Ultra-High-Performance Concrete:
Research, Development and
Application in Europe
Michael Schmidt and Ekkehard Fehling
Synopsis: One of the breakthroughs in concrete technology is ultra-high-performance
2 and a remarkable increase in durability compared even with high-performance concrete. In combination with steel fibres it is now possible to design sustainable filigree, lightweight concrete constructions with or even without additional reinforcement. Wide span girders, bridges, shells and high rise towers are ideal applications widening the range of concrete applications by far. In addition e.g. to some pedestrian bridges heavily trafficked road bridges has been build in France and in the Netherlands. Bridges are already under construction in Germany as well. A wide range of new concrete formulations has been developed to cover an increasing number of applications. Technical recommendations have recently been published in France and in Germany covering material as well as design aspects.
The paper will report on the state of research and application of UHPC in Europe, on material and design aspects of UHPC and will present the state-of-the-art based on an International Symposium on UHPC held in Kassel in 2004.
Keywords: ultra high performance concrete; raw materials; durability; design aspects
Michael Schmidt
born 1947, studied Civil Engineering 1967-1973 at the Technical University of Hanover (Germany), received doctoral degree in 1977 from TU Hanover.
Research Engineer and Senior Specialist at the Research Institute of the German Cement Industry in Düsseldorf 1978-1989. Director of Research and Development of the HeidelbergCement Group 1989-1998. Since 1998 Independent Public Consultant and Court Expert for building materials and cement and gypsum industry in Germany, Europe and Asia. Since 1999 Professor, head of Building Materials Department and Director of Governmental Testing Institute at the University of Kassel.
Ekkehard Fehling
born 1959, studied Civil Engineering 1978 -1983 at the Technical University of Darmstadt (Germany), received doctoral degree in 1990 from TU Darmstadt.
Since 1988 registered Consulting Engineer, since 1997 State licensed Checking Engineer and Professor of Structural Engineering, University of Kassel,
Partner of IBB Fehling+Jungmann, Consulting Engineers, Kassel / Fulda (Germany)
INTRODUCTION
Within the last two decades amazing progress has been made in concrete technology. One of the breakthroughs is the development of ultra-high-performance concrete with a steel like compressive strength of up to 250 N/mm2 and a remarkable increase in durability compared even with high-performance concrete. In combination with a sufficiently high amount of steel fibers it is now possible to design sustainable filigree, lightweight concrete constructions without any additional reinforcement. In prestressed construction elements the prestressing forces may be increased significantly especially if high-strength steel is used. Long span girders, bridges and shells are ideal applications widening the range of concrete applications by far. First practical steps into the future of concrete constructions have already been done. In addition to the well known pedestrian bridge in Sherbrooke in Canada and in South Korea heavily used road bridges has been build or reconstructed in France and in the Netherlands. A long span footbridge is under construction in Germany and the construction of a road bridge used by traffic under severe climatic conditions with intensive salt attacks in winter will start this year to gain more practical experiences with the durability of UHPC.
The growing store of knowledge about the material itself and about the adequate design of constructions with UHPC enabled a technical working groups in France to draw up first technical recommendations primarily focussing on the design (Resplendino 2004, SETRA-AFGC 2002). In Germany a state-of-the-art report has recently been published covering all material and design aspects (DAfStB UHPC 2003).
That means that the concrete itself is steadily optimized and a wide range of new formulations are developed to cover the individual needs of an increasing number of different applications. This paper will report on the state of research and development on UHPC in Europe and about recent applications either already realized, under construction or under development.
HISTORY OF DEVELOPMENT AND APPLICATIONS
In the 1960s concretes with an compressive strength of up to 800 N/mm2 has been developed and produced under specific laboratory conditions. They were compacted under high pressure and thermally treated. In the early 1980s the idea was born to develop fine grained concretes with a very dense and homogeneous cement matrix preventing the development of microcracks within the structure when being loaded. Because of the restricted grain size of less than 1 mm and of the high packing density due to the use of different inert or reactive mineral additions they were called “Reactive Powder Concretes (RPC)” (Bache 1981; Richard and Cheyrezy 1995). Meanwhile there existed a wider range of formulations and the term “Ultra-High-Performance Concrete” or – in short – UHPC was established worldwide for concretes with a minimum compressive strength of 150 N/mm2.
The first commercial applications started around 1980, based on the development of so called D.S.P. mortars in Denmark (Buitelaar 2004). It was primarily used for special applications in the security industry – like vaults, strong rooms and protective defense constructions.
First research and developments aiming at an application of UHPC in constructions started in about 1985. Since then different technical solutions were developed one after the other or parallelly: Heavily (conventionally) reinforced UHPC precast elements for bridge decks; in situ applications for the rehabilitation of deteriorated concrete bridges and industrial floors (Buitelaar 2004) ductile fiber reinforced fine grained “Reactive Powder Concrete” (RPC) like “Ductal” produced by Lafarge in France or Densit produced in Denmark (Acker and Behloul 2004). With or without additional “passive” reinforcement it is used for precast elements and other applications like offshore bucked foundations. In addition, coarse grained UHPC with artificial or natural high strength aggregates were developed e.g. for highly loaded columns and for extremely high-rise buildings (Schmidt et al. 2003). Nowadays an increasing range of formulations is available and can be adjusted to meet the specific requirements of an individual design, construction or architectural approach.
Breakthroughs in application were the very first prestressed hybride pedestrian bridge at Sherbrooke in Canada in 1997, the replacement of steel parts of the cooling tower at Cattenom and two 20.50 and 22.50 m long road bridges used by cars and trucks at Bourg-lès-Valence in France build in 2001 (Hajar et al. 2004), see fig. 1.
For these projects the UHPC was reinforced with about 2.5 to 3 Vol.-% of steel fibers of different shape. The bridges in Bourg-lès-Valence consists of five precast beams which are pre-tensioned. They were placed on site and then joined together with in-situ UHPC. Other footbridges with decks and/or other load bearing components made of fine grained, fiber reinforced UHPC exist in Seoul and in Japan (Acker and Behloul 2004).
A spectacular example of architectural taking advantage of the special benefits of UHPC is the toll-gate of the Millau Viaduct in France, currently under construction. Fig. 2 shows the elegant roof “looking like an enormous twisted sheet of paper”, 98 m long and 28 m wide with a maximum thickness of 85 cm at the center (Resplendino 2004). The structure remembers an aircraft wing. It will be made of match-cast prefabricated 2 m wide segments connected by an internal longitudinal prestressing.
In other European countries UHPC is gaining increasing interest as well. In Germany, as
a result of an extensive research project financed by the government, technical criteria and measures have been already developed to use regionally available raw materials for
fine or coarse grained UHPC, to reduce the cement content and to use fiber mixtures and noncorrosive high strength plastic fibers to control the strength and the ductility depending on the requirements given by an individual design and construction (Fehling et al. 2003; Bornemann et al. 2001; Schmidt et al. 2003; Bornemann and Faber 2004). As a first application, a hybrid bridge is under construction (Fehling et al. 2004) for pedestrian and bicycles with a length of about 135 m and a maximum span of 40 m consisting of precast prestessed chords and precast bridge deck elements made of UHPC with a maximum grain size of 2 mm using local materials. Fig. 3 shows an animation of the bridge, fig. 4 its cross section. The 4.50 x 2.00 x 0.08 m wide bridge deck elements are prestessed transversely. As an additional step of innovation, the load bearing UHPC-elements are glued together without any additional mechanical connection. This means a further step towards an economic material adequate construction technique for UHPC. Inspired by first applications in Canada, South Korea and Europe and by intensive research and development efforts at different universities and of the cement- and construction industry, the DAfStB draw up a state-of-the-art-report on Ultra-High-Performance Concrete (DAfStB UHPC 2003). The DAfStB is part of the German Standardization Organization DIN being responsible for all standards and technical requirements related to the production and application of concrete and giving the rules for the design of concrete structures.
The German state-of-the-art-report covers the technical know-how and the experience with UHPC worldwide published. It covers nearly all applications that exist hitherto – primarily based on commercially available UHPC mixtures – the main principles and the characteristic behavior criteria, durability aspects and the resistance against fire. A second part report refers to the adequate design and construction of structures using UHPC. The report traditionally is a first step towards a reliable technical guideline and a latter standard for UHPC.
In the following some of the material and design aspects covered by the German state-of-the-art-report and by the French design recommendations are presented in more detail.
MATERIALS
Raw materials and material structure
Both the high compressive strength and the improved durability of UHPC are based upon the same four principles
- a very low water-cement-ratio of about 0.20 to 0.25 resulting in a very dense and strong structure of the hydration products and minimizing the capillary pores, which are ductile to prevent brittle failure and to be able to use more or less traditional design approaches against the transport of harmful gases and liquids into and through the concrete,
- a high packing density especially of the fine grains in the binder matrix reducing the
water demand of the fresh mix and increasing the compressive strength – as well as the brittleness of the concrete,
- the use of higher amounts of effective superplastizisers to adjust the workability and – if needed –
- the use of steel or other fibers to increase the tension, the bending tension and the
shear strength and to make the concrete sufficiently ductile.
Fig. 5 shows the packing effect schematically. As a simplified example, fig. 6 shows how the packing density develops when two quartz powders of different fineness (Q 1 and Q 2) are mixed together in different amounts (Geisenhanslüke and Schmidt 2004a). Up to a ratio of about 30 % of the fine and 70% of the “coarse” powder the packing density – defined by the part by volume of particles per unit volume - increases from 48 to 54 Vol.-%. The finer particles by and by fill up the hollow space in between the coarser grains. At the same time, the viscosity of a lime prepared with the powder-mixes at a constant water/fines-ratio of 0.26 decreased from 7500 to less than 5000 mPa s. If the amount of fine particles is further increased beyond the maximum packing density, the rheology of the mix becomes suboptimal again.
To optimize the packing density of UHPC, usually specified quartz powders are used.
Table 1 shows typical compositions of fine and course grained UHPC developed and
used in Germany, fig. 7 the optimized grain size distribution of mix M1Q in table 1 consisting of four different fines. The correlation between the packing density – characterized by the water/fines-ratio of the matrix w/F v – and the compressive strength of heat treated (90°C) and water cured Cylinders (150/300 mm) is shown in fig.8. It is obvious that the packing density not only affects the rheology but also the strength of UHPC as well: at nearly the same water-cement ratio of 0.20 the compressive strength increased by about 25 % when the w/F v-value decreased from 0.53 to 0.40 by adding an pre-calculated amount of another quartz filler with a specified fineness. And table 1 a fig. 8 show that the use of coarser grains help to reduce the cement content and contributes to the compressive strength as well. Further tests showed that autogenous shrinkage and creeping were significantly reduced. The effectiveness of the fibers was reduced as well. This disadvantage could be partly compensated for using longer and stiffer fibers with a length of 17 mm and a diameter of 0.25 mm (Bornemann and Faber 2004).
Due to an European Directive, quartz fillers containing particles with a diameter of less than 5 micron are suspected to cause health problems. This led to intensive efforts to replace those particles by other mineral powders. Positive experiences have been gained with finely ground granulated blast furnace slag, the fine and glassy parts of ground or assorted fly ashes from stone coal power plants and with some high quality stone dusts e.g. produced from basalt. Ultra fine slag particles are even adequate to partly replace microsilica. Common limestone fillers are – as a rule – less beneficial. Research is done to further improve the rheological and the strength performance of UHPC by adding nanotubes (Kowald 2004).
The optimization process can be based on both a theoretical and experimental approaches. Usually the procedure of Okamura (Okamura 1995) is used. In Germany the actual packing density of cements or other powders is tested using the fast and easy Puntke-test (Puntke 2002). A specimen of about 100 g of the powder is filled into a container and slightly compacted. Than water or – for tests on powder mixes containing
cement - a non-reactive liquid of known density is added until the surface is just wet.
The amount of liquid added is a measure for the hollow space and – indirectly – for the packing density.
Testing is time consuming and expensive, especially if the existing information about the powders is lacking and the grain size optimization needs several steps of iteration. Therefore some mathematically based, computer aided calculation procedures have been developed to pre-calculate the best fitting powders and the amounts of each being adequate to reach a maximum packing density (Geisenhanslüke and Schmidt 2004a). Experiences have shown that the results of the existing calculation procedures do not reflect sufficiently the reality when powders of different grain size, grain size distribution, shape and roughness of the surface are mixed in different proportions. In an active research project these procedures are developed further considering the 3-dimensionality of the structure, the shape, the friction of the grains and the so called “particle handicap” schematically shown in figure 9. These effects hinder the individual grains to really reach their theoretical optimum position within the structure of the powder mix.
Strength and deformation behavior
Basis of an adequate, economic and safe design of structures fully or even partly consisting of UHPC elements are reliable reference values characterizing the strength and the deformation behavior under static and dynamic loads. Fiber free fine or coarsely grained UHPC mixtures as shown in table 1are characterized by both, a high compressive strength in between 150 and 250 N/mm2 primarily depending on the water-cement ratio, the volumetric water-to-fines ratio w/F v = w/Σ Vol.(cement+silica+fillers) of the matrix and the grain size of the aggregates as well as a linear elastic deformation up to about 95% of the fracture load. That means UHPC without fibers is a glass like brittle material with a comparatively high modulus of elasticity of 50.000 to 70.000 N/mm2. The typical tension strength of the pure matrix is about 8 N/mm2.
Using steel or other adequate fibers with a sufficiently high modulus of elasticity of more than about 45.000 N/mm2, the compressive strength keeps constant or increases slightly while the tension, the bending tension and the shear strength as well as the ductility are significantly improved. As an example, table 2 (Bornemann et al. 2001; Fehling and Bunje 2004) shows that the bending tension strength of concrete prisms 40/40/160 mm made of fine grained UHPC (Mix M1Q) with 2.5 Vol-% of short steel fibers (length 6 to 9 mm, diameter 0.15 mm) was up to 36N/mm2, that of beams 150/150/700 mm made from the same concrete but without steel fibers was 22 N/mm2 only.
That means if the bending strength of fibered UHPC is introduced into the design of structures it has to be considered that the bending strength primarily depends on the kind and the amount of fibers used, but the orientation and the distribution of the fibers within the matrix and the shape of the specimen used and of the structural element produced with the specific concrete may have a significant influence as well. As a rule, the spread of test results of a specific mixture exceeds that of UHPC mixtures without fibers significantly. Therefore the number of tests done to characterize one specific mix has to be increased to allow a calculation based on the standard deviation (…Characteristic Strength“, 5% fractile). In some active research projects these aspects are further
investigated. Until sufficient knowledge has been gathered and measures have been
developed in order to influence e.g. the fiber orientation by the production process, elements of the designed shape should be placed and tested to validate the theoretically
assumed design criteria.
The same aspects have to be considered regarding the ductility of UHPC. The “amount”
of ductility being necessary to fit the needs depends on the individual design and
construction approach: if the UHPC is assigned for bearing the full tension and bending tension loads without any additional active or passive reinforcement – like in some of the applications e.g. of Ductal – the fiber content has to be sufficiently high to prevent sudden failure even if cracks due to uncalculating stresses and strains appearing locally . In those cases a fiber content of about 2.5 to 3 Vol.-% may give a satisfying compromise regarding workability of the fresh concrete, bending strength and ductility. For other applications, a reduced amount of e.g. 1 Vol.-% of fibers may satisfy the needs, e.g. if slabs, girders or other elements made from UHPC are fully pre-stressed and/or have a passive reinforcement. The fibers are some kind of “transportation reinforcement” and/or allow to utilize the high compressive strength more efficiently due to a higher safety margin to failure. As explained later a combination of passive reinforcement and fibers allow the shear reinforcement of beams to be omitted under bending loads. And in some cases UHPC may be applied even without fibers, e.g. for highly loaded columns or framework constructions consisting of ductile steel pipes filled with UHPC (Tue, Schneider, and Schenk 2004).
In Fig. 10 the effectiveness of steel fibers, high strength non-corrosive Polyvinyl fibers
and a mixture of both, a so called “fiber cocktail” is shown (Bornemann and Faber 2004). Mixes consisting of steel and other suitable fibers of different kind, length and diameter may fulfill the individual needs of a construction more effective by and more economically than fibers of one uniform type.
Durability
The improved resistance of UHPC to all kinds of harmful gases and liquids, to chloride and frost or freezing and thawing attacks is related to the improved density both of the grain structure of the matrix and the much denser contact zone between the matrix and the (coarser) aggregates as well as by the denser structure of the hydration products. Fig.
11 gives an impression of the dense structure.
The porosity of UHPC is characterized by the absence of capillary pores, as one can see from the pore size distribution shown in fig. 12 tested by mercury intrusion. As a result, the extremely high resistance e.g. to chloride diffusion is shown in fig. 13. The resistance to attacks by freezing and salting are significantly improved even when compared with High Performance Concrete, see fig. 14.
In table 3 some characteristic durability indicators are given based on different sources (Schmidt et al. 2003, Teichmann and Schmidt 2004; Resplendino 2004;)
DESIGN ASPECTS
As a rule, the design of concrete structures has to be based on reliable but simplified material reference values, e.g. for the strength and the deformation behavior. For ordinary concrete those approaches are given in the relevant standards. For UHPC two similar approaches have been developed, one established by AFGC/SETRA in France in 2002 (SETRA-AFCG 2002) and one as part of the state-of-the-art report of the DAfStB in Germany in 2003 (DAfStB UHPC 2003). They both consider the fact, that as a rule the material properties of fiber reinforced UHPC show a significant higher deviation due to an inhomogenious distibution and orientation of the fibres in the matrix (Bernier and Behloul 1996).
The French recommendations consist of three parts:
– the first part gives specifications on the mechanical performance to be obtained and recommendations for characterizing UHPC including checks of finished products and of the concrete being produced,
– the second part deals with the design and analysis of structures made with fibre reinforced, non-prestressed and/or non-reinforced UHPC-elements and
– a third part dealing with the durability of UHPC.
An important part deals with the behavior of fiber containing UHPC under tensile loading. As fig. 15 (Resplendino 2004; SETRA-AFCG) shows, the stress-strain relation is characterized by an elastic stage limited by the tensile strength of the cement matrix f tj and a post cracking stage characterized by the tensile strength of the composite material reached by fiber action.
Using characterization tests depending on the type of structure studied (thin or thick slabs, beams, shells) and on the kind of load (direct or flexural tensile) the recommendations give the transfer factors to come from the test results to an “intrinsic” curve for tensile behavior independent of the size of the specimen and the kind of test used. In addition, a reduction factor is given to take into account the effect placement methods has on the real strength values to be obtained in a specific structural element. The French design methods proposed are in accordance with the French codes for pre-stressed or reinforced concrete BAEL 91 and BPEL 91 based on semi-probabilistic limit state values. Supplementary to the design codes the recommendations contain specificities concerning UHPC like the strength provided by fibers which allows the design of structures without any conventional reinforcement.
For normal stress verification, the French recommendations use the AFREM-BFM method which concerns fiber concrete, and use a stress-crack width constitutive law σ = f(w). Moreover the characteristic length l c is introduced, to go from crack width w to strain ε:
ε = f tj / E ij + w/ I c,
The value of I c depends on the sections area. The analysis for standard sections is based on the assumptions that plane sections remain plane and the concrete behavior law follows fig. 16. The limit stresses at the SLS are the same as for a reinforced or
prestressed structure: 0.3 mm for normal cracking, 0.2 mm for detrimental and 0.1 mm for highly detrimental cracking.
For calculation of the Serviceability Limit State (SLS), a somewhat more simplified stress strain relationship as shown in Fig. 17 may be used according to the recommendations given by (DAfStb UHPC 2003).
The German report describes a standard test procedure as shown in fig. 18 to evaluate the load-deformation behavior of UHPC under bending loads in order to determine a stress strain relationship.
Fig. 19 shows the result of such a test. To transform it into a stress-strain relation, the stresses at a crack width of 0.5 and 3.5 mm are being considered.
Fig. 20 shows the stress-strain curves calculated according to this proposal. The stresses at the significant points of the curve are determined from the equations
σ2.0 – 3.5 ‰ = f ctk0.5 ? 0.37 σ25‰ = β ?f ctk3,5.
The factor β as well as the factor 0.37 have been established by recalculating test results. As for ordinary concrete, the factor β depends on the relation f ctk,3.5 / f ctk,0.5. It can be taken from fig. 21.
Normally a strain limit of 25‰ is adequate. But re-calculations of test results already showed that for a ratio f 3.5 / f 0.5 < 0,5 the design may fall short of the necessary safety margin. In fig. 21 the reduced strain for f 3.5/f 0.5 < - 0.5 is characterized by the marked curve.
For the design in the Ultimate Limit State, the stress strain law according to DIN 1045-1 is proposed. It is defined by the following equation (1):
c c20≥ε≥ε (1)
The exponent n in Eq. 1 can be taken from table 4. This enables a transition to the rules for High Strength Concrete (HSC/HPC). For UHPC 210 and higher strength classes, hence, a linear relationship results. Furthermore, for UHPC without fibers or insufficient confinement,εc2 = εc2u shall be assumed in order to account for the brittleness in such cases.
The design value of the compressive strength follows Eq. 2.
'
85,0c
c ck
cd f f γγ??
= (2)
with
c γ partial safety coefficient according to table 2 in DIN 1045-1
'c γ
additional partial safety factor taking into account the sensibility for deviations The strain at the maximum stress can be assumed to be 2,2‰ starting with strength class C 100/115 acc. to EN 206. For the special permit required in Germany for structures built of new materials, different values may be proposed by the obligatory expertise. For UHPC with fibers or sufficient confinement, a plastic branch until the strain f
c2u ε can be used in order to account for the improved ductility. The value of f
c2u ε can be determined in such a way that the capacity in bending is adjusted to the bending capacity obtained from a stress strain law with a descending branch and assuming yielding of steel in the tension zone. However, since the influence of the descending branch of the stress strain relationship is of minor importance, the additional strain (length of the horizontal branch in the stress strain diagram) can be assumed to be quasi linear.
Shear and Torsion
In order to determine the reinforcement possibly required for shear loading, the resistance due to the concrete, the shear reinforcement (e.g. stirrups) and the fibers can be added according to the SETRA–AFGC regulations:
V u = V Rb + V a + V f
(3) with: V Rb
= shear resistance of concrete section V a
= shear resistance to discrete reinforcement
V f
= shear resistance due to fibers
(4)
with: σp
K w lim = max(w u ; 0,3 mm), where w u = l c ? εu and l c ... characteristic length σ(w) = characteristic post cracking tensile resistance for crack width w
(according to tests)
S = area of fiber action: S = 0,9 b 0 ? d bzw. b 0 ? z for rectangular and T-shape sections S = 0,8 ? (0,9 d)2 bzw. 0,8 z 2 for circular sections
γbf
= particular safety coefficient for fiber concrete in tension
βu = angle of compression struts
Similar concepts have been proposed in the German design guidelines for steel fiber
concrete of DAfStb. Experimental results obtained in Germany (Fehling and Bunje 2003) lead to similar results. However, additional research is required for the behavior of
UHPC subject to shear and torsion loads.
Bond of Reinforcement
Due to the high compressive strength and the high density, UHPC enables very high bond stresses. For smooth fibers (l = 13 mm, ? = 0.15/0.2 mm), Behloul (1996) reports a value of f b=11.5 MPa for BPR (DUCTAL). For prestressing wires and strands, the maximum bond stress depends on the concrete cover (see Figure 24)
For ribbed reinforcing bars, very high bond stresses in the range of 40 to 70 MPa have been reported. (Wei?e 2003, Reineck and Greiner 2004), see fig. 25. In tests on rebars with 10 mm diameter splitting failure in the concrete cover was observed for a cover less than 25 mm. Due to the high bond stresses, the bond length in the standard RILEM pull-out specimen has to be reduced to 2 ? instead of 5 ? (see Figure 26). Otherwise, no pull-out would be feasible before the yielding of steel.
Fatigue Resistance
For fatigue loading under compression, tests performed at the University of Kassel for UHPC have shown a rather good behavior. S-N-curves for UHPC and NSC are compared in Figure 27. The (relative) stress range of UHPFRC for a large number of load reversals (> 2 million) is similarly high as for NSC, while the absolute stress level is much higher than for NSC. Thus, it can be said, that in contrast to other high strength materials, the high strength of UHPC with fibers does not lead to disadvantages with regard to fatigue (Fehling et al. 2003; Schmidt et al. 2003) Currently, fatigue tests in bending are conducted at Delft University of Technology.
Fire Resistance
Due to the extremely high density of UHPC, high water pressure can arise when UHPC is exposed to fire. This can lead to deterioration of the concrete structure. The problem can be overcome by the use of fibers, e. g. polypropylene fibers. One effect of the fibers is that they create capillary pores due to melting and burning. Furthermore, around the fibers transition zones to the cement matrix are formed. By this, the existing transition zones between aggregates and matrix are interlinked so that the permeability increases and the steam pressure is reduced. Experiments have shown the effectiveness of adding polypropylene fibers (Diederichs 1999; Dehn and K?nig 2002; Bornemann, Schmidt, and Vellmer 2002). Another problem is associated with the anomaly of quartziferous compounds with respect to the volumetric expansion occurring at 573 °C due to the change of crystal phases. Good results could be obtained by replacing quartz with basalt.
SUMMARY AND CONCLUSIONS
Within the last two decades amazing progress has been made in concrete technology. One of the breakthroughs is the develeopment of ultra-high-performance concrete with its steel like compressive strength and a remarkable increase in durability. UHPC is an high-tech material following new technological rules regarding its composition, its production, the mechanical behaviour as well as regarding design and construction of structures. Meanwhile a great store of knowledge about the material and about the adequate design and construction of structures with UHPC exist. Provisional Technical Recommendations have been published in France and in Germany. Some first spectacular applications in Canada, Europe and Asia have proven the assumed benefits of the new technology regarding costs, sustainabilty and service life. A wide range of different formulations are developed worldwide to meet the individual needs of the increasing number of different applications. Nevertheless there is a need for further research and development to close existing gaps of knowledge and to come to a widespread “regular” application based on comprehensive technical regulations.
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Fehling, E.; Schmidt, M.; Teichmann, T. and Bunje, K., 2003, Entwicklung, Dauerhaftigkeit und Berechnung Ultra-Hochfester Betone (UHPC), Research Report, University of Kassel, 185 pp.
Fehling, E.; Bunje, K.; Leutbecher, T., …Bemessung für Biegung und Querkraft bei Bauteilen aus UHFB,“ in: Ultrahochfester Beton, Innovationen im Bauwesen, Beitr?ge aus Praxis und Wissenschaft, Eds. K?nig, G.; Holschemacher, K.; Dehn, F., Bauwerk-Verlag, 2003.
Geisenhanslüke, C. and Schmidt, M., 2004a, …Modeling and Calculation of High Density Packing of Cement and Fillers in UHPC,” Proceedings of the International Symposium on Ultra High Performance Concrete, Kassel University Press, Kassel, Germany, pp 303-312.
Geisenhanslüke, C. and Schmidt, M., 2004b, …Optimierung der Packungsdichte des Feinstkorns bei Ultra-Hochleistungs- und Selbstverdichtendem Beton”, beton, to be published.
Hajar, Z.; Simon, A.; Lecointre, D.; and Petitjean, J., 2004, Design and Construction of the world first Ultra-High Performance road bridges,” Proceedings of the International Symposium on Ultra High Performance Concrete, Kassel University Press, Kassel, Germany, pp 39-48.
Kowald, T., 2004, …Influence of surface modified Carbon Nanotubes on Ultra-High Performance Concrete,” Proceedings of the International Symposium on Ultra High Performance Concrete, Kassel University Press, Kassel, Germany, pp 195-202.
Ma, J; Schneider, H., 2003, “Creep of ultra-high performance concrete under compressive stresses,” Leipzig Annual Civil Engineering Report, No.8, 2003.
Ma, J.; Dehn, F.; K?nig G., 2004, “Autogenous shrinkage of self-compacting ultra-high performance concrete,” Proceeding International Conference on Advances in Concrete and Structures, Mai, 2004, Xuzhou, P.R. China.
Okamura, H.; Kazumasa, O.: Mix Design of Self-Compacting Concrete. Proc. of JSCE 25 (1995); S. 107-120.
Puntke, W., 2002, “Wasseranspruch von feinen Kornhaufwerken,” beton, Vol. 52, No. 5, pp. 242-248.
Racky, P., 2004, …Cost-effectiveness and sustainability of UHPC,” Proceedings of the International Symposium on Ultra High Performance Concrete, Kassel University Press, pp 797-806.
Reineck, K.-H., Greiner, S., 2004, …Dichte Hei?wasser-W?rmespeicher aus ultrahochfestem Faserfeinkornbeton,“ Research report BMBF-Project 0329606 V. Institut für Leichtbau Entwerfen und Konstruieren, University of Stuttgart, 2004. Resplendino, J., 2004, “First Recommendations for Ultra-High-Performance Concretes and examples of Application,” Proceedings of the International Symposium on Ultra High Performance Concrete, Kassel University Press, Kassel, Germany, pp 79-90. Richard, P. and Cheyrezy, M., 1995, “Composition of Reactive Powder Concretes,” Cement and Concrete Research, Vol. 25, No. 7, pp. 1501-1511.
Schmidt, M.; Fehling, E.; Teichmann, T.; Bunje, K.; and Bornemann, R., 2003, “Ultra-high performance concrete: Perspective for the precast concrete industry,” Beton und Fertigteil-Technik, 2003, No. 3, pp. 16-29.
Schneider, U.; Horvath, J.; Dehn, F., 2002, Faserbewehrte ultrahochfeste Betone,“ Faserbeton - Innovationen im Bauwesen, Eds. K?nig, G.; Holschemacher, K.; Dehn, F., Bauwerk-Verlag, Berlin 2002.
Thibeaux T. and Tanner, T.A, 2002, “Construction des premiers ponts francais en beton fiber a ultra hautes performance/construction of the first french road bridges made of UHPC,” La technique francaise du Beton, AFGC, the first fib congress 2002, Osaka 2002.
Tue, N.V.; Küchler, H.; Schenk, G., Jürgen, R., 2004, …Application of UHPC Tubes filled Tubes in Buildings and Bridges “, Proceedings of the International Symposium on Ultra High Performance Concrete, Kassel University Press, Kassel, Germany, pp 807-818.
Wei?e, D., 2003, Verbundverhalten der Bewehrung in UHFB. S. 199-214 in: Ultrahochfester Beton. Innovationen im Bauwesen. Beitr?ge aus Praxis und Wissenschaft. ed.: K?nig, G.; Holschemacher, K.; Dehn, F. Bauwerk Verlag GmbH. Berlin, November 2003
French Standards, Codes and Recommendations
AFREM – BFM, 1995, Recommandations sur les methodes de dimensionnement, les
essais de characterisation, de convenance et de contr?le. Elements de structures fonctionnant comme des poutres, dec. 1995.
BAEL 91 revisé 99, Regles techniques de conception et de calcul des ouvrages et constructions an beton arme suivante la methode des etats limites, Fasc. 62 (Titre premier, section 1 du CCTG, april 1999.
BPEL 91 revisé 99, Regles techniques de conception et de calcul des ouvrages et constructions en beton precontraint suivante la methode des etats limites, Fasc. 62 (Titre premier, section 2 du CCTG), april 1999.
SETRA – AFGC Ultra High Performance Fiber-Reinforced Concretes. Interim Recommendations, AFGC Groupe de travail BFUP, ed. January 2002.
German Standards and Guidelines
DAfStB Richtlinie Stahlfaserbeton/Technical Guidelines for Steel Fiber Reinforces Concrete, part 1-4,“ Deutscher Ausschuss für Stahlbeton im DIN Deutsches Institut für Normung/German Assossiation for Reinforced Concrete within DIN, German Institute for Standardisation, Berlin, 10th draft, 2003.
DIN 1045-1 (07.2001) Concrete, reinforced and prestressed concrete structures – Part 1: Design.
DIN 1045-1 (07.2001) Concrete, reinforced and prestressed concrete structures – Part 2: Concrete – Specification, properties, production and conformity – Application rules for DIN EN 206-1.
Figure 2--Roof of the Millau toll-gate (Resplendino 2004). Figure 3--Hybrid bridge in Kassel (Fehling et al. 2004)
Figure 5--Packing effect schematical
45%
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amount of filler Q1 [% b.m.]
p a c k i n g d e n s i t y , c a l c u l a t e d [% b .v .]
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Figure 6--Influence of the packing density on the rheology of UHPC (Geisenhanslüke and Schmidt 2004a)
130
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Figure 8--Compressive strength vs. water/fines- ratio of the cement matrix.
Figure 9--“Particle handicap” influencing the packing density (Geisenhanslüke and Schmidt 2004b)
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，