Curs nr 2

1. Curs nr 2

2. 5.Conceptul de sistem in constructii Printre diferitele definiţii propuse pentru notiuneagenerala de sistem, urmatoarea se pare a fi cea mai potrivita : • Un sistem reprezintă o colecţie de obiecte, interacţionând unul cu altul, care reacţionează într-un mod specific şi predictibil la oricare schimbare ce are loc în ambianţa lui. • Caracteristica fundamentala a conceptului desistem constă în validitatea principiului de unitate şi interdependenţăintrepărţi şi si a intregului; ceea ce inseamna ca o entitate complexă nu permite izolarea niciunui element component şi analizarea lui în absenţa altor componente. • O alta caracteristică importanta a teoriei de sistem este reprezentata de caracterul ei universal, atat prin limbaj cat si ca domeniu de activitate.

3. 5. The System Concept • Among different definitions proposed for the general notion of system, the following one seems the most appropriate: “A system represents a collection of objects, interacting to each other, which reacts in a specific and predictable way to any change occurring in its environment”. • A fundamental characteristic of the system concept consists in the validity of the principle of unity and interdependence of parts and of the whole; this means that a complex entity does not allow the isolation of any component part and its investigation in the absence of the other components. • Another important feature of the theory of systems is represented by its universal character , in terms of both language and instruments used.

4. Aplicareaconceptului de sistem in constructii • Complexitatea fizica a unei clădiri face obligatorie aplicarea conceptului de sistem considerandu-se clădirea ca un ansamblu de elemente interconectate unul cu celalalt şi cu mediul ambiant si care coopereaza pentru a indeplini diferite functiuni. • Aceastastructurarepecriteriifunctionale divide fiecare sistem in subsistemecevoravea o functiunepropriece trebuieindeplinitaindiferent de rezolvareaconstructiv tehnologicaconcreta. • Fiecaresubsistem al sistemuluicladireeste un sistem in raport cu proprialuistructura, sipoatefidescompusmai departe in subansambluri constructive • subansamblurile se pot descompune la randullor in elemente constructive sielementele incomponente

5. Applying the Concept to Buildings • The extreme physical complexity of a building makes compulsory, the application of system concept by considering the building as an ensemble of elements interconnected to each other and to the environment, which cooperate to fullfillcertain functions. • The first step consists in the construction of an adequate model of breaking up the building, corresponding to several hierarchic levels. • Such a model should achieve a functional break-up of the building systeminto severalsubsystems, each one being characterised by a global specific function. These subsystemscan be considered as a systemwith respect to its own internal structure and functionality, made up of a number of subensembles. Each subensemble - considered to be organised as a system too – is composed of elements, interconnected in such a way that they form a physical/functional entity. Many elements possess a physical/functional structure of enough complexity that can justify their breaking up into components.

6. SISTEMUL CLADIRE SUBSISTEME FUNCTIONALE SUBANSAMBLURI CONSTRUCTIVE ELEMENTE DE CONSTRUCTII COMPONENTE Daca se eliminasubsistemele de instalatiisiechipamente un astfel de model are cincisubsisteme: • spatiulinchis=volumulseparat de cladire din mediul natural inchissiprotejat in raport cu acesta • structura=portiunea din sistemulcladire care ii asigura acestuiarezistentasistabilitateamecanica

7. anvelopa=portiunea din sistemulcladire care ii asigura inchiderea in raport cu mediul natural • separatiileinterioare= portiunilesistemuluicladireneaflate in contact cu exteriorulsi care compartimenteazaspatiulinchis • separatiileexterioare = portiunileadiacenteanvelopeisiaflate in contact numai cu mediul exterior. • Exemple: structura tip cadru • acoperisurile • placile de planseu • scarile

8. BUILDING SYSTEM SUBENSEMBLES ELEMENTS COMPONENTS SUBSYSTEMS For current-type civil buildings, at a first hierarchic level of break-up, the building system includes the following subsystems: • indoor space units created by partitioning the whole building indoor space in accordance with functional requirements; • structure, i.e. that part of the building ensuring its mechanical strength and stability;

9. enclosure, i.e. that part of the building separating it from the outdoor natural environment; • interior partitions, i.e. those parts of the building (without contact with the outdoor environment) dividing its whole indoor space into indoor space units • exterior partitions, i.e. those parts of the building enclosure subsystem that is in continuous contact with the outdoor environment Here maybe also added the installation and equipments subsystems • EX: frame structure, floors or roofs structures

11. 6.Conceptul de performanta in constructii UtilizatorulConstructia ExigentePerformante

12. 6.The performance concept • Users Building • Exigencies Performances

13. Conceptul de abordare de performanta (performance approach) a fostintrodus in domeniul industrial inca din anii ‘50 de catrecercetatoriiamericani, pentru a ordonaconceptia siproiectarea, inovareatehnicasitehnologicasiprocedurile de control al calitatiiconceptiei, proiectariisiexecutiei • Mai tarziu, s-a introdussi in constructii“teoriaconceptului de performanta” ca fiind un instrument destinatsarationalizeze activitatile legate de “producerea” uneiconstructii, sastimuleze progresultehnic, orientandu-le spreasigurareaconditiilorsi criteriilor de satisfacere a cerintelorutilizatorilor. • Prima etapain aplicareateorieiconceptului de performanta in constructiiesteformulareaexigentelorutilizatorilor,ceeace nu se poate face decat in termenicalitativi, fara a se referi la o solutieconcreta.

14. From the viewpoint of its contents, working out and application, the performance concept in building construction represents a systematic procedure to establish the characteristics of buildings and of their component parts in order to get satisfactory response to all exigencies expressed by those involved in their utilisation. • All definitions proposed for the performance concept emphasise as a fundamental issue the fact that this kind of approach does not start from “what a product is and what it represents”, but from “what a product must provide, no matter what the concrete solution would be”. • This concept is defined as “an instrument aiming at rationalising both design and execution, stimulating promotion of technical progress and innovative solutions oriented towards ensuring conditions and specifying criteria able to satisfy as completely as possible users’ requirements”.

15. The starting point in a building performance analysis consists in the identification of its users’ exigencies (requirements). • Since the list of users’ exigencies must be set up for a specified functional type of building and not for a particular building, it becomes compulsory that this operation have a high degree of generalisation. • An exigency of building users’ represents the statement of one of their necessities related to the respective type of building. This statement is expressed in qualitative terms only, without reference to any particular solution.

16. The second step in a performance analysis consists in the conversion of users’ exigencies (requirements) into performance exigencies – presently called in Romanian documents, technical conditions of performance -, which are qualitative requirements associated with different physical and functional divisions of a building. The list thus worked out should be addressed to a potential solution, with no definite specification of means for its achievement. • The third step in a performance approach consists in establishing performance criteria, expressed quantitatively, to be used for assessing the degree of fulfilment for each performance exigency. More recently, an alternative term has been introduced for this notion (which is also presently used in Romanian documents), namely performance parameters.

17. The performance parametersare measurable characteristics associated with a building subsystem, which makes possible to quantify the degree of fulfilment for a certain performance exigency (technical condition of performance ) imposed to the respective subsystem. Performance parameters are intended to exert a control of achievement of the objective stated by the corresponding technical conditions of performance. Any performance parameter must have: • - its own notation; • - a specified unit of measurement; • - a physical significance, precise and non-equivocal; • - a computational model or an experimental procedure for assessing quantitative values.

18. The forth step consists in associating each performance parameter with a certain limit value (either maximum or minimum) or with a range of values, considered as compulsory. This is presently known as performance level and represents a reference value of the respective performance parameter, taken as a basis for evaluation its degree of fulfilment. The performance level associated to any performance parameter is specified by technical regulations. • Any solution provided by the design of a building must comply withthe levels of performance specified by appropriate technical regulations. The values corresponding to the design solutions are termed design performances.

19. Listareaexigentelor nu se poate face decatpetipuri functionale de cladire, si nu pefiecare tip de cladire in parte. • A douaetapape care o presupuneabordarea de performantaesteconvertireaexigentelor (cerintelor) utilizatorilor in exigentetehniceasociateunordiviziuni tehnicesifunctionale ale cladirii. Exigentetehnice=exigente de performanta =conditiitehnice de performanta=enuntulcalitatival uneiinsusiripe care trebuie sa o aiba un subsistem al uneicladiri • A treiaetapaestestabilireacriteriilor de apreciere a gradului de satisfacere a fiecareiexigente de performanta (criterii de performanta)=parametri de performanta=o caracteristica masurabila a unuisubsistem cu care se poatecuantificagradul de indeplinire a uneiconditiitehnice de performantaimpuse acestuia

20. Fiecareparametru de performanta are • O notatieproprie • O unitate de masura • O semnificatiefizicaprecisasiunivoca • Un model de evaluareprincalculsi/sau o metoda de determinarepecaleexperimentala Ultimaetapaa abordarii de performantaesteasociereafiecarui parametru de performantauneivalorilimita, minima sau maxima, numitanivel de performanta = valoarea de referinta a unuiparametru de performanta in raport cu care se evalueazaindeplinireaacestuia. Nivelul de performantaasociatunuiparametru de performantaesteprecizatsiimpusprinreglementariletehnice de specialitate.

22. DirectivaEuropeana 89/106 CEEsiLegea 10 referitoare la Calitatea in Constructii • În cadrul activităţilor desfasurate de Uniunea Europeana, a fost elaborat un sistem de documente cuprinzător şi bine organizat  privitor la activitatea in constructii. • Una dintre caracteristicile cele mai importante este maniera exigentiala în care sunt concepute fiind în esenţă diferit de unul tradiţional descriptiv. • Un document de bază în aceasta directie, Directiva Europeana 89/106 EEC, a fost prezentata statelor membre UE în decembrie 1988 şi a fost pusa în aplicare exact trei ani mai tarziu. Premisele principale pentru publicare acest document aufost:

23. 7.The Construction Products Directive (89/106/EEC) • Within the framework of European Union activities, a comprehensive and well-organised system of documents concerning constructions has been developed over the last two decades. One of the most important features of these documents lies in the fact that they are conceived and written in an exigential manner, thus being essentially different from the traditional descriptive ones. • A basic document in this respect, the Construction Products Directive (89/106/EEC) was notified to the EU member states in December 1988 and implemented exactly three years later. The main premises for issuing this document were:

24. all member countries wish to ensure that on their territories construction works are achieved so that, alongside with safety of humans, domestic animals and property, all other exigencies of general interest will be secured; • in all member countries, alongside with regulations related to safety exigencies of buildings, there are also provisions concerning users’ health, economy of energy, environmental protection, durability, economical aspects of building construction and exploitation etc; • all member countries do have national regulations for all kinds of exigencies, thus enabling the issuance of corresponding European harmonised regulations.

25. The Directive describes a “construction product” as any product that is created for incorporation in a permanent manner in construction works.Tofall within the scope of the Directive, a product must meet four criteria: it must be produced; placed upon the market; incorporated in a permanent manner in the works; relate to at least one of the Essential Requirements. • The Construction Products Directive requires that construction products are fit for the purpose for which they are intended and that they may satisfy national regulations. A number of six Essential Requirements are set out in the Directive; at least one of them must apply to the product in use. The list of Essential Requirements associated to buildings includes: 1. Mechanical resistance and stability 2. Safety in case of fire 3. Hygiene, health and environment 4. Safety in use 5. Protection against noise 6. Energy economy and heat retention.

26. All these requirements are stated in the form of “objectives”, as exemplified below for some of them: • Mechanical resistance and stability. A construction must be conceived, designed and achieved so that, under the actions likely to occur during its service (life) period, none of the following events occurs: - total or partial failure (collapse); - excessive deformations and deflections; - damage of certain parts of the construction works, fitting or equipment, due to significant deformations of structural elements; - damage resulting from accidental events, excessively large with respect to the magnitude of the event. Safety in case of fire. A construction must be conceived, designed and achieved so that, if fire breaks out: • stability of structural elements, as well as their capacity to support loads, be maintained for a specified period of time;

27. spread of fire and smoke within the construction or to neighbouring works be limited; - occupants be allowed to escape or to be rescued; • emergency squads can operate quickly, efficiently and without excessive risks It is specified that, under the condition of normal maintenance, all essential requirements associated to a building must be satisfied over its entire life period “economically reasonable”. This last specification is translated as “that period of time during which building performances can be maintained at a level consistent with the fulfillment of essential requirements”, depending on: - costs associated to the situation when the building becomes unusable; - risks and consequences of construction failure, togheter with costs related to insurance against them; - estimated partial refurbishment works; - maintenance cost; - demolition cost; - environmental (ecological ) costs resulting from either maintaining the building in use or demolishing it.

28. The Romanian regulations presently in force that govern the application of performance concept to buildings are generated by the Law of Quality in Constructions (Law No. 10/1995). The “Essential Requirements” specified by this law and by all connected regulations are consistent with those included in the Construction Products Directive and its associated Interpretative Documents issued by the European Economic Community (see 2.3.2.). They appears as: • A. Resistance and stability; • B. Safety in use; • C. Safety against fire; • D. Hygiene people’s, health, restoration and protection of environment; • E. Thermal insulation, waterproofing and economy of energy; • F. Protection against noise.

29. toate ţările membre au dorit să aiba garantia ca pe teritoriul lor lucrarile de constructii sunt realizate astfel incat pe langa securitatea persoanelor, animalelor si bunurilor toate exigentele de interes general vor fi respectate. • în toate ţările membre, alături de dispoziţii în legătură cu exigentele de siguranţă ale clădirilor, există de asemenea prevederi privitor la sănătatea utilizatorilor, economia de energie, protecţia împotriva influenţelor exterioare ,durabilitate, aspecte economice de construcţie şi exploatare etc; • toate ţările membre au dispoziţii naţionale pentru toate tipurile de exigente, astfel putandu-se redacta reglementari armonizate la nivelul fiecarei tari

30. Directiva stipuleaza ca un produs „constructie" trebuie sa fie potrivit pentru scopul in care a fost creat si sa satisfaca cererile impuse de reglementarile nationale; • Exista 6 Exigente Esentiale asociate unei cladiri, care acopera reglementarile nationale si care trebuie sa fie indeplinite simultan: • 1.Rezistenţă mecanică şi stabilitatea • 2. Siguranţă în caz de incendiu • 3. Igienă, sănătate şi mediu inconjurator • 4. Siguranţă în utilizare • 5. Protecţie împotriva zgomotului • 6. Economia de energie şi izolarea termica

31. Legea 10/1995, lege in vigoare la ora actuala cu un numar de imbunatatiri si actualizari, instituie SISTEMUL CALITATII IN CONSTRUCTII,acesta fiind definit ca : „ansamblul de structuri organizatorice, responsabilitati, regulamente proceduri si mijloace care concura la realizarea calitatii constructiilor in etapele de concepere, realizare, exploatare si postutilizare a acestora” • Pentru obtinerea unor constructii de calitate legea 10 , modificata si adaugita instituie obligativitatea realizarii si mentinerii pe toata durata de existenta a constructiei a 6 cerinte esentiale, consecvente cu acele incluse în Directiva Comunitatii Europene. Ele sunt: • A. Rezistenţă şi stabilitatea; • B. Securitate la incendiu; • C. Igiena, sanatate si mediu, • D. Siguranta in exploatare • E. Protectie impotriva zgomotului • F. Economie de energie si izolarea termica