筋在下面，本工程先铺长向钢筋，再铺短向钢筋。 2) 钢筋绑扎时，靠近外围两行的相交点每点都绑扎，中间部分的相交点可相隔交错绑扎，双向受力的钢筋必须将钢筋交叉点全部绑扎。如采用一面顺扣应交错变换方向，也可采用八字扣，但必须保证钢筋不位移。 3)摆放底板混凝土保护层用砼垫块，垫块厚度等于保护层厚度，按每1m 左 右距 离梅花型摆放。如基础底板较厚或基础梁及底板用钢量较大，摆放距离可缩小。 4) 底板如有基础梁，可分段绑扎成型，然后安装就位，或根据梁位置线就地绑扎成型。 5) 基础底板采用双层钢筋时，绑完下层钢筋后，摆放钢筋马凳或钢筋支架(间距以1m 左右一个为宜)，在马凳上摆放纵横两个方向定位钢筋，钢筋上下次序及绑扣方法同底板下层钢筋。 6) 底板钢筋如有绑扎接头时，钢筋搭接长度及搭接位置应符合施工规范要求，钢筋搭接处应用铁丝在中心及两端扎牢。如采用焊接接头，除应按焊接规程规定抽取试样外，接头位置也应符合施工规范的规定。
柱钢筋绑扎施工工艺 柱筋定位卡示意图柱筋定位卡制作实例图 框架柱绑扎柱根部500mm范围内做法 柱钢筋绑扎施工工艺： 1、工艺流程： 柱筋绑扎→安装柱筋定位卡具→平台混凝土浇筑→拆除定位卡具→套柱箍筋→柱主筋连接→绑扎竖向受力筋→画箍筋控制线→箍筋绑扎→保护层设置 2、操作要点： 2.1定位卡具制作：柱钢筋绑扎前，根据柱主筋间距，制作钢筋卡具。卡具固定筋采用φ14钢筋、限位筋采用φ6钢筋，
限位筋间距为柱主筋直径+10mm主筋定位卡制作完成后，可涂刷黄色油漆标示。 2.2柱筋绑扎：根据钢筋位置线校正板面上部预留柱筋，吊装绑扎柱筋。 2.3柱筋定位卡具放置：按照图纸要求绑扎好柱钢筋。绑扎成型后，在距楼面标高上20cm处安装定位卡具，并与主筋绑扎牢固。 2.4套柱箍筋：按图纸要求间距，计算好每根柱箍筋数量，先将箍筋套在下层伸出的搭接筋上，然后立柱子钢筋（包括采用机械连接或电渣压力焊连接施工），当采用绑扎搭接连接时，在搭接长度内，绑扎不少于3个，绑扣要向柱中心。如果柱子主筋采用光圆钢筋搭接时，角部弯钩应与模板成45度，中间钢筋的弯钩应与模板成90度 2.5竖向受力钢筋连接：柱主筋≥Φ16mm采用直螺纹套筒机械连接，Φ12mm、Φ14mm根据现场实际情况考虑电渣压力焊连接或者钢筋绑扎搭接连接，<Φ12mm采用钢筋搭接绑扎连接。绑扎接头的搭接长度应符合设计要求和规定，框架梁、牛腿及柱帽等钢筋，应放在柱的纵向钢筋内侧。 2.6画箍筋间距线：在立好的柱子竖向钢筋上，按图纸要求用粉笔画箍筋间距线，第一根箍筋距离楼面一般为50mm 2.7柱箍筋绑扎： 2.7.1、按已画好的箍筋位置线，将已套好的箍筋往上移动，