Preparation of BILL OF QUANTITIES

The BOQ is the list of the various components of a building, in a logical order.The list gives a detailed description of each component and the quantity of it measured by the quantity surveyor.These items when collected together into a bill, form what is called as a Bill of Quantities.so BOQ fully describes and accurately represents the work to be executed, including the obligations required of the contractor, and so provide a uniform basis for the preparation of competitive tenders.

Functions of the BOQ

1. Tendering
2. Valuation of interim certificates
3. Valuation of variations
4. Cost analysis of future users
5. Construction plan and monitoring
6. Final accounts

Contents of BOQ

• Preliminaries
• Preambles
• Measured quantities
• Provisional sums
• Prime cost sums
• Day work schedule 

Advantages & Disadvantages of Steel Buildings

Steel is a combination of Fe and C (Carbon).Carbon Percentage is around 0.2%-2.14%.Fe is a very flexible material and Carbon will reduce the flexibility. Zn,Na,Al also can be mix with Fe but Carbon is the cheapest one. 

Advantages of Steel Buildings

1. Recycling

•      Steel components generate minimum waste and all light gauge steel construction materials are 100% recyclable.

2. Strength and durability

•         Steel framing material is significantly stronger than wood. No other construction material can match the superior strength and durability of steel. Steel has the highest strength-to-weight ratio. Strength and non-combustible qualities of steel enable it’s framed structure to resist fires.

3. Termites

•     Steel is simply impervious to termites and other damage-causing bugs and pests. Steel studs are impervious to insects, rot, and mildew.

4. Climate and condition or dimensionally stable

•         Steel will not crack, shrink, splinter, creep, split, warp, or swell.

•      Individual members of a wood-framed building react differently to climate changes. This wood movement may include expansion, contraction, warping, twisting, etc.

5. Cost effective

•      Steel studs are non-flammable, and won't add fuel to a fire.  Insurance rates for steel homes are often cheaper than wood framed homes.

6. Weight

•      Steel components weigh 60% less than wood. A 2000 square foot home requires only 6 tons of steel compared to 20 tons of timber.

•        Steel is light in self weight and very strong; transportation and site handling are easier.

7. Always straight

•     Unlike lumber, light steel components are always straight, this allows for a flat wall every time.

•         Steel stays straight and true, while wood may warp or crack.

8. High structural efficiency

•         Steel components allow for longer spans with less post supports.

•    Steel has one of the highest weights to strength ratios of all construction materials. This strength advantage means better design flexibility, wider spans and better material usage.

9. Steel is a “green” structure environmentally friendly material

•         Steel is environmentally friendly.

•   Steel-framed housing dramatically reduces the amount of trees consumed for residential construction, thus conserving one of nature's most precious resources. The only wood products used for light gauge steel construction are plywood sheathing and door and window trim components.

10. Only simple site assembly is needed.
11. Steel construction is fast. There is virtually no "wet" work.
12. Design is easy in seismic conditions.

Disadvantages of Steel Buildings

1. In many areas it is difficult to find framing crews that are trained in light steel construction.  This disadvantage usually raises the overall project cost.                          
2. Because Steel studs are a poor insulator, they suffer from thermal bridging which reduce the overall wall insulation value.                                                                            
3. Even though steel components will not burn, they will actually fail (collapse) before a wood component in a house fire.                                                                                      
4. Steel is an excellent thermal conductor requiring additional exterior insulation or thermal breaks to overcome this disadvantage. Thermal conductivity is probably the most serious of steel's disadvantages.                                                                              
5. Finding steel roof trusses is difficult in most areas so it is common to use wood roof trusses (and sometimes floor trusses).                                                                             
6. In addition to the labor training required to convert to the use of steel, builders and laborers must obtain some new tools not presently used by carpenters. The combination of additional training and tools translate to increased costs of construction for a short period of time.

Failure of Steel

   

         Ductile failure                                                                                        Creep

               Fatigue failure                                                                                   Impact failure

                                          CONCRETE

As a Quantity Surveyor he must have some knowledge about Materials that have been used in Construction Industry.Concrete is one of them. It's Consisting with,

• Cement
• Water
• Fine aggregate (sand)
• Course aggregate (stone chip or boulders)
• Admixtures

Roles of each Compositions

1. Cement – react with water to form a “glue” to hold the concrete (primary binder to joint aggregate into a solid mass)
2. Water – react with cement to gain the strength (hydration)
3. Aggregate – Make concrete stronger, more durable, less cost and reduce shrinkage of  Concrete                                                                                                                                              40mm = Mass Concrete in Road Construction                                                                               20mm = General Concrete work                                                                                                     10mm = Thin Sections, Screed over 50mm thk                                                                                5mm   = Screeds 50mm thk or less                                              
4. Admixture–modify the properties of the concrete such as increase setting time, durability, Workability of fresh concrete,give colour to Concrete

Types of concrete

•   Light weight concrete

 Light weight aggregate concrete

 Cellular concrete

 No fine concrete

•  Aerated concrete

•  Polymer and polymer cement                                                                                                

Light weight concrete

Its advantages are less need for structural steel reinforcement , smaller foundation           requirements,better fire resistant and insulation properties.

      it can be produced in three ways;

1.       By using light weight aggregate – Light  weight aggregate concrete

2.       By introducing gases or air bubbles- Cellular concrete

3.       By removing the fine aggregate- No fine concrete

            Aerated concrete

            It is an environmentally friendly material. These include lime, gypsum, water and a                            expansion agent

            Polymer and polymer cement concrete

            Polymer concrete is a composite material in which the binder consists entirely of synthetic                   organic polymer.There is a substantial increase of cost because of the use of polymer 

             instead of Portland cement.

Stages of Concrete Preparation

1. Batching                                                                                                                                Before concrete can be mixed, the components have to be measured in their correct proportions.This can be done either by volume or weight        
2. Mixing                                                                                                                               
3. Transporting                                                                                                                           
4. Placing                                                                                                                                         It is essential that concrete should be placed in the form-work as near as practicable to its final position and before it becomes  too stiff to work. Concrete is placed in even layers. A concrete layer is placed over before the previous has set           
5. Compacting                                                                                                                                 The purpose of compacting the concrete is to achieve maximum density by removing air voids from the concrete. 
6. Curing                                                                                                                                         After placing and compacting , the concrete should be allowed to set and harden for a particular period under controlled humidity & temperature. This process is termed as ‘Curing’

Properties of Fresh Concrete

1. Consistency                                           The slump test, is the most generally accepted method used to measure the consistency of concrete. The test equipment consists of a slump cone (a metal conical module 300mm high, with a 200mm- diameter base 100mm-diameter top) and a steel rod 16mm in diameter and between 450mm and 600mm long with a hemi spherically shaped tip.                    
2. Workability                               Workability is often considered to be a measure of the work needed to compact the wet concrete             
3. Uniformity                                                                                                                          Degree of homogeneity or state of distribution within the mix                                             
4. Segregation                                                                                                                     Segregation is the tendency for coarse aggregate to separate from the sand-cement mortar.This results in part of the batch having too little coarse aggregate and the remainder having too much.The former is likely  to shrink more and crack and have poor resistance to abrasion         
5. Bleeding                                                                                                                                 The Bleeding is the development of the layer of water at the top or surface of freshly placed concrete  

Properties of Hardened Concrete

è Strength

è Durability

è Fire Resistance

è Acoustic Property

è Alkali Resistance

Factors Affecting Strength of Concrete

è Curing conditions, humidity, temperature

è w/c , (inversely related)

è Aggregate characteristics, roughness, grading,

è Cement type

è Cement content (directly related)

è Mixing water

                                                          FORMWORK

Form-work is required to support the concrete until it attains sufficient strength to support itself.

A good form-work should have the following properties.

• It should be strong enough to resist the pressure or the weight of the fresh concrete and superimposed loads, if any.
• It should be rigid enough to retain the shape without excessive deformation.
• It should be economical in total cost.
• It must be easily removable.

Materials for Formwork

The main items which affect the cost of formwork are materials and labour in fabricating, erecting and removing the formwork. Materials used for formworks are decided by economy, requirement or a combination of both. most commonly employed materials are timber, plywood, Steel and Aluminium (nails, bolts and form connectors, etc). If the materials can be used more than one time, the cost per use may be relatively low.

Removal of Formwork 

The formwork may be removed after the expiry of following periods under normal conditions when ordinary Portland cement has been used when rapid hardening cement is used, the above period is greatly reduced.

Formwork for Columns

 Column form work may be out of timber, steel or fiber-board. The four sides of the Box are held in position by the use of wooden Blocks, bolts and yokes. A wash of water should be given to the inside of the formwork just before starting the placing of concrete.

The beam formwork

Consists of a three-side box which is supported by column forms or cross members called head trees.

Wall Formwork

The wall formwork consists of timber sheeting supported by vertical post and horizontal Wales. Small pieces of timber known as spacers may be used and they are to be removed as the concrete 

Formwork for Staircase

It consists of stringers, sheets, joists, bearers and vertical posts. Stair is designed to be self supporting longitudinally from floor to landing or across wall to wall. The sloping slab is supported by planking which is further supported on battens and posts. To give shape to the stringers, inclined planks are fixed.

                                                        

AutoCAD

How to take measurement in Horizontal or Vertical line

Before taking the measurement it is better to turn on the object snap tool.Right click the tool and select the settings.after that tool box will appear.I will recommend to select only end point,mid point,nearest point and perpendicular point.

                               

Then select Annotate in the tool bar and select dimension.Select first point and then second point and take the dimension.

                                                                                

If you want to change the unit, you can go to the dimension style by typing dimstyle and hit enter.After that below Page will appear.Go to the modify and Select Primary units.Then you can change the unit format of the measurement and save it.If you want the unit in feet & inches choose architectural and need in millimetre choose decimal.You can change all the style of dimension such as text colour,size,precision and etc.  

                          

                                                                                                                                                       How to Measure the Area                                                                                                                                                                                                                                                                          

Before taking the area you must Draw a Polyline above the shape.After that select the polyline,type list Command and hit the enter.Then you can see a page like this.In that page you can see the area and length of the selected shape.this method can be use to not only for a shapes but also for a lines also

                                                                                                                                                                                                                                                             

Who is a QUANTITY SURVEYOR

       
QUANTITY SURVEYOR is a Professional concerned with Construction cost & Contracts with in the Construction Industry.He has nr of Roles & Responsibilities such as,

1. Preparation of BOQ
2. Preparation of Tender Document
3. Preparation of Contract Document
4. Estimating
5. Bid for Projects
6. Rate Analysis
7. Preparation of Interim Payment Certificate
8. Preparing Variations
9. Material Ordering
10. Final Account
11. Assessment with claims
12. Value Engineering
13. Risk Analysis
14. Cost Planning
15. Cost Controlling
16. Life Cycle Costing
17. Procurement Arrangement