Reynolds, Charles E. (Charles Edwani). Reinforced concrete designer's handbook/Charles EReynolds and James C. Steedman. 10th ed. p. cm. Bibliography:p. Records 61 - of Handbook, Eleventh Edition by Charles E. Reynolds, James C. Steedman, Anthony J. Threlfall Steedman and Anthony J. Threlfall pdf. Reynolds's Reinforced Concrete Designer's Handbook Designer's Handbook, Eleventh Edition By Charles E. Reynolds PDF [BOOK].
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Reinforced Concrete Designers Handbook 11th Edition Reynolds Steedman - Ebook download as PDF File .pdf) or read book online.:). Eleventh Edition by Charles E. Reynolds and James C. Handbook Eleventh Edition Pdf An "Reinforced Concrete Designer's Handbook" by Charles E. Home · Reinforced Concrete Designers Handbook 11th Edition Reynolds Steedman. Reinforced Concrete Designers Handbook 11th Edition.
The imposed loads given in Table 2. The snow load on the roof is determined by multiplying the estimated snow load on the ground at the site location and altitude the site snow load by an appropriate snow load shape coefficient. The main loading conditions to be considered are: aJ a uniformly distributed snow load over the entire roof, likely to occur when snow falls with little or no wind; b a redistributed or unevenly deposited snow load, likely to OCcur in windy conditions. For flat or mono-pitch roofs, it is sufficient to consider the single load case reSUlting from a uniform layer of snow, as gIVen in Table 2. For other roof shapes and for the effects of local drifting of snow behind parapets, reference should be IIladoto BS Part 3 for further information. Minimum loads are given for roofs with no access other than thatnecessary for cleaning and maintenance and for roofs Where access is provided. The effect of acceleration must be considered in addition to the static loads when calculating loads due to lifts and similar machinery.
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site Handbooi Stream millions of songs. Rammed Earth Construction Christopher Beckett. Summary This classic and essential work has been thoroughly revised and designet in line with the requirements of new codes and standards which have been introduced in recent years, including the new Eurocode as well as up-to-date British Standards. Considerations Affecting Design Details.
Appendix: Mathematical Formulae and Data. Design criteria, safety factors and loads 3. Material properties 4. Structural analysis 5.
Design of structural members 6. Buildings, bridges and containment structures 7. Foundations, ground slabs and earth-retaining structures Part 2: Loads, Materials and Structures 8. Pressures due to retained materials Concrete and reinforcement Cantilevers and single span beams Continuous beams Framed structures Shear wall structures Containment structures Foundations and retaining walls Miscellaneous structures and details The more factors allowed for in the calculations the higher may be the strengths or stresses, and vice versa.
There are possibly other factors to be If the magnitude of a load, or other factor, is not known precisely it is advisable to study the effects of the probable taken into account in any particular case, such as the use of available steel forms of standard sizes.
In the United largest and smallest values of the factor and provide Kingdom economy generally results from the use of simple formwork even if this requires more concrete compared with resistance for the most adverse case.
Some of the factors which may have to be considered are whether less concrete of a rich mix is cheaper than a greater volume of a leaner concrete; whether the cost of higherpriced bars of long lengths will offset the cosf of the extra weight used in lapping shorter and cheaper bars; whether, consistent with efficient detailing, a few bars of large diameter can replace a larger number of haTs of smaller diameter; whether the extra cost of rapid-hardening cement justifies the saving made by using the forms a greater number of times; or whether uniformity in the sizes of members saves in formwork what it may cost in extra concrete.
There is also a wider aspect of economy, such as whether the anticipated life and use of a proposed structure warrant the use of a higher or lower factor of safety than is usual; whether the extra cost of an expensive type of construction is warranted by the improvement in facilities; or whether the initial cost of a construction of high quality with little or no maintainance cost is more economical than less costly construction combined with the expense of maintenance.
The working of a contract and the experience of the contractor, the position of the site and the nature of the available materials, and even the method of measuring the quantities, together with numerous other points, all have their effect, consciously or not, on the designer's attitude towards a contract.
So many and varied are the factors to be considered that only experience and the study of the trend of design can give any reliable guidance. Attempts to determine the most economical proportions for a given member based only on inclusive prices of concrete, reinforcement and formwork are often misleading. It is nevertheless possible to lay down certain principles.
For equal weights, combined material and labour costs for reinforcement bars of small diameter are greater than. The lower the cement content the cheaper the concrete but, other factors being equal, the lower is the strength and durability of the concrete.
Taking compressive strength and the compressive stress in the concrete is the maximum permissible stress and the tensile stress in the steel is that which gives the minimum combined weight of tension and compression reinforcement.
When the cost of mild steel is high in relation to that of concrete, the most economical slab is that in which the proportion of tension reinforcement is well below the so-called 'economic' proportion.
The economic proportion is that at which the maximum resistance moments due to the steel and concrete, when each is considered separately, are equal. T-beams are cheaper if the but here again the increase rib is made as deep as in headroom that results from reducing the depth may offset the small extra cost of a shallower beam. It is rarely economical to design a T-beam to achieve the maximum permissible resistance from the concrete.
Inclined bars are more economical than links for resisting shearing force, and this may be true even if bars have to be inserted specially for this purpose. Formwork is obviously cheaper if angles are right angles, if surfaces are plane, and if there is some repetition of use.
Therefore splays and chamfers are omitted unless structurally necessary or essential to durability. Wherever possible architectural features in work cast in situ should be formed in straight lines. When the cost of formwork is considered in conjunction with the cost of concrete and reinforcement, the introduction of complications in the formwork may sometimes lead to more economical construction; for example, large continuous beams may be more economical if they are haunched at the supports.
Cylindrical tanks are cheaper than rectangular tanks of the same capacity if many uses are obtained from one set of forms. In some cases domed roofs and tank bottoms are more economical than flat beam-and-slab construction, although the unit cost of the formwork may be doubled for curved work. When formwork can be used several times without alteration, the employment of steel forms should be considered and, because steel is less adaptable than wood, the shape and dimensions of the work may have to be determined to suit.
Generally, steel forms for beam-and-slab or column construction are cheaper than cost into account, a concrete rich in cement is more timber formwork if twenty or more uses can be assured, but economical than a leaner concrete.
In beams and slabs, for circular work half this number of uses may warrant the however, where much of the concrete is in tension and use of steel. Timber formwork for slabs, walls, beams, column therefore neglected in the calculations, it is less costly to use sides etc.
In columns, where all the six to eight times before the cost of repair equals the cost of new formwork. Beam-bottom boards can be used at least concrete is in compression, the use of a rich concrete is more economical, since besides the concrete being more efficient, there is a saving in formwork resulting from the reduction in the size of the column.
The use of steel in compression is always uneconomical when the cost of a single member is being considered, but advantages resulting from reducing the depth of beams and the size of columns may offset the extra cost of the individual twice as often.
Precast concrete construction usually reduces consider- ably the amount of formwork and temporary supports required, and the moulds can generally be used very many more times than can site formwork.
In some cases, however, the loss of structural rigidity due to the absence of monolithic construction may offset the economy otherwise resulting member. When designing for the ultimate limit-state the from precast construction. To obtain the economical most economical doubly-reinforced beam is that in which advantage of precasting and the structural advantage of in the total combined weight of tension and compression steel situ casting, it is often convenient to combine both types of when the depth of the in the same structure.
This In many cases the most economical design can be neutral axis is as great as possible without reducing the design strength in the tension steel see section 5. With determined only by comparing the approximate costs of permissible-working-stress design the most economical different designs.
Drawings and is practically the only way of determining, say, when a simple cantilevered retaining wall ceases to be more 5 All principal dimensions such as the distance between columns and overall and intermediate heights should be economical than one with counterforts; when a solid-slab bridge is more economical than a slab-and-girder bridge; or when a cylindrical container is cheaper than a rectangular container. Although it is usually more economical in floor construction for the main beams to be of shorter span than indicated, in addition to any clearances, exceptional loads and other special requirements.
A convenient scale for most general arrangement drawings is I: In the case of flat-slab construction, it may be worth while considering alternative spacings of the columns. An essential aspect of economical design is an appreciation of the possibilities of materials other than concrete. The The working drawings should be large-scale details of the members shown on the general drawing. A suitable scale is 1: Just as there is no structural reason for facing a reinforced concrete bridge with stone, so there is no economic gain in casting in situ a reinforced concrete wall panel if a brick wall is cheaper and will serve the same shown for the details of the reinforcement in slabs, beams, columns, frames and walls, since it is not advisable to show the reinforcement for more than one such member in a single although a larger scale may be necessary for complex structures.
It is often of great assistance if the general drawing I 10 or I in to I ft. Separate sections. Other common cases of the consideration of view. An indication should be given, however, of the different materials are the installation of timber or steel reinforcement in slabs and columns in relation to the bunkers when only a short life is required, the erection of light steel framing for the superstructures of industrial buildings, and the provision of pitched steel roof trusses.
Included in such economic comparisons should be such factors as fire resistance, deterioration, depreciation, insurance, appearance and speed of construction, and structural considerations such as the weight on the foundations, convenience of construction and the scarcity or otherwise of materials. The following observations can be taken as a guide when no precedent or other guidance is available. In this respect, practice in the UK should comply with the report published jointly by the Concrete Society and the Institution of Structural Engineers and dealing with, among other matters, detailing of reinforced concrete structures.
The recommendations given in the following do not necessarilj conform entirely with the proposals in the report ref. A principal factor is to ensure that, on all drawings for any one contract, the same conventions are adopted and uniformity of appearance and size is achieved, thereby making the drawings easier to read. The scale employed should be commensurate with the amount of detail to be shown. Some suggested scales for drawings with metric dimensions and suitable equivalent scales for those in imperial dimensions are as follbws.
In the preliminary stages. Later this, or a similar drawing, is utilized as a key to the working drawings, and should show precisely such particulars as the setting-out of the structure in relation to adjacent buildings or other permanent works, and the level of, say, the ground floor in relation to a datum.
Sections through beams and columns showing the detailed arrangement of the bars should be placed as closely as possible to the position where the section is taken. In reinforced concrete details, it may be preferable for the outline of the concrete to be indicated by a thin line and to show the reinforcement by a bold line.
Wherever clearness is not otherwised sacrificed, the line representing the bar should be placed in the exact position intended for the bar, proper allowance being made for the amount of cover. Thus the reinforcement as shown on the drawing will represent as nearly as possible the appearance of the reinforcement as fixed on the site, all hooks and bends being drawn to scale.
The alternative to the foregoing method that is frequently adopted is for the concrete to be indicated by a bold line and the reinforcement by a thin line; this method, which is not recommended in the report previously mentioned, has some advantages but also has some drawbacks. The dimensions given on the drawing should be arranged so that the primary dimensions connect column and beam centres or other leading setting-out lines, and so that secondary dimensions give the detailed sizes with reference to the main setting-out lines.
The dimensions on working drawings should also be given in such a way that the carpenters making the formwork have as little calculation to do as possible. Thus, generally, the distances between breaks in any surface should be dimensioned. Disjointed dimensions should be avoided by combining as much information as possible in a single line of dimensions, It is of some importance to show on detail drawings the positions of bolts and other fitments that may be required to be embedded in the concrete, and of holes etc.
If such are shown on the same drawings as the reinforcement, there is less likelihood of conflicting information being depicted.
This proposal may be of limited usefulness in buildings but is of considerable importance in industrial structures. Consistency in this makes it easier to understand complicated details. If the bar- in meaning. Notes which apply to all working drawings can placed as closely as possible to the view or detail concerned, shown on a detail drawings should be described on the latter, bending schedule is not given on a detail drawing, a reference should be made to the page numbers of the bar-bending Any notes on general or detailed drawings should be schedule relating to the details on that drawing.
If a group of notes is lengthy Although the proportions of the concrete, the cover of there is a that individual notes will be read only concrete over the reinforcement, and similar information are cursorily and an important requirement be overlooked. Chapter 2 Safety factors, loads and pressures 2. On the one hand, calculations are undertaken to find the strength of a section of a member at which it becomes unserviceable, perhaps due to failure is imminent, rather than the concrete crushing, which may happen unexpectedly and explosively a greater factor of safety is employed to evaluate the maximum permissible stress in concrete than that used to determine the maximum permissible stress in the reinforcement.
Calculations 2. The ratio of the resistance of the section to the moment or force causing unserviceability at that section may be termed the factqr of safety of the section concerned. However, the determination of the overall global factor of safety of a complete structure is usually somewhat more complex, since this represents the ratio of the greatest load that a structure can carry to the actual loading for which it has been designed.
Now, although the moment of resistance of a reinforced concrete section can be calculated with reasonable accuracy, the bending moments and forces acting on a structure as failure is approached are far more difficult to determine since under such conditions a great deal of redistribution of forces occurs. For example, in a continuous beam the overstressing at one point, say at a support, may be relieved by a reserve of strength that exists elsewhere, say at midspan.
Thus the distribution of bending moment at failure may be quite different from that which occurs under service conditions. To obviate this shortcoming, the load-factor method of design was introduced into CP1 Theoretically, this method involves the analysis of sections at failure, the actual strength of a section being related to the actual load causing failure, with the latter being determined by 'factoring' the design load.
However, to avoid possible confusion caused by the need to employ both service and ultimate loads and stresses for design in the same document, as would be necessary since modular-ratio theory was to continue to be used, the load-factor method was introduced in CP1 14 in terms of working stresses and loads, by modifying the method accordingly.
In elasticstress i. With this method, the design of each individual member or section of a member must satisfy two separate criteria: The principal criteria relating to serviceability are the prevention of excessive deflection, excessive 2. In addition, to ensure that if any structure and in special circumstances other limit-state failure does occur it is in a 'desirable' form e.
Safety factors, loads and pressures 8 To ensure acceptable compliance with these limit-states, various partial factors of safety are employed in limit-state their design by methods based on permissible working stresses.
The particular values selected for these factors depend on the accuracy known for the load or strength to which the factor is being applied, the seriousness of the Note When carrying out any calculation, it is most important that the designer is absolutely clear as to the consequences that might follow if excessive loading or stress occurs, and so on.
Some details of the various partial factors of safety specified in BS8I 10 and CPI 10 and their applica- condition he is investigating. This is of especial importance when he is using values obtained from tables or graphs such as those given in Part II of this book.
For example, tabulated values for the strength of a section at the ultimate limit-state must never be used to satisfy the requirements obtained by carrying out a serviceability analysis, i.
It will be seen that at each limit-state considered, two partial safety factors are involved. The characteristic loads are multiplied by a partial safety factor for loads Yf to obtain the design loads, thus enabling calculation of the bending moments and shearing forces for which the member is to be designed.
Thus if the characteristic loads are multiplied by the value of y1 corresponding to the ultimate limit-state, the moments and forces subsequently determined will represent those occurring at failure, and the sections must be designed accordingly. Similarly, if the value of y1 corresponding to the limit-state of serviceability is used, the moments and forces under service loads will be obtained.
In a similar manner, characteristic strengths of materials bending moments and shearing forces due to unfactored characteristic loads.
As explained above, a design load is calculated by multiplying the Ym characteristic load by the appropriate partial factor of safety According to the Code Handbook a characterfor loads istic load is, by definition, 'that value of load which has an accepted probability of its not being exceeded during the life of the structure' and ideally should be evaluated from the avoidance of excessive cracking or deflection may be undertaken, and suitable procedures are outlined to undertake such a full analysis for every section would be too time-consuming and arduous, as well as being the mean load with a standard deviation from this value.
BS8I 10 states that for design purposes the loads set out in and CP3: Part 2 may be BS Part considered as characteristic dead, imposed and wind loads. Thus the values given in Tables 2—8 may be considered to be characteristic loads for the purposes of limit-state used are divided by a partial safety factor for materials to obtain appropriate design strengths for each material.
Although serviceability limit-state calculations to ensure Therefore BS8 and CPI 10 specify certain limits relating to bar spacing, slenderness etc.
Should a proposed design fall outside these tabulated limiting values, however, the engineer may still be able to show that his design meets the Code requirements regarding serviceability by producing detailed calculations to validate his claim. Thus the 1 calculations. In the case of wind loading, in CP3: Part 2 a multiplying factor S3 has been incorporated in the expression used to determine the characteristic wind load to take account of the probability of the basic wind speed being exceeded during the life of the structure.
Data for calculating dead loads are given in unfactored dead and imposed loads, as is undertaken with modular-ratio and load-factor design, may conveniently be Tables 2,3 and 4: Although imprecise, this concept may be useful in appreciat- ing the relationship between limit-state and other design methods, especially as permissible-working-stress design is likely to continue to be used for certain types of structures and structural members e.
In view of the continuing usefulness of permissible-working-stress design, which has been shown by the experience of many years to result in the production of safe and economical designs for widely diverse types of structure, most of the design data given elsewhere in this book, particularly in those chapters dealing with structures other than building frames and similar components, are related to the analysis of structures Lnder service loads and 2.
The accurate assessment of the actual and probable loads is an important factor in the production of economical and efficient structures. Some imposed loads, such as the pressures and weights due to contained liquids, can be determined exactly; less definite, but capable of being calculated with reasonable accuracy, are the pressures of retained granular materials. Other loads, such as those on floors, roofs and bridges, are generally specified at characteristic values.
Wind forces are much less definite, and marine forces are among the least determinable. Imposed loads 9 2. The loads given in Tables 6 and 7 are based on BS Part I which has replaced CP3: Part 1.
A slab must be designed to carry either of these loads, whichever produces the most adverse conditions. The concentrated load need not be considered in the case of solid slabs or other slabs capable of effectively distributing loads laterally. Beams are designed for the appropriate uniformly distributed load, but beams spaced at not more than I m or 40 in centres are designed as slabs.
The loads on floors of warehouses and garages are dealt with in sections 2. In all cases of floors in buildings it is advisable, and in some localities it is compulsory, to affix a notice indicating the imposed load for which the floor is designed. The weights of any machines or similar, fixtures should be allowed for if they are likely to cause effects more adverse than the specified minimum imposed load. Any reduction in the specified imposed load due to multiple storeys or to floors of large area should not be applied to the gross weight of the machines or fixtures.
The approximate weights of some machinery such as conveyors and screening plants are given in Table The effects on the supporting structure of passenger and goods lifts are given in Table 12 and the forces in collieTry pit-head frames are given in section 9.
The support of heavy safes requires special consideration, and the floors should be designed not only for the safe in its permanent position but also for the condition when the safe is being moved into position, unless temporary props or other means of relief are provided during installation. Computing and other heavy office equipment should also be considered specially.
The forces specified in BS Part 1 are given in Table 7 for parapets on various structures in terms of force per unit length. Part 2 specifies the horizontal force on the parapet of a bridge supporting a footway or cycle track to be 1. Freshly fallen snow weighs about 0. For sloping roofs the snow load decreases with an increase in the slope.
The possibility of converting a flat roof to such purposes or of using it as a floor in the future should also be anticipated. A roof is considered to be a floor. These requirements are in accordance with the Code. If the load on a beam is reduced because of the large area supported, the columns structural members subjected to continuous vibration due or other supporting members may be designed either for to machinery, crushing plant, centrifugal driers and the like, this reduced load or for the reduction due to the number an allowance for dynamic effect can be made by reducing of storeys.
However, for the guidance of designers, notes regarding bridge loading etc. Road bridges. These altered, for example, the equivalent HA loading for short loaded lengths, the wheel dimensions for HB loading etc.
For details reference should be made to the various memoranda. These modifications are embodied in BS, The basic imposed load to be considered HA loading comprises a uniformly distributed load, the intensity of which depends on the 'loaded length' i.