CONSTRUCTION QUALITY, SAFETY AND ENVIRONMENT

Assignment 

You have been selected as a project manager for a prestigious high rise building in Mumbai, which will be housing very rich personalities from industry and film world.

Your company management has asked you to formalize Quality Management System (QMS) for interior finishes, Plumbing and prevention of rainwater seepage so that the overall quality standard and image of company is raised.

INTRODUCTION to QUALITY

"The level of quality of a civil work (or part of it) can be measured by the degree of fulfillment of its construction specification and standards with in time.

Construction is one time activity. It affords no second chance of modification, repair or rejection once the construction work is completed.

With the increase in complexity and the size of construction operations, the responsibility for ensuring quality has gradually shifted from worker to supervisor of inspection and later to the quality control department.

It is well known fact that the quality can not be constructed. It has to be designed in to a project system. QMS therefore starts from the design stage itself.

QMS is the responsibility of the project authority. The owner or his representative formulates the policy, determines the scope of the quality planning & management.

STANDARDS & SPECIFICATIONS for making & transport concrete

CONCRETE MAKING STANDARDS & SPECIFICATIONS    

The quality of construction depends upon right material used. the correct method followed and produce end product of acceptable performance. The means of quality control are tests, inspection, supervision and analysis of data etc. Quality tests are conducted in laboratories and inspection and supervision are carried out on the site and data analysis done by experts in the office.

SPECIFICATION:

The standards and specifications for concrete and various ingredients are universally standardized and they are required to be in conformity with same. Indian Standards IS for concrete and its basic ingredients viz cement aggregate coarse and fine, water admixtures and various of concreting, its placement and final acceptance should be as per IS specification.

Concrete Making:     

Raw material for concrete is Cement, Aggregate & Water. Now all the standards and specifications for making of a particular concrete are according to ASTM or BS or IS.Testing is to be done at each level for quality control i.e. in the following order:

Cement test:

Ø Setting time
Ø Soundness
Ø Strength
Ø Fineness and grading
Ø Chemical composition
Ø Specific Gravity
Ø Heat evolution
Ø Water retention
Ø False set
Ø Adulteration

Aggregate test:

Ø Photographic Examination
Ø Grading & surface area
Ø Bulk unit weight
Ø Specific gravity
Ø Absorption and surface moisture
Ø Chemical stability
Ø Resistance to freeze and thaw
Ø Abrasion resistance
Ø Crushing
Ø Impact value
Ø Sampling aggregate

Water test ( for impurities):

Ø Organic
Ø Inorganic
Ø Sulphates
Ø Chlorides
Ø Suspended matter
Ø Hydrogen ion concentration
Ø Seawater
Ø sugar

Concrete testing

The following European standard test methods for concrete have already been published as BS ENs:-

BS EN 12350 Testing fresh concrete

Part 1 : Sampling
Part 2 : Slump test
Part 3 : Vebe test
Part 4 : Degree of compactability
Part 5 : Flow table test
Part 6 : Density
Part 7 : Air content – Pressure methods

BS EN 12390 Testing hardened concrete

Part 1 : Shape, dimensions and other requirements for specimens and moulds
Part 2 : Making and curing specimens for strength tests
Part 4 : Compressive strength – Specification for testing machines
Part 5 : Flexural strength of test specimens
Part 6 : Tensile splitting strength of test specimens
Part 7 : Density of hardened concrete
Part 8 : Depth of penetration of water under pressure

EN 12390 : Part 3 Compressive strength of test specimens has been approved at second formal vote and will be published by BSI in due course.

CONCRETE TRANSPORTING STANDARDS & SPECIFICATIONS:

Ø Moisture Content
Ø Segregation
Ø Setting time

SQC:   

Statistical Quality Control is based on data calculated with all the specifications so that to get the relevant workers either skilled in different works or unskilled to transfer the load etc. Which in return would give quality in the project.

 INSPECTION & CHECKLISTS:

Why are they:        

Preparation of inspection and checklists are very important at each stage to control the quality work in time also. If no inspections or checklists are prepared then there may be a blunder in construction either in specification or in structural details.

Checklists

are prepared for the record of inspection done at different stages. To prepare checklists, is an essential and legal for any type of work. Checklist of all services – sanitary fittings, Electrification work- wiring, surface and conduit wiring, Air Conditioning, cable laying, Ducting.

How much use is made of them:

Use of an inspection or checklist could be after a short time or along time period if any uncertainty happens. At that moment the authorities can calculate the conditions that what could have been happened on disaster time and that where was the fault.       

In my experience & opinion:

There should be regular inspections and preparation of checklists at the start of the event, then in midway of the activity and at last and at the end of the event.

HOW TO ASSURE QUALITY:   

Assurance of quality is done at managerial level with the use of MIS having support system at each level. For the given project the following authorities would give the assurance:

Ø Architect
Ø Interior designer for specifications
Ø Civil engineer (Structural)

CREATING QUALITY ASSURANCE ORGANISATION/UNIT AT THE SITE

Person/Officers- their qualifications & experiences:

Building In charge with a min qualification B.E. Civil and an experience of 10 yrs in the building industry
Site Engineer with min qualification as diploma in civil engineering
Surveyor with min qualification as diploma in civil engineering
Resident Architect with min qualification as B.Arch.

Functions & Duties:

Every day development at the site for the various jobs need to be checked as per the bar chart submitted by the builder at the beginning of the activities. Everyday the surveyor will go at the site and measure the various quantities of the items /jobs done. After noting down he shall handover the same to the site engineer employed. Site engineer shall accordingly go to the site, check the quality of work and can recheck the detail of the quantities submitted to him by the surveyor. This shall continue for a week .At the end of the week this information shall be made in a tabular form and shall be sent to the building in-charge duly signed by the surveyor and the site engineer. Along with this report will also be sent mentioning the bar chart followed for the jobs to be done.

A representative from the architects firm (Resident architect) shall visit the site at least on the alternative days. Resident architect will check that the details of the design submitted by them, are being followed or not.

Reporting to whom: The surveyor at the site shall submit the detail of quantities to the site engineer.

The site engineer shall make his weekly reports of the works done and the requirement of the drawings needed at site and submit it to the building in charge. 

The building in charge shall accordingly make his own summery of the project and shall instruct the builder and the architect according to the requirement. He shall be visiting the site often or make surprise visits.

 Methods of quality assurance:

Testing of incoming materials: already discussed in specifications and standards for making concrete.

In process inspections & testing: for the quality assurance of the various jobs being done at site by regular visits of the site engineer and the building in charge at different stages.

Testing at finishing stages: At finishing stage for all the different activities, one needs to check the alignment of the internal finishes with the walls and floors respectively. The slopes and the finishes are in compliance with the specifications submitted by the construction agencies.

Penalties for non-compliance & incentives for compliance: As I have already mentioned earlier that the bar chart for all the jobs to be done shall be prepared in the beginning of the project. After all the discussions of the builder, architect & building in charge, a flow chart shall be made duly signed by all showing that which job is to be completed at which time. While the construction is going on if the building in charge notices the delay in any activity will send a notice to the concerned agency. It then becomes the duty of the agency to look into the delay and cover up till the next stage of the bar chart. Now if this agency fails to do so, the building in charge/employer shall have all the right to impose the penalty clause according to the agreement.

Conclusion

Civil engineering projects and construction companies have begun to attract the attention of social scientist and management experts. Social scientist argue that it takes more than just SQC and technical skills to produce quality. It requires the restructuring of the project organization the way they think, work and interact. Management expert suggests that quality monitoring evaluation and management information systems should be built in to the construction process at all stages from design to execution.

Books Referred:

NICMAR study material

PMBOK