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*2. Construction Quality 2.1. Construction industry and
Sustainable developmentConstruction facilities occur as a result of
various fundamental motivations/needs: - need for safety (shelter);
- need to provide adequate conditions for various activities
(production, business, education, culture, ....); - spiritual and
aesthetic needs; - protection of environment, etc.
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*Construction industry change (and sometimes) damage
environment:
* The concept of sustainable development Lester Brown 1984 and
U.N. Brundtland Commision 1987:sustainable development is
development that meets the needs of the present without
compromising the ability of future generations to meet their own
needs .
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* For humans, sustainability is the potential for long-term
maintenance of well being, which has environmental, economic, and
social dimensions
The definition reffers to the unitary approach of following
principles:
Present needs for developement;Reducing negative human impact on
the environment and ecosystems;Equity and poverty
alleviation;Preserve the capacity of future generations to meet
their needs
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*In the context of equity principle construction facilities
should satisfy the following three classes of requirements related
to:
* Direct user (client);* Indirect users (other stakeholders:
statutory authorities, rest of comunity);* Environment and future
generations.
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*2.2.The Construction Performance Approach: Requirements,
Performances, Quality
The Performance Approach - is a new (1970) practice which
focuses on a construction asset in order to prescribe desired
results instead of the way and the method to get things done.
It is concerned with what a construction facility (product) is
required to do, and not with prescribing how it is to be
constructed (as The Prescription approach does).
The Performance Approach applies to:- different levels of
aggregation of a built facility (whole building, building elements,
building products/materials);- different life-stages of the project
(design, construction, occupancy, demolition).
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*The Performance Approach main steps
Identifying and formulating the relevant User Requirements
Transforming the User Requirements identified into Performance
Requirements and quantitative performance criteria,Using reliable
design and evaluation tools to assess whether proposed solutions
meet the stated criteria at a satisfactory level.
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*User Requirements (Statement of Requirements) need or
expectation related to the intended product; based on clients needs
and specific activities; document prepared by clients, or in the
verbal statements; initially are vaguely defined, mainly as general
descriptions of the intended facility; are converted/translated
into Performance Requirements (explicit or implicit) by Architect
and Engineer; represent the Demand; the Required performance should
fulfill the Demand; An important part of a continuous process of
communication between clients (demand) and their project team
(supply).
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*
DEMANDUSER LANGUAGERelated to needs Related to own activities
(intended use)
REQUIREMENTSPERFORMANCE LANGUAGE What should have the built
facility to facilitate the intended use Based on technical language
and conceptsPERFORMANCE REQUIREMENTSSUPLYTECHNICAL LANGUAGE Related
to technical solutions How can the requirements be met Specific to
supply chain participantsTECHNICAL SPECIFICATIONSPERFORMANCE
LANGUAGE Predicted and/or measured properties of the solutions
offeredPERFORMANCE SPECIFICATIONS
PERFORMANCE of the BUILDING
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Performance requirements - translate user requirements in more
precise quantitative measurable and technical terms, usually for a
specific purpose.
Performance indicators give details about the way it can be
measured the results against explicit requirements, whether
qualitative or quantitative.
Performance specifications can come from: client; construction
codes and legislation.*
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Target of Performance based approach: matching of user
requirements and performance (specifications) of built
assets.Building performance evaluation is the process of
systematically comparing and matching the performance in use of
building assets with explicitly documented or implicitly criteria
for their expected performance. Performance in use assesment
building performance validation can be done by:- measurement, -
calculation, - expert witnesses.
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The raport between Performance in use and Requirements gives
Quality.
REMEMBER: Quality (according to ISO 9000) = degree to which a
set of inherent (permanent) charecteristics (of a product/service)
fulfils requirements.
Construction Quality (according to Law 10/1995) = represents the
total set of performance in use characteristics of a built facility
in order to fulfill the direct and indirect user requirements,
through the entire life cycle of that facility.
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*EXAMPLE of requirement translation
User requirement Performance requirements
Have meetings with max.- Required space: 3 mp/person;25 people
sitting round- Space shape: L/l 1,5/1;table - Ventilation: min. 30
mc fresh air per person and per hour;- Air temperature: t = 19 22
C;- Noise (due to ext.): max 35 dB;- Lighting level: min 500
lux.
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*Romanian STANDARD about User requirements STAS 12400/1-1985,
Table 2, Anex A define the fallowing requirements:Mechanical
resistance and stability;Safety in case of fire;Safety in use;Leak
protection;Hygrothermal requirements;Air quality;Acoustic
requirements;Visual/Aesthetic requirements;Tactile
requirements;Accessibility;Hygiene;Space functionality and
adaptability;Durability;Value for many (cost effectiveness).
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* Romanian CODE NC 001-1999 regarding explication of User
requirements
Performance requirements - translate user requirements in more
precise quantitative measurable and technical terms, by the use of
a lot/set of Performance Criteria.
User Requirement Performance Requirement = Quality
Requirement
Quality Requirement = qualitative expresion of the building
characteristics (whole building or building subsystems/elements) to
be achieved in order to meet the user requirements, taking into
account a speciffic (for that particular buiding and location) set
of influencing agents/factors.
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*ESSENTIAL REQUIREMENTS
- Law 10/1995 regardind construction qualityidentifies 6
Essential Requirements for construction activity.
- COUNCIL DIRECTIVE of 21 December 1988 on the approximation of
laws, regulations and administrative provisions of the Member
States relating to construction products (89/106/EEC) THE SAME 6
Essential Requirements.
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*
The products must be suitable for construction works which (as a
whole and in their separate parts) are fit for their intended use,
account being taken of economy, and in this connection satisfy the
following essential requirements where the works are subject to
regulations containing such requirements. Such requirements must,
subject to normal maintenance, be satisfied for an economically
reasonable working life (Table 1).
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*Table 1. ESSENTIAL REQUIREMENTS
ESSENTIAL REQUIREMENT 1995 - 20072007- presentAResistance and
stability Mechanical resistance andstability BSafety in use Safety
in case of fire CSafety in case of fire Hygiene, health and
theenvironment DHygiene and health of man(workers, occupants or
neighbours) andenvironment protection andrehabilitationSafety in
use EHeat retention, Waterproofinsulation and Energy
economyProtection against noise FProtection against noise Energy
economy and heatretention
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*A. Mechanical resistance and stability The construction works
must be designed and built in such a way that the loadings that are
liable to act on them during their constructions and use will not
lead to any of the following: (a) collapse of the whole or part of
the work; (b) major deformation to an inadmissible degree; (c)
damage to other parts of the construction works or to fittings or
installed equipment as a result of major deformation of the
load-bearing construction; (d) damage by an event to an extent
disproportionate to the original cause.
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*B. Safety in case of fire
The construction works must be designed and built in such a way
that in the event of an outbreak of fire: (a) the load-bearing
capacity of the construction can be assumed for a specific period
of time; (b) the generation and spread of fire and smoke within the
construction works are limited; (c) the spread of fire to
neighboring construction works is limited; (d) occupants can leave
the construction works or be rescued by other means; (e) the safety
of rescue teams is taken into consideration.
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*C. Hygiene, health and the environment
The construction works must be designed and built in such a way
that they will, throughout their life cycle, not be a threat to the
hygiene or health and safety of workers, occupants or neighbors,
nor have an exceedingly high impact, over their entire life cycle,
on the environment quality or on the climate during their
construction, use and demolition, in particular as a result of any
of the following: (a) the giving-off of toxic gas; (b) the
emissions of dangerous substances, volatile organic compounds,
greenhouse gases or dangerous particles into indoor or outdoor air;
(c) the emission of dangerous radiation; (d) the release of
dangerous substances into ground water, marine waters, surface
waters or soil; (e) the release of dangerous substances into
drinking water or substances which have an otherwise negative
impact on drinking water; (f) faulty discharge of waste water,
emission of flue gases or faulty disposal of solid or liquid waste;
(g) dampness in parts of the construction works or on surfaces
within the construction works.
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* D. Safety (and accessibility) in use The construction works
must be designed and built in such a way that they do not present
unacceptable risks of accidents or damage in service or in
operation such as slipping, falling, collision, burns,
electrocution, injury from explosion and burglaries.
In particular, construction works must be designed and built
taking into consideration accessibility and use for disabled
persons.
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* E. Protection against noise The construction works must be
designed and built in such a way that noise perceived by the
occupants or people nearby is kept to a level that will not
threaten their health and will allow them to sleep, rest and work
in satisfactory conditions.
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* F. Energy economy and heat retention
The construction works and their heating, cooling, lighting and
ventilation installations must be designed and built in such a way
that the amount of energy they require in use shall be low, when
account is taken of the occupants and of the climatic conditions of
the location.
Construction works must also be energy-efficient, using as
little energy as possible during their construction and
dismantling.
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*2.3. CONSTRUCTION INDUSTRY CHARACTERISTICS
Working place (site) is temporary, continously changing; Product
(built facility) is unique, immobile Processes are mobile;
Production process mainly outdoor; Production process continuously
changing. Variety of construction technology, and structure of
industry; Requires other industries to support it; Complex and
expensive;
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Lond lastind life-cycle; Many people/organizations involved in
promotion, construct and use; High incidence of risk and
uncertainty in demand pattern and technical conditions; The product
is usually commisioned and not bought; Complex and expensive;
Demand is fluctuant, depending largelly by government; Requires
large and various ammount of materials, equipment and workforce
(seldom highly qualified), etc.
*
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*2.4.Construction Quality System
Participants to Construction Industry - form a heterogeneous set
of persons and / or organizations among which are created, by law
and various ad hoc relationships, multiple and diverse connections
and conditions. The quality of construction is the result of this
heterogeneous set of factors, namely: :
Client;Consultant/Designer;Contractor;Suppliers;Other consultants
and service supliers: expert witnesses, design verifiers, technical
advisors, laboratories etc.;Local and central authorities;State
Inspectorate in Construction, etc.
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*All these direct and indirect participants create ad-hoc a
complex system, whose final result is the development of
anthropogenic environment.
Law 10/1995 defines the Construction Quality System as a set of
organizational structures, resposibilities, and instruments which
are involved in obtaining quality of the built asset throughout its
entire lyfe - cycle (promotion, design, construction, use and
demolition).
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* Construction Quality System (CQS)
a) Codes and regulations; b) Materials, Products, Components;c)
Technical approvals (agremente tehnice) for new products and
technologies;d) Design verification (quality control), Quality
control of the works and Expert witnesses of the designs, works and
built facilities;e) Quality management ;f) Laboratory approval and
testing;g) Construction metrology;h) Commissioning
(handing-over);i) In use construction behavior and interventions;j)
Demolition and disposal;k) State control of construction
quality.
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*Construction Quality System (CQS) may be seenas a Cybernetic
open systen
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*System = a set of interacting or interdependent components and
rules forming an integrated whole (ex: organizational structures,
laws, responsibilities, construction codes etc with various
conexions in between).Input = customer and community needs and
requirements; System behavior = it contains processes that
transform inputs into outputs (material, money, energy or data);
Output = design, built facility.
Cybernetic System = are capable of receiving, storing and
processing information so as to use it for self control, using
feed-back.
Open Cybernetic System = exchanges matter and energy with its
surroundings/environment (competitors, suppliers, local/central
authorities, banks, etc). Usually, environment induces
restrictions
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*Comments about system behavior Each person and/or organization
within the system has speciffic interests, which can be even
opposite. Inside organizations importance approach regarding
various objectives can outline a speciffic objective affecting
another (ex. Quantity/Profit more important than quality, Time
reduction more important than quality improvement, etc);Partizan
attitude within the departments affecting the company global
objectives.The more components of the system, the higher incidence
of failers occurs.