Basic requirements of building as a whole

Basic requirements of building as a whole

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  Unit no. 2 1.Basic requirement of building s whole Mr. K. R. Patil Assistant Professor D. Y. Patil College of Engineering & Technology, Kolhapur
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  • Introduction: • Abuilding structure should be satisfy the basic requirements in design & performance. 1. The structure must have an adequate factor of safety to support additional loading. 2. It must have sufficient stiffness so that its distortion does not observed by eye or does not reduces efficiency of structure than required. 3. From performance point of view, the building should be so planned as to provide sufficient comfort & convenience to the occupants of building. • To perform these basic functional requirements, a building should satisfy the following requirements in design & construction. 1. Strength and Stability 2. Dimensional Stability 3. Durability 4. Damp Prevention 5. Fire Protection 6. Heat Insulation 7. Day-Lighting 8. Ventilation 9. Sound Insulation 10. Comfort and Convenience 11. Security against burglary 12. Termite Proofing 13. Economy
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  1. Strength andStability • The building should be strong enough to resist the loads safely. • The loads may be live load, dead load, wind load, snow load, earthquake load, etc. • The strength of a material refers to the capacity of the material to withstand stresses either of compression or tension. It is same as capacity of building/ structure to support the loads coming over it, safely. • The stability of a structure or its elements refers to its resistance to large overall deformation, such as overturning of wall or bulking of column. • The loads in a building is commonly classified into three types: Dead Load: They are static loads due to the weight of the respective structural members ex. Walls, partitions, roof & all other permanent fixtures in the building. Live load: These are incident loads due to material stored on the roof & floors or due to people use the building. Wind load: These load cause uplift of building & reduce pressure on the windward side & increases it on the leeward side. This is increases with the height of building. So this load is consider for design toll structures.
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  Height of buildingless than twice its effective width than this load is not consider. Snow load: In snow fall area the load of snow which is accumulated on roof slab is consider in design of building. If the roof slope angle is more than 500 then not required to consider the snow load. •The strength & stability also depends upon quality of materials, workmanship quality also. 2. Dimensional Stability This stability refers to the resistance to dimensional changes in building material & structures, due to following reasons:- • Elastic and plastic deformation due to applied loads. -During design of building effect of elastic deformation is take into account by considering effective modulus of elasticity. - In the design the factor of safety is generally used which is 1.5 times more than actual strength of material. • Expansion and contraction due to variation in temperature. -Avoid such materials which deforms when variations in temperatures -Providing unnecessary resistant to shrinkage or expansion of materials due to variations in temperature. • Expansion and contraction due to variation in moisture content. -Avoid such materials which deforms when variations in moisture content. -Providing unnecessary resistant to shrinkage or expansion of materials due to variations in moisture content.
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  3. Durability The buildingshould remain serviceable throughout its life. For this, the building should withstand the adverse effects of sun, wind, rain, etc. Durability of any material & method of construction further depends upon the condition of exposure to weathering. The detonation of exposed material of building due to • Crystallization of salts either present or conveyed, • Due to ground water movement, • Surface erosion by rain water, • Effect of sunlight on paints, rubber, plastic etc. This can be achieved by: • Proper design, • Proper maintenance, • Selection of proper materials • Protection of structure from adverse weathering effects through projecting eaves, coping, sunshades, parapets etc.
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  4. Damp Prevention •The building should remain dry. The presence of moisture in any building reduces the strength of materials, resulting in reduction in durability or failure of structure. • The dampness entered in building due to faulty design, poor workmanship & low quality of material. • Generally moisture enters in building through: 1. External walls: Rain water penetration 2. From ground through foundation walls: When water table in high & rain water 3. Roofs: Rain water penetration. • The entry of dampness in the building should be prevented by following cares: • A provision should be made, either at the outer surface or some where within the elements such as roofs, walls, floors etc of a complete impermeable or impervious membrane. Ex. Asphalt, metal roofing, paints on wood work or metal work etc. • Use such material that are permeable water but it allow it to pass so slowly that under the site conditions of wind, it will not reach the inner face before a drying out period follows. Ex. Use of masonry & roofing tiles are the materials of such characteristics.
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  • In externalwalls of building a provision can be made, behind the outer face of a continuous cavity to break the capillary paths along which the moisture travels. Ex Cavity wall • Effects of dampness: • Dampness creates unhealthy living & working conditions for the occupants. • Presence of damp conditions caused efflorescence on the building surface which ultimately may result in the disintegration of materials such as bricks, stones, tiles etc. & hence reduction in the strength. • It may result in softening & crumbling of plaster. • It may cause bleaching & flaking of the paints which results formation coloured patches on the wall & ceiling. • It may results in corrosion of metals used in construction. • Flooring materials like tiles are damaged due to loose adhesion with the floor base. • When timber is comes in contact with moisture or damp conditions get deteriorates due to effects of warping, bulking & rolling of timber. • All electric fittings get deteriorate causing leakages of electric current with the potential danger of short circuit. • Dampness promotes the growth of the termites & hence creates unhygienic condition in building.
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  5. Fire Protection •The building should not catch fire easily. To make the building completely fire proof is not a practically possible through may not be impossible. • This can be achieved by proper planning of building units in horizontal & vertical directions so stop the spreading of fire in horizontal & vertical directions. •Properly designing the structural elements such as walls, columns, beam etc & use of composite & non flammable materials depends upon requirements. •A building should provide means for the occupants to leave the building safely & quickly in the event of fire. • Select of fire-resistant building materials for construction of building. • Providing adequate fir extinguishing arrangements such as portable fire extinguishers, fire hydrants, etc. within the building. 6. Heat Insulation • The building should remain cool in summer and warm in winter. It helps to cut down the fuel costs in winter & to reduce the load on air conditioning equipments during summer. • The building should be designed or oriented such that there is no effect of external temperature which is changes on internal temperature of building & internal temperature should be maintain constant. • Heat insulation methods depends upon for what purpose building is used i. e. for use for persons or storage of material i.e. milk storage or cold storage for grapes etc.
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  • Following aresome methods used for heat insulation of building: • construct thicker external walls, which increases strength as well as providing insulation against heat & cold. • Construction of cavity wall provides protection from the outside heat as hollow space act as an insulation material. • Use of heat insulating materials such as slag wool, rock wool, light weight concrete etc for filling air spaces in construction of roof, wall & floors. • Maximum use of shading devices such as projecting chajja, roof, tree branches etc. • Proper orientation of building also help for heat insulation. 7. Day-Lighting • Day lighting not required so much light but sufficient light without or free from glare & it should come from right direction. • Good day light is essential, 1. To promote the activities carried out within the building. 2. To promote healthy living of the people. 3. To create pleasing environment within building. • Day lightening can be achieved by providing enough light for good seeing or as per requirements of room & by controlling direct & reflecting glare from
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  • The number& size of windows can be adjusted to meet the better requirement. • In actual practice, the size of window & openings are generally provided by considering climatic condition, therefore the designer should be balance lightening requirements with heat insulation. 8. Ventilation • Ventilation is nothing but supply of outside fresh air in to a building through windows or other openings, due to wind outside or convection effect arises form temperature difference between outside & inside of building. • The rate of fresh air requirements for different types of building are also recommended for human habitation. • Natural ventilation is achieved through openings such as windows, ventilators etc depends upon wind velocity. • The requirement of fresh air is achieved by use of mechanical ventilation in industrial buildings.
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  • Requirements ofventilation may be arise due to following reasons: 1. To prevent an undue concentration of body odors, fumes, dust & other industrial products. 2. To prevent an undue concentration of bacteria carrying particles. 3. To remove products of combustion (burning) & in some cases, to remove body heat & heat generated by the operation of electrical & mechanical equipments. 4. To create air movement, so as to remove the vitiated air or its replacement by fresh air. 5. To create healthy living conditions by preventing the undue accumulation of carbon dioxide, moisture, reduction of the oxygen content of the air. 6. To maintain conditions suitable to the contents of space. 7. To prevent flammable concentration of gas vapors or dust in case of industrial building.
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  9. Sound Insulation: Noise: Itis defined as unwanted sound & may be due to frequency of sound or intensity of sound or due to both. Types: a) Outdoor sound: It is type of sound which source is outside the building such as road traffic, railway, airplane, moving machinery etc. b) Indoor sound: It is type of sound which source is inside the building such as footsteps, banging of doors, shifting of furniture, home appliances etc. • Proper sound insulation is required because of following reasons: 1. After investigation on the effect of human comfort & annoyance have proved that, high noise condition not only result in uncomfortable living conditions, fatigue, inefficiency & mental strain but extended exposure to such conditions may cause temporary deafness or nervous breakdown too. 2. Sound proofing of rooms is as important as good acoustical design, particularly in case of film studios or sound studios of the radio stations etc. 3. Sound insulation has become more important requirement for buildings such as hospitals, education institutions, offices etc. & residential buildings located in urban areas. So therefore, it is desirable to keep the building free from the hashing effect of noise through proper planning & design to improve their living & working condition of occupants.
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  • The soundinsulation can be achieved through following means: 1. Planning against indoor & outdoor noise: To achieve the acceptable noise levels, as laid down by the standards or giving zoning regulations. 2. Adopting constructional measures: Use techniques such as cavity wall, air tight windows, floating floors over structural floors, floors with suspended ceiling etc depends upon the building requirements for sound insulation. 3. Reducing sound transmission through wall partitions: • Use of massive & rigid construction with air tight doors, windows etc. • Free from openings for pipes or ventilators • Use of non homogeneous structure for walls containing inert cells • Use of hard reflecting surface on the outside of the wall. • Use of cavity walls to prevent continuity of structure. • Use a insulation material as filling material in wall construction • Use of sound absorbent materials such as fiber board, hair felt, mineral wool etc for surface facing the other rooms. 4. Reducing sound transmission through floors: It is done by several ways,
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  • Provision ofsound insulating material like wood, cork, rubber etc between the floor covering & proper floor. • Use of rigid & massive floor construction • Use of hollow floor construction • Use of insulated & suspended ceiling • Use of resilient (flexible) floor covering such as carpet etc. • Use of floating floors etc. 5. Use of sound insulation materials such as compressed stew slabs, cork slabs, slag wool, felt, bitumen, asbestos etc use of an insulating layer of 1.5 to 3 cm is usually sufficient. • Maximum acceptable noise levels: • Dwelling (House & flats):- 45-55dB • Schools- 45-50 dB • Hospitals: 40-50dB • Public Offices: 53 -60 dB • Factory: 60-65 dB • Studio for ratio & T. V.: 25-30 dB • Auditoriums: 35-40 dB
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  10. Comfort andConvenience : • This is one of the basic requirement of functional design of building & should be satisfied by proper planning of building & its units. • To achieve same planning of building keep in view the various principles of planning. • To achieve comfort & convenience following points require more attention, 1. Grouping of rooms should be so planed as to ensure the better circulation, optimum utilization of space & use of minimum efficiency in building. 2. While planning living, working & health condition of occupants should be given more importance. 3. For comfort & aesthetic point of view, a building should provide enough light in day as well as at night for clear & easy vision without giving glare effect. 4. The orientation of building & its units should be made in such a way as to make the maximum use of natural gift like light, breeze, natural things like sea shore etc.
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  11. Security againstburglary : • This is the safety aspect or requirement of a building. • It should be given due consideration while designing & constructing the external walls of building. • External walls of a building should be strong enough to resist a burglar breaking & enter into house. • The window openings should be covered by Steel jallies, grills or such other devices. • Important buildings such as banks, Jewelry shops etc may also provided with automatic alarms, C.C.T.V.s, alarms, sirens within building. 12. Termite Proofing : • Termites are popularly known as white ants. • These insects, which are seen to raise from cracks & gaps in the walls & floors generally have their origin deep inside the foundations of building. • Dry wood termites, which live in dry wood in small colonies, cause grate damage to building located in humid coastal areas.
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  • Subterranean termites,which depends upon soil for their shelter & on wood for their food. • These termites easily enter into the building, through cracks of even 0.50mm thickness in concrete, masonry, pipe conduits, floor joints etc. • It is mainly affects on the structural safety & durability of building. • To avoid such termites following some precautions should be taken: 1. Use better quality foundation materials. 2. Properly selling of floor joints. 3. Cleaning building site containing dead wood, old tree stumps etc. 4. Treating wooden members in superstructure with suitable preservatives like paints etc. 5. The post construction treatment to protect from termites consist of opening earth around the building & treating it with chemicals. 6. If some portion of masonry, wood work etc damaged, in that portion holes are drilled & injecting chemicals under pressure in it.
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  13. Economy: • Thebuilding should be economical in long run. • The maintenance cost of the building should be as minimum as possible. • This can be achieved by using good quality construction materials, fixtures, finishes, etc.