CRACK TREATMENT OF THE ASPHALT BINDER COURSE

Main Break Water(MBW) access road occurs several cracks on the asphalt binder course. The road cracks are monitored and investigated with specialist from RDA Research & Development. This report describes the reason and remedial method of the cracks based on the investigation and consultation.

MBW access road structure consists of fallowing cross section and the core samples have been taken on the cracks.

According to core sample data, can be observed that the crack was started from CBM and reflected to the binder course surface.

CRACK INVESTIGATION

The crack survey carried out for the entire road and investigation detail summarized as an attached sheet. Core samples were taken from the jointly selected locations with the engineer. MBW access road cracks were categorized into two types based on crack surface appearance.

• Transverse cracks
• Longitudinal cracks
• 
  

Transverse cracks

Transverse cracks were occurred as a perpendicular to the road center line. These cracks are reflecting from the CBM layers.

• According to core sample data, can be identified the fallowing crack types was happened.
• Some of cracks were occurred from CBM 2^st layer and reflected to the binder course surface.
• Other cracks are started from CBM bottom layer (1^st layer) and reflected to the binder course.

Longitudinal cracks

Longitudinal cracks were occurred as a parallel to the road centerline and which was happened due to the reflection of the CBM longitudinal joint. 

PROPOSAL FOR REPAIR OF CRACK

Proposal of the crack repairing method is introduced by specialist from RDA Research & Development.

Three conditions for reflection cracks on CBM :

• Cracks in the base layer must be wide enough to generate stress conditions in the asphalt surface.
• There is no method available to relieve the stress concentrations.
• The asphalt is brittle enough to crack due to upwards propagation of the stress concentration.

In most cases, reflection cracks are narrow (less than 3mm) and will not adversely affect the performance of the pavement. But all the cracks on MBW access road will be treated to prevent from the possibility of propagation.

As per the specialist’s proposal, Geo-Fabric material will be applied along the cracks of the binder course before laying the wearing course in accordance with manufacturer’s instructions.

CRACK REPAIRING

Proposed Material

• Polyfelt (PGM-G 50/50) to be used, material details is in Appendix

Manpower

• Supervisor
• Skilled Labours
• Unskilled Labours

Sequence

Methodology

Identify the crack locations and properly cleaning by air compressor.

Bring the notification to the site representative of the Engineer.

The binder surface is thoroughly cleaned and free from all the traces of dust and any of unsound materials.

Cut the Ploy paving Fabric (PGM 50/50) for required length of the crack and 0.5m offset from the crack as following the sketch.

Foundation Part 02

Excavation For Pile Cap

Shoring is provided around the proposed pile cap with 600mm working space. Excavation is carried out up to certain level by using backhoe. Then excavation was carried out manually. Excavation is very difficult below ground water level. De watering system should be provided.

Excavation With Jcb

Shoring Is Provided

Difficulties in excavation below the ground water level.

• Difficult to remove the soil
• Need continuous de watering process
• Density of soil will increased
• Erosion or collapse of the sides of the excavation

Pile Hacking

Pile is casted up to above required level. Then it is broken up to required level. This is known as pile hacking. Top concrete is weaken so pile should be casted above required level. Normally height above required level, it is equal to the diameter of the pile. But during the concreting ensure the concreting whole pile, normally concreting the ground level. Then excavate soil and pile should hacking required level.

 

Pile Hacking Process

Pile was hacked by using Air breaker. Pile hacking can be carried out by using two methods.

1) Start to pile hack from top of the pile.

2) Break at above required level.

Second method is suitable for if large length to be hacked. For other cases first method is used. In second method pile is hacked horizontally up to reinforcement gage at just above required level. Then pile is connected to the crane. Reinforcement bars are cut. And small force is applied horizontally by crane or JCB. At this stage pile should break fully. To reference the pile cutting level the cutoff level marked on existing reinforced bar of pile.

There were used main three of tools to hacking piles. All are working with air compressor.

1. Driller – To making hole on pile, it make crack along the hole

2. breaker - To break the pile components as small peaces

3. chipper - To level the break surface

Pile Breaking With Breaker

Eccentricity Of Pile

After the hacking piles the eccentricity of piles was taken. Actual co-ordinate of the centre of the pile sometimes, which may vary from co-ordinate, which is according to the drawing.

Eccentricity of pile = (Actual co-ordinate) – (co-ordinate according to the drawing)

Determination Of Centre Of Pile

The geometrically method as shown in the figure, pile center was obtained most possible position. Most of times the casted pile or reinforcement cage of pile not in actual circle, but we were take the most probable circle shape in cut surface

Plan view of pile

If pile is regular shape, we find centre of pile by triangulation method.

If pile is irregular shape, we find centre of reinforcement gage by triangulation method.

Pile Caps

Pile caps are usually constructed of concrete to such depth as will ensure full transfer of load to piles, at the same time, resist punching shear. Since it is almost impossibility to bore or drive piles exactly vertical. The pile cap should be large enough in plan to accommodate any deviation in the final position of the pile heads.

Concreted Pile Cap

  Section Of Pile Cap

Pile Cap Re- Design

Sometimes piles are not installed at correct position. That deviation is over to allowable limit that make additional moment in the structure. Due to above problem pile cap dimensions have to re-design. In our site the pile cap F6 2P1A of piles are shifted over the allowable limit. Therefore its pile cap was redesigned.

Re-bar arrangement and spacing between bars are not changed. Additional reinforcement is taken by pro-rata basis from earlier one.

TENDERING, ESTIMATING AND QUANTITY SURVEYING – Tendering Methods & procedures:

Tendering Methods & procedures:

Methods of Contractor Selection:

The selection of a contractor to carry out construction works in a project is a very important matter.

A wrong choice may lead to an unhappy client / contractor relationship.

It also may end up with dissatisfied client and sometimes even with an insolvent contractor.

The client’s professional advisers should find a contracting company;

That is financially stable / and has a good business record.

For which the size of project is neither too small nor too large.

That has a reputation for good quality workmanship and efficient organization.

There are three principal methods for choosing a contractor:

(a) open tendering,

(b) selective tendering,

(c) nomination.

Open Tendering –

Initiated by client’s architect/ quantity surveyor advertising in newspapers and/or inviting contractors to apply for tender documents and to tender in

competition for carrying out the work. Usually a deposit is required to discourage irresponsible applicants, the deposit being returnable on the submission

of the tender.

Advantages –

There can be no favoritism.

Can get the maximum benefit from competition.

An opportunity is provided for any capable firm.

Disadvantages –

There is a danger that a firm inexperienced in preparing tenders may submit the lowest tender.

There is no guarantee that the lowest tenderer is sufficiently capable or financially stable.

Total cost of tendering is increased.

Selective Tendering –

A short list drawn up of contractors who are considered to be suitable to carry out the proposed work.

Names may be selected from an approved list or ‘panel’ maintained by the client.

It is recommended that the number of tenderers should be limited to between five and eight, depending on the size of the contract.

If the firms on the list are all reputable, well established and suitable for the proposed work, then the selection is resolved into a question of price only.

Advantages –

Ensures that only capable and approved firms submit tenders.

Reduce the cost of tendering.

Disadvantages – 

Cost level of the tenders will be higher due to less competition and also due to the higher caliber of the tenderers.

Nomination –

Sometimes referred as ‘single tendering’.

It is a special case of selective tendering where the short list has only one name.

Used when the client has a preference for a particular firm, often because it has done satisfactory works for him before.

Competition is eliminated and that will lead to a higher price.

Contract sum will be arrived by a process of negotiations.

When a large project is to be carried out in successive phases, a combination of selective tendering and nomination is employed –

this is sometimes called “serial tendering”.

*The contractor is chosen for the first phase by means of selective competitive tendering.

*The accepted tender forms the basis of payment for the resulting contract.

*The tender is also used for the second and later phases, provision being made for so doing in the initial contract by the inclusion of a

formula for updating prices.

The purpose of serial tendering is to gain the benefits of continuity.

*The contractor for the first phase of the project will have his site organization set up, his offices and storage huts, etc., already in

use and plant of various kinds on the site.

*When the second phase commences, these facilities will be already available.

It allows smooth transition with less additional expenses.

*In addition, the contractor’s workforce will be familiar with the details of the construction after building the first phase, and it helps to

work more speedily and efficiently.

     Negotiated Contracts:

1. This may be done using bills of quantities / schedules of rates.
2. The rates and prices are discussed and agreed until eventually a total price is arrived.
3. Usually negotiation will be conducted between the contractor’s quantity surveyor and the project quantity surveyor.
4. One party will usually price the tender document first of all, then the other party go through the rates and prices ticking off those which are acceptable.
5. When agreement is reached, a contract will be entered between the client and the contractor.
6. This process is sometimes called Single stage negotiation.

In this procedure, absence of competition usually results in a higher price.

Therefore, with a view to gaining the benefits of competition as well as the advantages of negotiation, a process of limited competition for the

selection of contractor, followed by negotiation with him on the details of his tender, is used.

This process is usually known as two-stage negotiation.

In the first stage tenderers are informed of the second stage intention and are asked to tender on the basis of

Schedule of rates consisting of the main/ significant items only.

Prices for the main preliminary items;

Construction program showing estimated times.

Labor and plant resources/ construction methods.

Details of all labor rates / material prices / discounts, etc.

Discussion with each of the tenderers may be conducted in order to clarify their proposals.

Having selected a contractor at the end of the competition stage, negotiation will follow on the basis of a detailed tender document as in

single stage negotiation.

Two-stage negotiation is the method normally used to select a contractor to carry out management contract, in which the general contractor

does little or none of the construction work himself but organizes sub contractors to do the work.

Tender Document:

The number and nature of tender documents will vary with the type of contract.

They will include some or all of the following;

Conditions of Contract:

This document sets out the obligations and rights of the parties.

1. Bills of Quantities.
2. Specifications.
3. Drawings:

Normally general arrangement drawings will be provided.

Tenderers are not normally given working drawings.

Full descriptions of the work are incorporated in the bills or specifications.

Tenderers are informed that they can inspect drawings not supplied to them at the architect’s office.

Form of Tender:

This is a pre-printed formal statement, often in the form of a letter, in which tenderer fills in, in the blank spaces, his name and address and the sum

of money for which he offers to carry out the work shown on the drawings and described in the bills of quantities or specifications.

Return Envelope:

Each tenderer should be supplied with a pre-addressed envelope clearly marked “Tender for  - name of the project”.

This will ensure that tenders are recognized as such when received and will not be accidentally opened.

Tenderers should be asked to acknowledge in writing receipt of the tender document.

Tendering Procedure:

Preliminary Enquiry:

It is recommended practice (not always followed) to send, about a month beforehand, to each of the firms from whom it is proposed to invite a tender, a

preliminary inquiry, to ascertain that they are willing to submit a tender.

This avoids the situation of contractors declining to tender, or if they prefer not to decline, submitting a ‘cover price’, i.e. a price which is high enough to

be well above the lowest tender.

Sufficient information about the project should be given in the preliminary enquiry letter to enable each contractor to decide whether he is in a position to

meet the terms.  

Period for Preparation of Tenders:

It is important that tenderers are given sufficient time to make all necessary enquiries from suppliers, sub-traders, etc. and the date for return of tenders

should be fixed so as to allow for the amount of work likely to be involved in preparing tender.

Four weeks is recommended as a minimum period, although it is possible, in exceptional cases, for less time to be adequate.

A time of the day should be specified as the latest time for tenders to be received on the date fixed.

Any tenders arriving later should be returned.

Parity of Tendering:

It is important that all tenders should be based on the same information.

All the tender documents must be identical.

A tenderer may telephone the architect / project quantity surveyor about an item in the bills of quantities or a clause in the specification. He may question

the accuracy of a quantity or unavailability of a specified material in the market.

Such queries must be answered and must be dealt with promptly.

But, whatever the reply given to the enquirer must be communicated to all other tenderers, immediately by telephone and then confirmed in writing.

The same procedure must be followed if an error is discovered or if it is decided to extend the time for the receipt of tenders.

The tenderer should be asked to confirm in writing the receipt of every written communication of additional or varied information.

Opening of Tenders:

A formal procedure should be followed for opening tenders to eliminate any suspicion or irregularities.

No tender must be opened before the latest time for submission.

As little time as reasonably possible should be allowed to elapse before opening tenders and they should all be opened at the same time.

Notifying the Tenderers:

As soon as possible after opening of tenders, all tenderers should be informed, then each tenderer will know whether his tender is successful or not

and be able to judge his future commitments.

This is a duty of often falls to the project quantity surveyor.

TENDERING, ESTIMATING AND QUANTITY SURVEYING – PRINCIPLES

• Quantity Surveying Organization & Practice;
• Office & Staffing Organization;
• General procedure in Quantity Surveying office;

Essential to keep the office well organized, so that work is dealt with satisfactory and logical manner.

• At the start of a new project;
• all architect’s drawings should be stamped with the office stamp and the date of receipt.
• All drawings should be listed and carefully examined.
• Figured dimensions on the drawing should be checked, and any omitted dimensions calculated and inserted on the drawing.
• If walls and partitions are coloured in different colours, according to type and thickness, it is easier for identification.
• Any queries on the drawings should be entered on query sheets for clarification from Architect.
• If quantity surveyor is unfamiliar with materials, components, etc, he should obtain full particulars from manufacturers.
• If possible, same group of quantity surveyors should be arranged to take all works from inception to completion of the project.
• This procedure enables the staff to obtain wider and more interesting experience.
• It is likely to result in improved efficiency through greater familiarity with all the details of the scheme.
• It is sometimes the practice on large projects to subdivide the taking off work between different quantity surveyors / separate groups.

E.g. subdivision could be:

• Structure of the building,
• Joinery and finishes,
• Services and external works, etc.
• Some times whole of the taking off works will be undertaken by a single group of staff under the supervision of a Senior surveyor / team leader.
• After the draft bill is prepared,
• examining and editing by a partner / senior surveyor.
• The final documents will be dispatched to tenderers, with a covering letter stating,
• the date / time / place where the tenders are to be delivered.
• Where / when the contract drawings can be inspected.
• How the contractor can visit the site.
• Request for acknowledgement of receipt of document.

Construction cost management – much more important part of the present day quantity surveying works. This includes;

The keeping of extensive cost records of all passing through the office.

This will assist with cost forecasting of future projects.

Preparation of accurate cost estimate is always form a vital part of the work of a quantity surveying office.

Cash Flow Projections:

• The client will need to know the likely sums which he will be required to pay the contractor and when they will occur.
• To meet this need, the quantity surveyor will prepare a schedule of the likely amounts due and their timing.
• (for this he will use contractor’s approved program of work which submitted with the tender / shortly after its acceptance)
• but any design variations by the architect can result in changing both to the amounts due and their timing.
• If these changes are very significant, it should be brought to the attention of the client.
• Delays in execution of the contract work will also affect the amount and timing of payments.

Financial Reporting:

• client should be fully informed by the quantity surveyor on all cost aspects of the project. (Particularly where changes are made to the design / sequence of the work during their construction)
• normally the quantity surveyor is notified of such changes before they are implemented on the site.
• Therefore he has adequate time to prepare detailed cost comparisons and can inform the client of the likely cost consequences of the changes – including the probable impact on other sections of the work.
• When more detailed information becomes available on variations, mainly from measurements, quotations or day works, the quantity surveyor can refine his original estimates and update his financial reports to the client.

 

Quality Assurance in quantity surveying:

Quality assurance (QA) is a systematic way of ensuring that organized activities are implemented in the way in which they are planned.

• Its main purposes are;
• To meet client requirements.
• To meet industry requirements.
• To improve management control with regard to the quality of service.
• To increase efficiency.

Quality management policy statement of an international quantity surveying practice indicates;

• To provide the highest possible standard of service to clients,
• To operate whenever possible quality management system which has been developed in accordance with BS 5750 Part 1 for professional quantity surveying services.
• To ensure that the personnel using reasonable skill and care, work in accordance with the procedure detailed in the quality manual.
• To periodically prepare quality reports and reviews of procedures in order that the quality management system may be improved.
• Provide facilities for clients’ representatives to verify compliances with the quality management system.

General Office Management:

• Secretarial and clerical staff should be given clearly defined duties and responsibilities.
• At the same time be encouraged to work as an effective team with sense of loyalty.
• Telephone messages should be clearly recorded and the messages relayed to the person concerned as quickly as possible.
• Letters should always be drafted with care; for that following guidelines observed.
• There should be no possible doubt as to the true intent and meaning of the letter.
• The wording should be as simple and concise as possible.
• Where extensive information is entailed, advisable to send a brief letter accompanied by a detailed report / schedule.
• Reports are normally subdivided in to;
• Introduction,
• Body of the report,
• Conclusion and recommendations.
• Technical terms should be avoided as far as possible when writing to lay persons.
• Letters must be free from grammatical and spelling mistakes.
• Impersonal languages should be avoided.
• E.g. “I / we consider” is much preferable to “it is considered”.
• When dispatching correspondences, a check should be made to ensure that all relevant enclosures are sent with the letter.
• Careful checks should be made to ensure that the correct letter is inserted in the correct envelope.
• All incoming correspondence and copies of outgoing letters must be carefully filed in a system that permits easy retrieval.
• All correspondence should be filed in date order, with the most recent at the front of the file.
• Letter references often include the project reference and the initials of the writer and typist.
• Minutes of meetings, site records, project details, cost information and other supporting data must be carefully preserved.
• Another important section of any quantity surveying organization is the information center or office library containing trade literature, reference books, acts of parliament, standards and specifications, etc.

Professional Ethics, Standards and Conduct:

Professional Ethics and Standards:

The RICS (1994) believed that ethics should be taught as part of university surveying degree courses. It could lead to higher professional standards and enhanced attitudes to the need for greater honesty, dedication, care and trust in all professional relationships with clients, other surveyors and general public, and the avoidance of making decisions which are morally wrong.

All members have a moral duty of care when dealing with clients and their affairs. And to exercise the utmost honesty and integrity in all their dealings. Clients can rightly expect that professional men and women will possess a reasonable measure of competence and skill. RICS rules of Conduct states: Members of the institution shall discharge their professional duties to their client and to wider public interest in accordance with the objectives of institution.

Members shall:

• Ensure that where there is conflict between the interest of the member and that of the client, the interest of the client shall prevail, unless it is at odds with the wider public interest.
• Ensure that they perform their duties:
• With integrity and honesty,
• competently and diligently,
• by adopting personal and professional standards.
• any member must not hide any relevant facts from the client of which he should be aware of.
• Chartered surveyors have to fulfill their client’s high expectations of their standards, which in real word have to be balanced against the surveyor’s price levels and the value for money that they provide.

Setting Out

 

Setting out is done to locate the position of the structural parts as in the detailed drawing with geometrical construction. The setting out is done to locate pile position, pile cap, column position, beam bottoms and slab boundary in the site.

Setting out is done with the reference to grid lines. When the grid lines are given in the drawing, setting out are done with reference to these grid lines using any type of technique means Suring angles or distances. In the absence of any kind of grid lines detail first the location is at the site. Considering other requirements of usage and setting out is done with reference to any base line or permanent structure. In site the base line has marked in the side of the Moors road and all grid lines are marked on around of the boundary wall.

The accuracy of setting out is depending on the usage and for which the structure is used. The method of setting out is depend considering the accuracy required and the measuring instruments availability, there are two types of measuring instruments one is measuring angles and other is by length the whole setting out work is done either by measuring angles or by measuring lengths or by measuring both. Setting out of a pile position and foundation is very important and the accuracy of the whole structure is depending on it.

Setting out was started from ground floor and continued to the other floors. If error is not allowable setting out has to be done again.

 

IMPORTANCE OF SETTING OUT

Setting out is providing pegs, levels, profiles and other information necessary for carrying out construction works. The results of setting out should be the true interpretation of the information given in the drawings.

Setting out should always have independent checks for readily detecting any errors and well recorded methodical approach for future reference. The basic requirements for setting out are the measurement of distance, the measurement of angles and the establishment of levels.

LEVELING

A temporary bench mark is established at the site for the datum of all the leveling work of the building. But in site for the easiness the 1000 mm off line of ground floor finishing level is marked on all around the land boundary wall. It can be get anywhere in site as close reference level. The ground floor finishing level is ± 0.00 in all drawings levels are given from the ground floor finishing level.

All the excavation work had to be done according to the levels given in the drawing. This was essential since all the payments for excavation and back filing were done only after taking site measurement of the excavated area and the levels happened to be more or less the same as those in the drawings.

All the slab and beam work had to be done according to the levels given in the drawings. By tightening and loosing the support jacks the correct levels can be achieved since middle part of the slab can be sag due to the weight of the concrete, levels of the middle part of the slab were established 5 mm higher.

SETTING OUT OF A COLUMN

In column setting out first the corner columns are aligned using plum bob and according to the dimension of the column sections and the centerlines are marked. Then according to the detailed drawing other position of the column centerlines are marked. After locating the centers the centerlines are marked on a cement grout base to avoid disappearance of the marks. Then kickering is done at column section dimension to locate formwork of the column.

But if there are any reinforcement bars straight to the centerlines of a column, then it is difficult to mark centerlines of that column. Then at this situation edge lines are marked instead of centerlines. It must be carefully noted that, the dimension is half of the linear face dimension lesser than the centre to centre dimension.

 

MARKING COLUMN CENTRES

• Setting out of columns is a main task.
• First the theodolite is stout over a base point and bisect a target set or another base point and clamped.
• Then nails are driven at different locations along the line which is described by the vertical cross hair of the telescope, to obtain the grid line on the floor.
• Then the line is marked using an inked thread holding between nails the lines perpendicular to the base line is also marked as required.
• The distances to the centre of each column from two perpendicular grid lines are calculated and noted down.
• Finally, by direct measurements from grid lines are marked to give the column centre.

Store Management

Store Management is an important aspect in a construction site. Material requirement should be calculated and the orders should be placed in advance so that material is readily available when work begins. The site stores in this site mainly manage receiving, issuing and storing of material and the maintenance of plant & equipments.

Characteristics Of A Well Managed Store

Availability of materials whenever required

The storage quantity should neither be too much as it would increase the storage cost and the material may get deteriorated. On the other hand the stock levels should not be too low as a material shortage may lead to delays of the project. The optimum may vary from site to site, item to item or supplier to supplier. Yet it is a good practice to keep one week’s requirement in stock.

Material should be stored in such a manner that they are easily accessible, not subjected to environmental damages and would not obstruct the site traffic.

Using the FIFO basis in issuing materials whenever possible

A properly maintained recording system facilitating the preparation of usage reports, regular stock counts, monitoring the inward and outward movements.

Documents maintained in the system

Goods Received Note (GRN)

After receiving a stock of material the Store Keeper would issue a GRN acknowledging the receipt. This has to be authorized by the project engineer. The updating of the stocks ledger and the preparation of the weekly reports are done using this.

Gate Pass

A gate pass is raised every time a site vehicle goes out of the site. This is issued either by a storekeeper or by an engineer. Though the stores do not raise this strictly a gate pass would restrict unauthorized stock transfers.

Material Requisition Note (MRN)

The subcontractors and any other person have to produce a MRN to get material from the stores. The form has to be authorized by the supervisor in charge of the work. To facilitate the monitoring of the material usage the supervisors keep a record of all the material issues authorized by them and produce a summary to the engineer in charge. The details of all the issues are transferred to book on a daily basis and a summary is used to update the Bin cards.

Purchase Order / Request Order

When a particular work has to be started the engineer in charge of the work prepares a list of material required. If the list includes items that are not in the site stores it will either be transferred from another site or purchased by the head office and transferred. This requisition is placed by through a purchase order prepared by the engineer and includes all the details required to place the order.

Bin Card

This is maintained in the stores to record the movements of the stock level of all the items. A bin card is maintained for each item in the site. The purpose of a bin card is to record the receipts and issues and the stock level of the item at any moment can readily be found from this. The bin cards in this site serve the function of a stocks ledger. The updating of this is done using the entries of the material issues book.

Invoices

When a supplier directly supplies goods to the site he will produce a copy of an invoice raised by him. The invoices are filed and sent to head office for billing. The details are used to update a book of receipts as well as weekly material progress reports.

Material Storage.

More attention should be given to the material storage within the site premises. This should be done in order to prevent any damage, wastage and to maintain working delays. Each and every item should be labeled for proper identification and also to handle easily. These labels should contain a brief description such as the date of purchase, type, size etc. Every item at the store was insured. Also it should be easy to handle and transport the materials to the required job from where it is stored.

Storing Of Fine & Course Aggregates.

Storage of both fine and course aggregate should be related to the mixer position. And also it should be considered the transport facilities to that place and the area to be used.

The required concrete amount & the number of deliveries to the site will determine the size of the storage spaces. Various sizes of Course aggregates should be stored separately to avoid mixing them together.

Storing Of Cement.

Cement should be stored on a stage raised above the floor level to avoid hardening due to dampness of the floor. Cement bags should not be stored one over the other more than 8 bags. It is better to keep about 9” distance between cement stock and the walls. Cement stocks should use before 4 months. When using cement it should issue earlier stocks previously.

Storing Of Reinforcement.

Care should be taken when storing steel (reinforcement) to avoid mixing them with different sizes of steel bars and different sizes. The different diameter of steel bars & various types were placed in separately on racks. They should be prevention form corrosion & free oil and mud. For this purpose reinforcement should be stored in a covered place.

Storing Of Tools.

Tools and equipments should be stored with security. This is because of these items are small and valuable. Workers use tools and small equipments sequently. Therefore these should be stored inside the stores where it can be reached easily. These tools and equipments should maintain well otherwise they cannot be used for a long time.

Machinery At Site

Machinery Use At Road Project

There are many operations to be done in a construction project. Such as demolishing excavation of Earth, transport of material, cleaning etc. for that, most of these operation machines are used Different machines are used difference purpose.

The selecting of machinery is done accordingly

• Nature of work
• Method of construction
• Time allowed for the work

Earth Moving Equipment

Almost all civil engineering project, start with earth excavating work on earth filling even for project where only earth filling is involved. It is necessary to excavate earth from other location for that various types of machines equipment general used such as,

Excavators

Excavators are very popular earth machine equipment it is mainly using for demolishing work & excavation. There are two types of the feet excavators.

• Hydraulically powered excavators
• Cable excavators

Hydraulically powered excavators

The conventional shovel excavators are being improved upon to provide all hydraulic operation. The advantage of powered excavators over the conventional shovel excavators are given below. The dead weight of the bucket or the boom does not come in to play. The power for excavators is derived from the trust of double acting hydraulic Ram. As the result of this the weight of the machine is reduced the rely increasing the powered, weight rate. Because of better power, weight ratio the machine can operate on surface like rock, frozen clay, sifts or boggy Soil. It is efficient & easy to control & give a shock tree operation. It reduces the service cost & operation cost.

Motor Grader

The motor grader is equipment used for leveling & finishing earth work It is particularly suited for maintenance of earthed roads The various attachments of grader are given below

The Blade : It is cured like the door blade & is fitted with replaceable edges on the sides & at the bottom.

The clarifier : It is a tool loosening hard soft. It can be attached in the front or in the rear of the machine

The Elevator : This helps the grader to pick up the cut material. This picked up material. Dropped over an inclined belt conveyor The. Attachment conveyor transmits the material in to carrier unit

Rollers : There are attached to there of the grader to consolidate the graded surface. For grading the machine mares forward & the steering is controlled by the steering wheel.

The following operation can be preformed the grader:

• Grading
• Spreading
• Side crowing
• Road cutting
• Bank dressing
• Mixing material

Backhoe Loader (J.C.B)

This type of machine is basically built up around a heavy duty industrial tractor with special purpose chassis. The engine is a water closed diesel of Approximately 60 H.P The front-end backhoe – attachments are fully hydraulically pearled

The front end loader attachment is suitable for loading tucks & tractor frailer etc. from stockpiles. It can also be used for light duly escalation jobs,

Knelling & maintenance of the road should be etc.

The front-end share has a capacity of 0.9 m3 & with a maximum loading height of 3.2m

The backhoe loading attachment is especially useful for cutting & cleaning work, earth spreading work, drain & culverts & medium duty digging jobs

The maximum digging depth is 4.3m & the maximum reach at the ground level is 5.5m with stander arm.

JBC Backhoe Loader

Earth compaction equipment

Earth compaction is one to the most important civil engineering construction processes. Encountered in the fled of constructor. For that various type of machines equipment used in our site such as, In the site, soil is compaction by using following mentioned

Tandem, double drum (ride on)

Two drums exert the compaction effort, one drum behind the other they are also available in rigid articulated frame

Double drum, walk behind

The compaction effort is erected by two drums & this is also available both in rigid & articulated frame In the rigid frame type the chassis of the frame of the machine is made as a single rigid unit. In articulated frame type the chassis or the farm is made of two units & these two units are pirated at a point between the two axles of the machine, Such that the frame could rotate in a horizontal plane through the pivot. One of the main advantages of the articulated type is that, such a machine can turned in a small area than a rigid frame type.

Double Drum

Pneumatic tired rollers (PTR)

Pneumatic tired roller are available in varying size form I tones to 200 tones. These may to tow or self propelled. These each axis consist four to Nine types. The axis are arranged in such a way that the gaps in front wheels are covered by rear wheel s this priding a complete coverage. Pneumatic tired rollers are used to compact sugared asphalt work bases of airfields & some times in earth dams.

Pneumatic Tired Roller

The compacting ability of this type depends on

• Air pressure of tires
• Width of tires
• Number of tires
• Weight of the unit

In recently developed models the type pressure can be changed without a topping the machine, thus varying the computing ability.

Rammers

Rammers are used to compact soil in restricted small areas. The most common type in the frog rammer. The comp active force is generated by dropping weights the weight of rammers vary from 70 lbs to 3cwt. There are frog rammers weighting up to one tone they are operated either by interval combustion engines or by pneumatic power.

Rammer

Vibratory Rollers

The application of vibratory rollers in soil compaction has become popular in the recent past the first towed type vibratory rollers have been manufactured in the 1940’s. In 1960’s its popularity rose sharply due to rapid advancements made in this connection today vibratory rollers have experienced outstanding success both in granular & cohesive soil’ A rotating out of balance weight produces the vibrations in this type of rollers.

The static weight of the drum applies a compaction force by inducing vibrations of that drum the compaction trace is increased this vibrating force is used to over come fractural & cohesive resistance of the material being compacted, thus aching a greater density.

The vibrating rollers are available with smith drum, sheep-fast drum or with pad foot drum however smith vibratory rollers are not recommended for compacting by a separate engine.

Asphalt Paver Finisher

A paver finisher is a machine for laying asphalt for road construction to give accurate depth, even levelling and good surface finish before rolling. We can use Paver for sub base or ABC work. But our site they have not used. But it is compared to the motor grader method, is found more suitable, because,

• Better and easier respect of levels, both longitudinal and transverse.
• Improved homogeneity of the plant prepared mix.
• Uniform pre-compaction.
• Improved adherence of asphaltic courses.

The paver can easily handle asphalt and all asphalt mixes, coated and uncoated materials, crushed stones and dry lean concrete, in fact all road making materials other than wet concrete. This is the equipment used for paving road surface with asphalt. The paver should be capable of spreading finishing and providing initial compaction of the asphalt mix. It should be able spread the mix to correct lines, grades levels, dimensions and cross section intended, either over the entire width or part of widths as case may be.

Asphalt Paver