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Unit weight of materials used in Construction 50+
Unit weight of materials used in Construction The unit weight of materials is an important factor to consider in engineering and construction projects. It refers to the weight of a material per unit volume, typically expressed in pounds per cubic foot (lb/ft^3) or kilograms per cubic meter (kg/m^3). Accurate knowledge of the unit weight of materials is crucial for various calculations and design considerations, ensuring the structural integrity and safety of the project. The unit weight of materials is a critical consideration in engineering and construction endeavors. It denotes the weight of a material per unit volume, often expressed in pounds per cubic foot (lb/ft^3) or kilograms per cubic meter (kg/m^3). Precise knowledge of the unit weight of materials is vital for accurate calculations and design considerations, guaranteeing the project’s structural integrity and overall safety. The unit weight of materials is important in engineering and construction projects as it indicates the weight of a material per unit volume. It is typically measured in pounds per cubic foot (lb/ft^3) or kilograms per cubic meter (kg/m^3). Accurate knowledge of the unit weight of materials is crucial for precise calculations and design considerations, ensuring the structural integrity and safety of the project. How do you find the unit weight of materials The formula for calculating unit weight of steel bars is Weight (W) = Volume (V) x Density (D). Therefore, we must first calculate the volume of the bar to calculate steel unit weight. Density of the steel typically ranges from 7750 to 8000 kg/m3. Unit Weight (kg/m3) = Mass (Kg)/ Volume(m3) ρ = M/V Conversion between Kg/m3 to KN/m3 and lb/ft3 is shown below. 1 kN/m3 = 101.9716 kg/m3 1 kg/m3 = 0.0624 lb/ft3 The unit weight of material or density of materials varies with the composition of the material. The unit weight of a material is very important in calculating the self-weight of the material, especially when evaluating the permanent actions in a structure. Without the knowledge of the unit weight of a material, it will be impossible to accurately estimate the self weight and the load it subsequently carries when used as a structural member. This article is dedicated to providing a handy list of the unit weight of various construction materials according to EN 1991-1-1:2002. The density of a material can vary depending on the composition, process of manufacturing, and other factors. However, the density of machine-made products is fairly constant (or controllable) when compared with the density of direct products of nature. Therefore, natural materials are expected to have slightly different properties even when they are occurring in the same place. Unit Weight Of Concrete And Mortar Materials Density (kN/m3) Hardened normal weight concrete 24.0 Reinforced concrete (normal percentage) 25.0 Fresh concrete 25.0 Cement mortar 19.0 to 23.0 Gypsum mortar 12.0 to 18.0 Lime-cement mortar 18.0 to 20.0 Lime mortar 12.0 to 18.0 Unit weight of natural stones Natural Stone Unit weight (kN/m3) granite, syenite, porphyry 27.0 to 30.0 basalt, diorite, gabbro 27.0 to 31.0 tachylyte 26.0 basaltic lava 24.0 Sand Stone 21 – 27 Dense Lime stone 20 – 29 Volcanic tuff 20.0 Other Limestone 20.0 slate 28.0 gneiss 30.0 Unit weight of timber and timber derived products Timber/timber derived product Unit weight (kN/m3) timber strength class C14 3.5 timber strength class C22 4.1 timber strength class C30 4.6 timber strength class D30 6.4 timber strength class D50 7.8 timber strength class D70 10.8 homogeneous glulam GL24h 3.7 homogeneous glulam GL32h 4.2 combined glulam GL24c 3.5 combined glulam GL32c 4.0 combined glulam GL36c 4.2 softwood plywood 5.0 birch plywood 7.0 laminboard and blockboard 4.5 chipboard 7.0 to 8.0 cement-bonded particle board 12.0 flake board, oriented strand board, wafer board 7.0 hardboard, standard and tempered 10.0 medium density fiber board 8.0 softboard 4.0 Unit weight of metals Metal Unit weight (kN/m3) Aluminum 27.0 Brass 83.0 – 85.0 Bronze 83.0 – 85.0 Copper 87.0 – 89.0 Cast iron 71.0 – 72.5 Wrought iron 76.0 Lead 112.0 – 114.0 Steel 77.0 – 78.5 Zinc 71.0 – 72.0 Unit weight of glass and plastics Material Unit weight (kN/m3) Broken glass 22.0 Glass in sheets 25 Acrylic sheet – plastic 12.0 polystyrene, expanded, granules 0.3 foam glass 1.4 Terracotta (solid) 21 Cork (compressed) 4 Unit weight of asphalt/pavement materials Material Unit weight (kN/m3) Asphalt and asphaltic concrete 24.0 – 25.0 Mastic asphalt 18.0 – 22.0 Hot rolled asphalt 23.0 Sand (dry) 15.0 – 16.0 Hardcore 18.5 – 19.5 Quarry dust 14.1 Roofs and roofing materials Material Weight per unit area (kN/m2) Steel roof trusses in spans up to 25 m 1.0 – 2.0 Corrugated asbestos-cement or steel sheeting, steel purlins etc. 0.4 – 0.5 Roofing felt and screed 2.0 Patent glazing (with lead-covered astragals), steel purlins etc. 0.4 Slates or tiles, battens, steel purlins etc. 0.7 – 0.9 Plain roofing tiles 0.6 – 0.9 Interlocking roofing tiles 0.6 0.45 mm gauge aluminum roofing sheet 0.014 Block works, brick works, partitions, and wall finishes Material Weight per unit area (kN/m2) 225 mm block work 2.87 150 mm sand concrete block work 2.15 Wall finishes (both sides) 0.6 12 mm plaster rendering 0.3 Two-coat gypsum 12 mm thick 0.215 Plasterboard 13 mm thick 1.1 Gypsum panels 75 mm thick 4.4 Clay hollow block 0.0113 / mm thick Common clay blocks 0.0189 / mm thick Engineering clay bricks 0.0226 / mm thick Refractory bricks 0.0113 / mm thick Refractory bricks 0.0113 / mm thick Floor finishes Material Weight per unit area (kN/m2) Clay floor tiles 0.575 25 mm thick terrazzo floor 0.6 37 mm thick screeding 0.8 Terrazzo paving 0.0222 / mm thick 6 mm thick glazed tile + adhesive 0.181 8 mm thick glazed tile + adhesive 0.214 10 mm thick glazed tile + adhesive 0.246 10 mm thick porcelain floor tiles + adhesive 0.275 8 – 10 mm thick vitrified floor tiles + adhesive 0.215 10 mm thick granite floor tiles + adhesive 0.346 12 mm thick granite floor tiles + adhesive 0.4 20 mm thick granite floor tiles + adhesive 0.622 5 types of supports and their
RIGID HIGHWAY PAVEMENTS
RIGID HIGHWAY PAVEMENT In concrete rigid highway pavements, the strength of the pavement is contributed mainly by the concrete slab, however, in flexible pavements; successive layers of the pavement contribute cumulatively. Since the modulus of elasticity of the concrete slab is much greater than that of the foundation material, a major portion of the load carrying capacity is derived from the slab it self. the slab has often been referred to as beam action. Types of rigid pavements Jointed unreinforced concrete pavements (JUCP) The pavement consists in a succession of cast in place unreinforced concrete slabs separated by joints to prevent expansion from developing stresses and to control cracks. The slabs are linked together by tie bars or dowels to transmit the vertical stresses. Jointed reinforced concrete pavements (JRCP) The pavement consists in a succession of cast in place reinforced concrete slabs separated by joints to control cracks. The slabs are linked together by tie bars or dowels to transmit the vertical stresses. JRCP are used where a probability exists for transverse cracking during pavement life due to such factors as soil movement and/ or temperature/ moisture change stresses. The longitudinal reinforcement is the main reinforcement. A transverse reinforcement though not absolutely necessary in most cases is usually added to facilitate the placing of longitudinal bars. Continuously reinforced concrete pavements (CRCP): Are used for rather highly trafficked roads where a good level of comfort is expected. The principal reinforcement , in the form of prefabricated mesh or reinforcing bars installed at mid-depth of the slab, is again the longitudinal steel which is essentially continuous throughout the length of the pavement. This longitudinal reinforcement is used to control cracks which form in the pavement due to volume change in the concrete. Basically, the use of the different types of rigid pavement is as follows: JUCP is suitable for all levels of traffic, whenever the risk of subgrade movement is low and an uncontrolled cracking not very prejudicial. JRCP is suit able for all levels of traffic is used when the risk of settlement s of and the subgrade can not be neglected. CRCP shall basically be considered only for rather high design traffic (>30 msa). The structural cross-section of a rigid pavement Typical Rigid Pavement structure The load bearing capacity of the soil subgrade is not important in the design of concrete pavements. The prime requirement is to provide a foundation on which construction traffic can operate without impairing the shape to which the surface trimmed. The capping layer consist s of selected fill and is provided in cases of low strength roadbed material. It protects the underlying subgrade from construction traffic loading and provides a stronger platform for the subbase layer, which is placed on top of the capping layer. Base courses are often called subbase courses when used with rigid pavements. These terms are often used interchangeably and it should be noted that either of the terms refers to a prepared layer of material immediately between the concrete slab and subgrade. The base courses (sub-bases) are utilized under these pavements for several reasons: ■ Control of pumping, at joint s and slab edges. ■ Control of frost action ■ Drainage ■ Control of shrink and swell of the subgrade due to volume changes in road bed soils susceptible to such phenomena ■ To expedite construction. ■ To provide a stable “working platform” for the construction equipment ■ To provide a uniform concrete slab support If water accumulates in the pavement under a joint, mud pumping is likely to occur as heavy vehicles pass from one slab to the next. If the subgrade soil is not free draining it is necessary provide to a subbase. should be free from draining and should continue through the road shoulder. Reinforcement in rigid highway pavements Dowel bars: ■ Are load transfer devices. They transfer load across transverse joints while checking on movement of the slabs. ■ It is thus necessary that adequate load transfer across joints limits slab deflections to reduce faulting, spalling and corner breaks. ■ Since they are load transfer devices, they must be fairly heavy and spaced at close intervals to provide resistance to bending, shear, and bearing on the concrete. ■ Dowel bars are used at joints on long slabs or where load transfer by “aggregate interlock” is suspect. Joints without dowels are generally satisfactory if the joint opening is 1 mm or less. Tie Bars ■ Are used to tie adjacent slabs together along the longitudinal joint tightly so that load transfer across is ensured. ■ Tie-bars at longitudinal joints are provided to hold these joints tightly closed and therefore perform a similar function to steel between transverse joints. ■ The purpose of a tie-bar is to hold reinforcement a joint tightly closed to allow load transfer by aggregate interlock. Distributed fabric steel reinforcement of wire ■ They are also called bar matts are and are used to control temperature cracking without increasing structural capacity. ■ It is usually placed at the mid depth of the slab and discontinued at joints. ■ The purpose of distributed steel or temperature steel is basically one of crack control. Temperature steel will not prohibit the formation of cracks but act s as a tie member, which controls the width of the crack opening. ■ It holds tightly closed any cracks that may form, thus maintaining the pavement as integral structural unit. Joints in rigid highway pavements Joint s are placed in concrete pavements, whether reinforced or not to permit expansion and contraction pavement, thereby relieving stresses due to environmental changes (temperature and moisture), friction, and to facilitate construction. Contraction joints ■ Provided to relieve tensile stresses due to temperature, moisture and friction, therefore the controlling cracking. Expansion joints They are transverse and are used to relieve compressive stresses from the expansion of concrete. They are expensive to maintain and are susceptible to pumping. The primary function of an expansion joint is to provide space for the expansion of the
Highway Pavement Complete in Simple Terms. You should know.
Introduction A highway pavement is a structure consisting of superimposed layers of processed materials above the natural soil sub-grade, whose primary function is to distribute the applied vehicle loads to the sub-grade. The pavement structure should be able to provide; a surface of acceptable riding quality, adequate skid resistance, favorable light reflecting characteristics, low noise pollution. A Highway Pavement is a structure made up of carefully selected and well proportioned materials in different layers designed to transfer loads applied to the surface so that the underlying subgrade is not overstressed. The ultimate aim is to ensure that the transmitted stresses due to wheel load are sufficiently reduced, so that they will not exceed bearing capacity of the sub grade. Two types of pavements are generally recognized as serving this purpose, namely flexible pavements and rigid pavements. Types of pavements Rigid pavements Flexible pavements. Rigid pavements. RIGID: applied to wearing surfaces constructed of Portland cement concrete. A pavement constructed of concrete is assumed to possess considerable flexural strength that will permit it to act as a beam and allow it to bridge over minor irregularities, which may occur in the base or subgrade on which it rests; hence the term rigid. A concrete base that supports a brick or block layer might also be described as rigid. Flexible Pavement. On the other hand, a flexible pavement is a structure that maintains intimate contact with and distributes loads to the subgrade and depends on aggregate interlock, particle friction and cohesion for stability. Thus the classification of flexible pavements includes primarily those pavements that are composed of a series of granular layers topped by a relatively thin – quality bituminous wearing course. Typically, the highest – quality materials are at or near the surface. Requirements of a Highway Pavement An ideal pavement should meet the following requirements: 1. Sufficient thickness to distribute the wheel load stresses to a safe value on the sub-grade soil, 2. Structurally strong to withstand all types of stresses imposed upon it, 3. Adequate coefficient of friction to prevent skidding of vehicles, 4. Smooth surface to provide comfort to road users even at high speed, 5. Produce least noise from moving vehicles, 6. Dust proof surface so that traffic safety is not impaired by reducing visibility, 7. Impervious surface, so that sub-grade soil is well protected, and 8. Long design life with low maintenance cost. FLEXIBLE HIGHWAY PAVEMENT Factors affecting the performance of flexible pavements ⦿Traffic ⦿Soil and pavement materials ⦿Environment ⦿Construction and maintenance practice. ⦿Traffic Traffic has a major effect on pavement performance. Traffic characteristics that affect performance are traffic load, traffic volume, tyre pressure, and vehicle speed. Traffic load produces stresses and strains within the pavement structure and the subgrade, which gradually contribute to the development of pavement distresses. For example, heavier loads result potential for fatigue cracking and rutting. Traffic volume affects pavement performance since larger number of load repetitions increases the chance for fatigue cracking. Higher tyre pressure produces higher stress concentrations at the pavement surface that could result in rutting and shoving in the HMS layer. Vehicle speed affects the rate of applying the load. Since asphalt concrete is a visco-elastic plastic material, its response is affected by the rate of load application. Slow or stationary vehicles have more chances of developing rutting and shoving than high-speed vehicles. On the other hand, high travel speeds cause more severe bouncing of vehicles, and result in larger dynamic loading and increased roughness. Design Vehicle ◾Length – capacity of a lane ◾Width – overtaking and capacity ◾Height – clearance at bridges, overheads etc ◾Weight – load to be imposed on to the pavement ⦿Soil and highway pavement materials Soil and pavement materials significantly affect pavement performance. High quality materials are needed to provide good support to traffic loads under various environmental conditions. Important material properties include mechanical properties such as elasticity, visco-elasticity, plasticity, temperature susceptibility, durability and aging characteristics. These properties affect how the material responds to traffic loads and environmental conditions such as temperature, freeze thaw effect, and rain. ⦿Environment/Climate Environmental conditions that affect pavement performance include moisture, temperature, and their interaction. For example, moisture may reduce subgrade support and weakens various pavement layers. High temperatures soften asphalt concrete and could create rutting within the surface layer. Temperatures below freezing have a bad effect on pavement performance, especially cycles of freeze and thaw. ⦿Construction and maintenance practice. Poor construction procedure will almost always ensure poor pavement performance. For example, poor compaction of subgrade or any pavement layer allows excessive further compaction by traffic, which appears in the form of rutting and surface cracking. Poor placement of Hot Mixed Asphalt (HMA) during construction may result in weak transverse or longitudinal construction joints that are susceptible to early cracking and deterioration. Excessive air voids in the HMA layer due to poor compaction will result in fast aging followed by cracking. In contrast, too much compaction of HMA will result in too small amount of air voids that could create rutting or bleeding. Lack of smoothness of the pavement during construction increases the dynamic impact of traffic, and consequently, speeds up the rate of developing roughness during service. Design Procedures For Flexible Pavements Design of flexible pavement entails two steps Mix Design Structural design Mix design involves the determination of the relative proportions of a mixture, while structural design involves the determination of the layer thicknesses for the components of a pavement structure. In structural design of pavements, the objective is to determine for the given set of materials, the layer thicknesses required for the pavement to serve. Methods of design AASHTO Road Notes developed by TRL Method CBR method MoWT method Group index method. Westergard method. CBR method. Benkelman beam method. Design input factors Traffic Material characteristics Environmental considerations Costs to be involve Traffic Traffic is considered in terms of axles. Types of axles include: Single axles Tandem axles Tridem or triple axles Typical cross-section of a flexible pavement Types of Flexible Pavements 1. Conventional layered flexible pavement,
The 4 Different Types Of Flow in Channels
Different Types Of Flow in Channels The Types Of Flow in Channels can be classified into following types depending upon the change in the depth of flow with respect to space and time. Steady Flow and Unsteady Flow Flow in a channel is said to be steady if the flow characteristics at any point do not change with time that is (∂V/∂t)= 0, (∂y/∂t) = 0 etc. However, in the case of prismatic channels the conditions of steady flow may be obtained if only the depth of flow does not change with time, that is (∂y/∂t) = 0. On the other hand if any of the flow characteristics changes with time the flow is unsteady. Most of the open channel problems involve the study of flow under steady conditions and therefore in this chapter only steady flow has been considered. Uniform and Non-uniform (or Varied) Flow. Flow in a channel is said to be uniform if the depth, slope, cross-section and velocity remain constant over a given length of the channel. Obviously, a uniform flow can occur only in a prismatic channel in which the flow will be uniform if only the depth of flow y is same at every section of the channel, that is (∂y/∂s) = 0. Flow in channels is termed as non-uniform or varied if the depth of flow y, changes from section to section, along the length of the channel, that is (∂y/∂s) is not equal to zero. Varied flow may be further classified as rapidly varied flow (R.V.F.) and gradually varied flow (G.V.F.). If the depth of flow changes abruptly over a comparatively short distance, the flow is characterized as a rapidly varied flow. Typical examples of rapidly varied flow are hydraulic jump and hydraulic drop. In a gradually varied flow the change in the depth of flow takes place gradually in a long reach of the channel. Laminar Flow and Turbulent Flow. Just as in pipes, the flow in channels may also be characterized as laminar, turbulent or in a transitional state, depending on the relative effect of viscous and inertia forces and alike pipes, Reynolds number Re is a measure of this effect in channel flow also. However, the Reynolds number for flow in channel is commonly defined as Re = 〈ρVR〉/u, where V is the mean velocity of flow, R is the hydraulic radius (or hydraulic mean depth) of the channel section and ρ and μ are respectively the mass density and absolute viscosity of water. On the basis of the experimental data it has been found that up to Re equal to 500 to 600 the flow in channels may be considered to be laminar and for Re greater than 2000 the flow in channels is turbulent. Thus for Re in between 500 to 2000 the flow in channels may be considered to be in transitional state. Since most of the channel flows are turbulent, in this chapter only the turbulent flow has been dealt with. Subcritical Flow, Types Of Flow in Channels Critical Flow and Supercritical Flow. As stated earlier gravity is a predominant force in the case of channel flow. As such depending on the relative effect of gravity and inertia forces the channel flow may be designated as subcritical, critical or supercritical. The ratio of the inertia and the gravity forces is another dimensionless parameter called Froude number Fr which is defined as Fr = VgD ; where V is the mean velocity of flow, g is acceleration due to gravity and D is hydraulic depth of channel section (as defined in Section 15.3). As indicated later, when Fr = 1, that is V = gD , the channel flow is said to be in a critical state. If Fr < 1, or V < gD , the flow is described as subcritical or tranquil or streaming. If Fr >1, or V > gD , the flow is said to be supercritical or rapid or shooting or torrential. GEOMETRICAL PROPERTIES OF CHANNEL SECTION The geometrical properties of a channel section can be defined entirely by the geometry of the section and the depth of flow. Some of the geometrical properties of basic importance are defined below. The depth of flow y, is the vertical distance of the lowest point of a channel section from the free surface. The top width T is the width of the channel section at the free surface. The wetted area A (or water area or area of flow section) is the cross-sectional area of the flow normal to the direction of flow. The wetted perimeter P is the length of the channel boundary in contact with the flowing water at any section. The hydraulic radius R (or hydraulic mean depth) is the ratio of the wetted area to its wetted perimeter, or R = A/P The hydraulic depth D is the ratio of the wetted area to the top width T, or D = A/T The section factor for critical flow computation Z is the product of the wetted area and the square root of the hydraulic depth, or Z = A√D = A√A/T = 〈A3/T〉1/2 The section factor for uniform flow computation AR2/3 is the product of the wetted area and the hydraulic radius to two-thirds power. The table below provides a list of the expressions for the geometrical properties of five commonly used channel sections. Readmore.
01, What Is Concrete/Detailed, Everything To Know
Concrete What is concrete Concrete is a building material made by mixing cement, fine aggregates/sand, coarse aggregates/gravel with water and allowed to hardened to get a solid material. if concrete is produced in its appropriate standards, then concrete can be a durable, watertight and highly compressive building material. Fresh concrete is usually posses fluid-like form which enables the hardened form to be achieved in different forms by the aid of a suitable form work. Quality control is essential prior to and post placement of concrete. Application of concrete Reinforced concrete buildings/bridges Concrete is mostly used in construction of reinforced concrete structures, such as columns/abutments, slabs/decks, beams, staircase, ramp, shear wall, etc. The concrete is casted directly into already created formwork, compacted, cured and formwork removed to form the solid hardened concrete, formwork maybe removed after a week before completion of curing or after curing. Precast Building components. During modular constructions, concrete can be used to produce these precast components such as columns, slabs, beams, toilet slabs, wall units, etc. These components are produced in a workshop or in a factory. They are usually produced to high standard with the right constituent proportioning and accurate required level of curing, and transported to the site for assembling, read more about precast units. Precast decorative units Concrete can be used to make precast decorative units, animals, pots, seats etc. These items are usually produced either by manually modelling or using suitably designed formworks. For monumental/animal structures, they are usually modeled manually, other items like pots are usually modelled in a formwork etc. Structural footings When it comes to structures such as buildings, bridges, dams, wells, steel structures, tunnels, culverts, etc there foundation structures are supported beneath with reinforced or plain concretes, due to the reason that concrete is a good compressive material and able to transmit the loads to soils uniformly and creates a firm base, this can be inform of pad footings, strip footings, raft, grillage etc. Material Advantage Of Concrete Concrete can be used any where due to the fact that its ingredients are readily available it is extremely flexible building material, capable of taking virtually any shape As a material, it is strong as natural stone, it is durable and resistant to the elements It requires a minimum of highly skilled laborer to mix and place Concrete ingredients Portland cement Portland cement is manufactured from lime, silica, iron oxide and alumina. in its dry state, Portland cement is a very fine powder. When mixed with water, a paste is formed , as it hardened the paste looses its plasticity. The initial setting occurs in about one hour and the final setting in ten hours, the cement however continues to harden until its full strength after 28days. the Portland cement paste is the one used to bind the fine and the course aggregates. Fine aggregates Consists of sand and other suitable fine material fills the spaces between the coarse aggregates Fine particles are necessary to allow for good workability and smooth surfaces when hardened An excess of fine aggregates requires an increase in cement, increasing cost and overall shrinkage of the mix. Coarse aggregate Consists of crushed stone or gravel larger than the fine aggregates, but small enough to fit between reinforcement bars Should be hard and durable as opposed to soft and flaky Water Water must be clean from oil, alkali, acid etc. Simply it should be drinkable.
2.0 Revealing Types Of Loads On Structures
Different Types Of Loads On Structures When it comes to design of structures for sustainability, there are usually two major factors that we must as structural engineers/designers consider that is Economy and Safety. if the economy is taken seriously with consideration of lesser loads applied on the structure, then the safety of the structure is compromised. if loads applied on the structures are considered the most and applied applied to the structure, then the cost of construction increase. therefore, for a balanced sustainable structure, the estimation of various loads acting on the structure is to calculated precisely. The Eurocodes, Indian standard code IS: 875–1987 and American Standard Code ASCE 7, the Minimum Design Loads for Buildings and Other Structures specifies various design loads for buildings and structures. The Different Types Of Loads On Structures. The Loads On Structures can be broadly classified into different categories depending on the direction of their actions on the structure. Vertical loads Horizontal loads Longitudinal loads, These loads on structures can further be categorized as listed below Permanent/Dead loads Variable/Live/Imposed loads Wind loads Seismic loads Snow loads Rain loads Accidental loads/Explosion Permanent/Dead loads The first vertical load that is considered is dead load. Dead loads can not be moved or stationary loads which are transferred to structure throughout the life span of the structure. permanent load is first of all as a result to self weight of structural members such as beams, columns, slabs, staircase, shear wall, permanent partition walls, fixed permanent equipment and different material weights. It majorly consists of the weight of roofs, beams, walls and column etc. which are actually the permanent parts of the building/structure. The calculation of dead loads of each structure are calculated by the volume of each section and multiplied with the unit weight. Unit Weight Of Some Common Building Materials Sl. No Material Weight 1 Stone Masonry 20.4-26.5 kN/m3 2 Brick Masonry 18.8 kN/m3 3 Plain Cement Concrete 24 kN/m3 4 Reinforced Cement Concrete 25kN/m3 5 Timber 5-8 kN/m3 6 Finishes 20kN/m3 Variable/Live/Imposed loads The second vertical load that is considered in design of a structure is imposed loads or live loads. Live loads are either movable or moving loads with out any acceleration or impact. The loads are assumed to be produced by the intended use or occupancy of the building including weights of movable partitions or furniture etc.. Live loads keeps on changing from time to time. These loads are to be suitably assumed by the designer. It is one of the major load in the design. The minimum values of live loads to be assumed are given in Eurocode 1. It depends upon the intended use of the building. The code gives the values of live loads for the following occupancy classification: Categories of use Category Specific use Example A Areas for domestic and residential activities Rooms in residential buildings and houses; bedrooms and wards in hospitals; bedrooms in hotels and hostels kitchens and toilets. B Office areas C Areas where people may congregate (with the exception of areas defined under category A, B and D1)) C1: Areas with tables, etc e.g. areas in schools, cafes, restaurants, dining halls, reading rooms, receptions C2: Areas with fixed seats, e.g. areas in churches, theatres or cinemas, conference rooms, lecture halls, assembly halls, waiting rooms, railway waiting rooms.C3: Areas without obstacles for moving people, e.g. areas in museums, exhibition rooms, etc. and access areas in public and administration buildings, hotels, hospitals, railway station forecourts C4:Areas with possible physical activities, e.g. dance halls, gym nastic rooms, stages . C5:Areas susceptible to large crowds, e.g. in buildings for public events like concert halls, sports halls including stands, terraces and access areas and railway platforms. D Shopping areas D1: Areas in general retail shops. D2: Areas in department stores. NOTE . Depending on their anticipated uses, areas likely to be categorized as C2, C3, C4 m ay be categorized as C5 by decision of the client and/or National annex The code gives uniformly distributed load as well as concentrated loads. The floor slabs have to be designed to carry either uniformly distributed loads or concentrated loads whichever produce greater stresses in the part under consideration. Since it is unlikely that any one particular time all floors will not be simultaneously carrying maximum loading, the code permits some reduction in imposed loads in designing columns, load-bearing walls, piers supports and foundations. Some of the important values are presented in table below which are the minimum values and wherever necessary more than these values are to be assumed. Imposed Loads On Structures/floors, balconies and stairs in buildings Category of loaded area qk (KN/m2) QK (KN/m2) Category A – Floors – Stairs – Balconies 1,5 to 2,0 2,0 to 4,0 2,5 to 4,0 2,0 to 3,0 2,0 to 4,0 2,0 to 3,0 Category B 2,0 to 3,0 1, 5 to 4,5 Category C– C1 – C2 – C3 – C4 – C5 2,0 to 3,0 3,0 to 4,0 3,0 to 5,0 4,5 to 5,0 5,0 to 7,5 3,0 to 4,0 2,5 to 7,0 (4,0) 4,0 to 7,0 3,5 to 7,0 3,5 to 4,5 Category D-D1 -D2 4,0 to 5,0 4,0 to 5,0 3,5 to 7,0 (4,0) 3,5 to 7,0 Wind loads/Loads On Structures Wind Loads On Structures are the horizontal loads caused by the movement of air relative to earth. Wind load is required to be considered in structural design especially when the height of the building exceeds two times the dimensions transverse to the exposed wind surface. For low rise building say up to four to five stories, the wind load is not critical because the moment of resistance provided by the continuity of floor system to column connection and walls provided between columns are sufficient to accommodate the effect of these forces. Say for building exceeding 5 stories, wind load design must be considered and loads applied according to the wind zones in the specific area provided by the design codes. The specific Eurocode for wind actions are listed below:
A complete Detailed Structural Drawing
A complete Detailed Structural Drawing. PROJECT; MULTI-PURPOSE CENTER LOCATION, CITY OF BORONGAN, EASTERN SAMAR CLIENT; IOM/UNICEF Document issued for bidding. File access You can also download document here.
4+ Elite Masonry Bonding Procedures
Masonry Bonding Procedures Working drawing When drawings are received on the site, they should be carefully studied so that the work to be done is carefully understood. care should be taken before setting out any walling to a certain form of drawing. Setting of equipment Before setting out any work, the tape should be carefully checked for accuracy. Metallic linen tapes tend to stretch after they have been in use, so it is wise to check them against a known length, such as a measuring chain. Erecting a corner When the pegs are fixed and the gauge rod set out, the corner should be erected. The corners should not be too large, for its much more economical to run a wall with the aid of a line than building up a large portions of walling as a corner. The corners should preferably be racked than toothed. Toothing is very difficult to secure a solid joint because it gives a point of weakening mostly if there is a slight movement in the foundation. Obtuse Angles in Flemish Bond Internal and External Obtuse Angels An alternative method of building an obtuse angels in Flemish bond without using squint bricks INTERNAL OBTUSE ANGLES Internal obtuse angles in English and Flemish Bond Internal obtuse angles RACKING BACK Broken Bond This occurs within a wall when the space does not fit a full brick size. it is much better to avoid a broken bond, but where openings and pliers do not allow for brick sizes, the broken bond must be carefully set out once their position has been settled and this should be maintained throughout the right of the wall. A closer should not be placed in the middle of the wall. 1/2 bat of 3/4 bat is always preferred. Jambs and reveals Jambs and reveals maybe two types i.e. Square or recessed. The square reveals are easier to form and generally stronger. The unbound of brick cutting necessary to form the bond for recessed jamb tends to create weakness. The principal of bonding at reveal is similar in all cases. But in Dutch bond it requires more cutting. Fixing Window Frames to reveal There are many methods of securing frames to reveals but this depends on the type of frame and the material into which they are fitted. Metal frames which have no timber lining are usually secured with steel lugs fixed a countersunk bolt nut not the frame, and built into the reveal. BONDING ACUTE ANGLES An alternative method of bonding an acute angle in Flemish bond Obtuse angles in English bond An alternative method of building an obtuse angle in English bond without using squint bricks Read more on Masonry Bonding Procedures
5 types of supports and their Characteristics
Types of supports and their Characteristics/ their applications. The type of support provided for a structure is important in ensuring its stability. Supports connect the member to the ground or to some other parts of the structure. There are three basic idealized support structure types, categorized by the types of deflection they constrain: roller, pinned, fixed, hanger and simple support. Roller supports. Pinned support. Fixed support. Hanger support. Simple support. Varieties of support. Roller supports This is the type of support which only restrains the structure from moving in one or two perpendicular directions. However, the structure can move in the other directions and it can also rotate. The joint that is supported by a roller support has four or five degrees of freedom. If the structure acts as a two-dimensional system, the roller support restrains the node form moving in one direction only. In general, there is a support reaction (force acting from the support to the structure) in the direction of the restrained degree of freedom. Therefore, roller supports have one or two support reactions. Roller supports are used in bridges and spatial structures to allow for thermal movements. Roller supports are often used with other types, such as fixed or sliding supports, to provide a stable and secure foundation for a structure. They are particularly useful in situations where the supported object is subject to lateral loads, as they allow the object to move or rotate in response to these forces, reducing the stress on the structure. Roller supports are also used in various other applications, including conveyor belts, rolling mills, and material handling systems. They can be generated in determinate and indeterminate structures. They are typically made of materials such as steel or other high-strength metals and are designed to withstand the loads and stresses associated with their intended use. Examples of Roller Supports Roller supports to allow the movement of a structure or object along a fixed path. Examples of roller supports include conveyor belts, sliding doors, and roller coasters. Here are a few more examples of how roller supports are used: Bridges: Roller supports are commonly used in the construction of bridges to allow for movement or rotation of the bridge deck in response to applied loads. The roller supports allow the bridge to move or rotate slightly, reducing the stress on the structure and increasing its stability. Cranes: Roller supports are also used in constructing cranes to allow for the rotation of the boom and other parts of the crane. The roller supports allow the crane to rotate and move freely while providing a stable and secure foundation for the structure. Conveyor belts: Roller supports are used in conveyor belts to support and guide the movement of the belt. The roller supports allow the belt to move smoothly and continuously while providing a stable foundation for the belt and the materials being conveyed. Rolling mills: Roller supports are used in rolling mills to support and guide the movement of the rolls. The roller supports allow the rolls to rotate and move freely while providing a stable foundation for the rolls and the materials being processed. Material handling systems: Roller supports are used in material handling systems to support and guide the movement of materials. The roller supports allow the materials to move smoothly and continuously while providing a stable foundation for the materials and the handling equipment. Pinned supports Pin or hinge support is used when we need to prevent the structure from moving or restrain its translational degrees of freedom. Most supports for architectural structures (except concrete structures) are of this type. When used for spatial structures, these supports have three reactions; however, there are only two reactions in two-dimensional structures. Also known as Hinged supports are typically used when it is necessary to allow for rotational movement of a structure or object, but not necessarily translation (movement in a straight line). They are often used with other types of supports, such as roller or fixed supports, to provide a stable and secure foundation for a structure. Hinged supports are typically made of materials such as steel or other high-strength metals and are designed to withstand the loads and stresses associated with their intended use. They are also commonly used to construct joints in robotics and other mechanical systems. Examples of Hinged Supports Hinged supports, also known as pivot points or pin joints, allow for rotational movement around a fixed point. Hinged support includes hinges on doors, folding tables, and the human elbow joint. Here are a few examples of how hinged supports, also known as pin joints or hinges, are used: Machinery: Hinged supports are also used to construct various types of machinery, such as presses and other manufacturing equipment, to allow for rotational movement and adjust the machinery. The hinges allow the machinery to rotate and move freely while providing a stable and secure foundation. Bridges: Hinged supports are used in the construction of certain types of bridges, such as swing and bascule bridges, to allow for rotational movement of the bridge deck. The hinges allow the bridge deck to rotate around a fixed axis, allowing the bridge to open and close to allow the passage of boats or other vessels. Doors: Hinged supports are commonly used to construct doors to allow for rotational movement around the hinges. The hinges allow the door to swing open and close while providing a stable and secure connection between the door and frame. Gates: Hinged supports are also used to construct gates to allow for rotational movement around the hinges. The hinges allow the gate to swing open and close while providing a stable and secure connection between the gate and the gate posts. Cranes: Hinged supports are used in constructing cranes to allow for rotational movement of the boom and other crane parts. The hinges allow the crane to rotate and move freely while providing a stable and secure foundation for the structure. Fixed supports Fixed supports are points of a structure that do not allow movement or rotation. The support reactions at fixed support can