Reinforced Concrete Structure of a Parking Garage

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Reinforced concrete structure of a Parking Garage 16

ReinforcedConcrete Structure of a Parking Garage

ReinforcedConcrete Structure of a Parking Garage

Parkingstructures are paramount for daily activities in both the urban andthe suburban places owing to its impression to the visitors and hencethe doing of business and traffic flow. Therefore the parkingstructure ought to satisfy the essential construction requirements ofsafety and be secure to the environment alongside it being friendlyto the users and also ease of use.

Theconstruction of parking garage therefore, entails the balance of thefactors and a logical plan to fulfill the site selection, the usercomfort and the budget requirements. Conception ideals are to beadhered to from the onset of the project to completion and a host ofconsiderations are taken that determine the final design and cost ofthe project hence the value impact on the customer.

Thereinforced concrete is the predominant material used in theconstruction of the parking garage hence the composition of itsstructure vital in the achievement of the required characteristics ofdurability, economy, workability and strength. The concrete shouldtherefore, be mixed, batched and delivered in accordance with ASTM C685 standards (Díazde León, 2015).The use of the professionals and the precast concrete instituteguidelines ensures the highest efficiency, speed and the costmanagement. The different design satisfactions are sort forconcerning the reinforced concrete that is used in the parking garageconstruction.

Inthis regard, durability is one such factor. In achieving thisrequirement, the concrete has to be exposed to moisture and chlorideswith low water to cement ratio and the compressive strength of 5000pounds per square inch at the minimum. Durability is also achieved bythe use of steel especially in areas where salts permits a higherstrength compression of the material increasing durability at thesame time reducing permeability. Since durability is often criticalespecially where heavy loads are frequented as is often the case aminimum compressive strength of 4000 psi (28MPa) is required.

Inorder to achieve the maximum strength of the reinforced concrete, ithas to be cured at an optimum rate, with precise moisture, optimumtemperature and the suitable environmental conditions. In ensuringthe economy of the concrete structure, the cement contents should beminimum and consistent with strength and durability requirements withwell graded aggregates and admixtures also playing a part in thecosting. Incorporating the supplements of the cement materials alsocaters for cost reduction. The selected concrete has to satisfy theworkability requirement by meeting the specifications (Díazde León, 2015).These include for instance the slump for slip form which is 25mm.Other factors in consideration are the grading of aggregates, watercontent and air content.

Thedesign of the reinforced concrete structure therefore, requires acareful selection of the dimensions and other required details of theslab that will enable the parking garage to sustain the traffic loadanticipated, ensure the proper joint locations can be achieved andallow economical construction. Proper thickness selection of the slabis the most important aspect of structural design of the parkinggarage reinforced concrete. While excessive thickness is costly,inadequate thickness will result to premature maintenance, poorperformance and the need for early replacement.

Moreso, differential shrinkage and expansion of the slab that is causedby the differential changes in the surfaces due to the variances inthe content of the moisture level and temperature and this causes theslab to curl up and down. This is reduced by minimizing the size ofthe slabs or increasing the thickness of the slab.

Figure1: Sample structural drawing of a slab

Fromthe drawing above, the shaded area represents area between theconcrete surface and the rebar material. The rebar is distributedadjacent to the top and bottom surfaces to provide reinforcement ofthe concrete and cushion it from cracks associated with the frequentexpansion and shrinkage and also the frequent loading associated withheavy trucks and other vehicles.

Figure2: Sample structural drawing of a beam

Therebar type 20 ø 20 is used for the beam as indicated above,positioned at the areas adjacent to the edges of the beam. They helpabsorb the loads and neutralize the effects of shrinkage andexpansion. The stirrups are indicated below the beam as shown alongits longitudinal length. The shaded area indicates area between theconcrete column and the rebar distribution.

Figure3: Sample structural drawing of column and foundation

Also,the rebar type 20 ø 20 is indicated by the lines inside the concretecolumns as shown. They are dense in the foundation and column as theydo support the heavy loads (Díazde León, 2015).They, therefore, absorb the effect of shrinkage and expansion in theconcrete that results from the heavy loads.

Estimatingof the total quantity of concrete and cost

Sizeof the slab sample

Thicknessof the slab = 10 in. (0.28 yd.)

Widthof the slab = 60 in. (1.67 yd.)

Lengthof the slab = 72 in. (2.0 yd.)

Totalvolume = 0.94 yd3

Sizeof the foundation and column sample

Foundationlength = 60 in. (1.67)

Foundationheight = 14.5 in. (0.4 yd.)

Foundationwidth = 72 in. (2.0 yd.)

Totalvolume = 1.34 yd3

Columnsample measures 10 in. (0.28yd.) by 10 in. (0.28yd.) by 72 in.(2yd.)

Totalvolume = 0.16yd3

Beammeasurements

10in. (0.28yd.) by 72 in. (2yd.) by 14.5 in. (0.4yd.)

Totalvolume = 0.22yd3

Totalvolume of the slab will be 0.94 + 1.34 + 0.22 + 0.16 = 2.66yd3

1yd3= approximately $75

Thereforethe total cost of the concrete is 2.44 x 75 = $200

Estimatingthe total quantity of rebar in tons and the cost

Therebar type 20 ø 20

Steelquantity required in constructing a slab is approximately 65kg/m3

0.72m3of slab require 46.8 kg

Steelquantity required in constructing a beam is approximately 220kg/m3

0.17m3of beam require 36.6 kg

Incolumns, it`s approximately 250kg/m3

0.12m3of column require 30.2 kg

Infoundations, it`s approximately 120kg/m3

1.0m3of foundation concrete require 120 kg

Thetotal quantity of rebar required is 46. 8 + 36.6 + 30.2 + 120 = 233.6kg

1kg of rebar is approximate $2

Thereforetotal cost of rebar required is 9 x 233.6 = $467.2

Thenumber of equipment or tools required for this operation variesconsiderably depending on the number of operations to be undertaken.Also, the materials to be used in the construction of the reinforcedconcrete for the foundation and slab for the parking floor. Thestandard equipment to be used includes the following: a winch that iseither hand operated or powered and suits the vessel size that ismovable. A hacksaw of up and over motion with the capacity of 150mmfor slicing of the reinforcing material such steel bars isappropriate. A band saw for slicing the wood material of the 32mcapacity. The circular saw to be used for cutting the jointing woodswith the 400mm with blade capacity. Planer with blade capacity of 400mm. Shavings and fumes are also required as extraction equipment.

Theother set of equipment to be used for the project includes the looseequipment that is essential for hull fabrication, and they includethe following: the vibrator or simply the hammer for depending on thescale of the operation to be used together with non-vibratory drillsof 10mm and 13 respectively. Additionally, a 20mm stand drillcomplete with bits is required for firmly holding the work in place.The other set of equipment for basic operations include, plaster orjust a pan type mixer of capacity 3-5 ft3/2.3-3.8m3,a 2 HP electric vibrators, a 200 mm set of test sand sieves with atray, a 6 cube cylinders with a base size of 600mm by 16 mm, a slumptest cone of BS standard, water tanks preferably of galvanized ironmaterial, a 25 ton hydraulic jack, the wire ropes for the winch, arod bending equipment and wheelbarrows.

Thesimple tools to used are rod spacers, curing equipment such as 100ghessian, chipping hammers, claw hammers, sledge hammers, tape rule of30 m, plumb bobs, spirit level of 300 – 900 mm, bevel adjustments,wood chisels, square of 300 mm, adjustable square of 255 mm,engineers vices, wooden floats, trowels, sand measuring box with thesize 305 x 305 x 280 mm and cement measuring box of the same size.

Whileundertaking this project, a host of safety procedures should beobserved so as to provide prevention against both short term andpermanent impairment. A safety plan has, therefore, to be initiatedto protect the user against injury from the tools and equipment, thejob conditions and also health hazards that may be as a result ofexposure to fumes such as those of the cement material.

Thesafety plan is made up of the protective gear by the user, the usesafety apparatus, and taking safety measures in case of unsafeconditions and injury to the user. The detailed safety plan for theproject would entail the guidelines as discussed. Personal protectionto observed by wearing of the hardhats and using protective hearingmasks while in the construction site where overhead hazardousmaterial sustained noise are often occasioned. The user while workingwith construction materials such as sand, cement, and any finematerial used shall have to use a respirator that will preventagainst respiratory health hazards.

Theequipment and tools utilized on the construction site should be wellequipped and properly maintained as per the safety recommendations ofthe manufacturer. The tendency to disable or remove safety devicesshould always be avoided. The equipment which is deemed as unsafe orotherwise inoperable should always be marked as such preventing itsfurther use hence avoid injury to the user and its damage.

Theuser should be trained by equipment experts and tested before beingpermitted to operate the equipment. The user should also ensure thatthe job site is safe and free of hazards before undertaking theconstruction of the project. The job site space should also beconfigured.

Theduration of construction of the reinforced depends on the amount oftime each of the activities involved in the process takes. Theconstruction activities are to be performed in the sequence whichwould require a schedule. Scheduling would, therefore, determinealbeit in estimates the duration that each activity takes to becompleted, the workforce allocated to each of the activities and alsothe provide guideline on which activity precedes the other.

Theplanning of these activities takes into account definition of worktasks, the method to be used in performing the tasks and theinteraction of the givens tasks. The first activities for thisproject involve site selection and bringing the constructionmaterials to the job site with the layout and plan of the parkinggarage already prepared. These would be allocated an estimatedduration of two days. These activities which follow are clearing,filling and finishing which includes seeding and sodding. They aremajorly earthwork activities that also entails watering andcompaction (Díazde León, 2015).These activities are projected to take a huge chunk of time owing totheir demanding nature. They would roughly take three days.

Theother set of activities will be the structural excavation,preparation of the concrete (placing concrete, pouring it, strippingforms and curing the concrete) and the reinforcement of the preparedconcrete. These are activities that would also take more time andwould be allocated three days as well.

Atthis point the final set of activities will be the making of thefloor slab that is reinforced with rebar, the column and foundationslab also reinforced with rebar. Others are the general activitiesthat are supervision and cleaning of the worksite.

WORK SCHEDULE

Activity

Description

Predecessors

Duration

A

Site selection and material to the site

2

B

Clearing, filling and finishing

A

3

C

Structural excavation

B

1

D

Concrete preparation and reinforcement

C

2

E

Foundation and column

D

1

F

Garage parking floor

E

1

G

Inspection and finishing

F

1

Figure4: Working schedule

References

Díazde León, A.&nbspForensicEngineering 2015&nbsp(1sted.).