International Journal of Engineering Science, 1978
constitutive equations for saturated sands are proposed. They exhibit the interaction of dilatati... more constitutive equations for saturated sands are proposed. They exhibit the interaction of dilatation and shear stress observed in sands in its small strain range. The equations are based on a continuum theory derived from a Newtonian approach to a mixture of a nonlinear solid and compressible fluid. The determination of the constitutive parameters from common soil mechanics experiments is discussed and illustrated by qualitatively valid numerical results.
This publication compiles the heat, air and moisture transfer terminology existing in books, stan... more This publication compiles the heat, air and moisture transfer terminology existing in books, standards and other reference documents. A small introduction is provided in Chapter 1 to present the CIB Commission W040 – Heat and Moisture Transfer in Buildings and to summarise the Commission activities since its formation in 1969. Chapter 2 indicates the guidelines for the use of this document. In Chapter 3 both parameters and concepts are presented, their definition according to the literature and the symbol(s) and unit(s) that are commonly used to describe it. Finally, Chapter 4 lists all the reference documents that were taken into consideration to develop this document.
ABSTRACT: This article demonstrates how monitoring of construction during a laboratory mock-up te... more ABSTRACT: This article demonstrates how monitoring of construction during a laboratory mock-up test was used to diagnose proneness to air leakage and to devise improved details. The curtain wall was built on a moveable, rigid frame that simulates the load-bearing structure. Construction details and components were identical to those used in actual buildings. The frame brings the curtain wall into contact with the test box, ensuring that the wall’s structural supports are not affected. Construction activities were monitored while the measurements included air flow rate versus air pressure difference across the wall, and horizontal deflections of wall mullions and beams. Locations of leakage points were detected using white smoke. The wall showed a density of air flow rate of 1.5m3m2h1 at a pressure difference of 300 Pa, barely meeting the requirements for EN 12152 classification level A2. Correlating leakage points with detected construction weaknesses led to remedial actions by the ...
A CAD assistant, PREVENT, has been developed to help evaluate building performance during the var... more A CAD assistant, PREVENT, has been developed to help evaluate building performance during the various design stages. The system accommodates the whole design process and provides both evaluation and diagnosis upon request. It has the capability to capture the design intent directly from sketches and to evaluate the fitness of the emerging solution to the demands of the building user. The structure and the functions of various components of evaluation by PREVENT are presented. A design model for a performance evaluation by PREVENT is proposed and tested.
Dwellings in Israel must include a residential protected room made of thick concrete slabs and wa... more Dwellings in Israel must include a residential protected room made of thick concrete slabs and walls, with an extremely airtight window and outward opening extremely airtight steel door. An inward opening regular door is applied for everyday usage. Being multipurpose, the residential protected room raised concern regarding long-term radon exposure. This article presents the stage of air change rate investigation (using SF6 as tracer gas) and radon monitoring in a multidisciplinary research performed by two teams. It comprised six residential protected rooms in a tall unoccupied building, including various scenarios of window and door closure. The teams established a common theoretical model and addressed sensitivity to differences in assumptions and methods of analysis. Similar orders of magnitude of air change rates and free surface exhalation rates were obtained, but with nonnegligible discrepancies between specific values. Tracer gas method results were more sensitive to calculat...
Energy conscious design of school buildings, as well as deemed-to-satisfy provisions in a Perform... more Energy conscious design of school buildings, as well as deemed-to-satisfy provisions in a Performance Based Energy Code, should address the problem known as the energy efficiency-thermal comfort-indoor air quality dilemma (EE-TC-IAQ Dilemma). In warm and moderate climates, the large internal heat sources usually found in school buildings prevent achieving thermal comfort without active cooling in summer, but are not sufficient to eliminate the need for heating in winter. Commonly used air-conditioners do not improve air quality, while natural ventilation induces uncontrolled energy losses. In this study, a step by step process was used for the development of deemed-to-satisfy design solutions, which cope with the EE-TC-IAQ Dilemma, for a performance based code. A distinction is made between improving building design variables and improving ventilation schemes. Results indicate that implementation of improved ventilation schemes in an otherwise well designed energy-conscious building result in savings of 28-30% and 17-18% for northern and southern classroom orientations, respectively.
The main research objective was establishing a simple but reliable methodology for the building d... more The main research objective was establishing a simple but reliable methodology for the building design stage that would yield environmentally optimal buildings. A three-step methodology is proposed: (1) design variable grouping-four distinct groups were recognized according to their stage of major influence (production and construction, operational energy, maintenance to demolition, and an Integrated Group relevant to several life cycle stages), (2) generating the within group optimization methodology, and integration.
The paper formulates some fundamental principles of performance-based design (PBD), suggesting a ... more The paper formulates some fundamental principles of performance-based design (PBD), suggesting a conceptual framework and systematic approach suitable for application in most areas of building design, and in the development of simulation tools and performance test methods required in the design and assessment processes. A schematic algorithm, which has been developed for the common engineering approach, was helpful in identifying the inter-relation with the required knowledge-based databases and tools that are needed for proper implementation of PBD. It is also shown that this schematic algorithm can serve not only as a conceptual model but also as the basic framework for developing or adapting simulation tools that are intended for PBD and assessment. The last part of the paper demonstrates the application of the fundamental approach in several areas of building performance (fire safety, acoustics, moisture safety, indoor air quality, and durability), outlining in each area the main user needs, ensuing performance requirements, and the most significant capabilities required of adequate simulation tools, with an emphasis on input/output.
The paper analyses the main features of a Performance Test Method (PTM), and demonstrates that, d... more The paper analyses the main features of a Performance Test Method (PTM), and demonstrates that, despite the wide range of attributes for which PTMs are required, the Performance Concept sets a unified common approach for their development. The basic relations between the four factors: a human requirement, the relevant behavioral aspects of the building and its parts, the evolving performance criteria, and the associated PTMs for evaluating compliance, establish the integrated approach presented here. It is demonstrated that PTMs should yield Response Curves as a basic tool for evaluations, assessments and decisions, while prevalent test methods, which are assigned to yield only Pass/Fail results, may be misleading. A procedure for relating compliance to the form of the Response Curve is suggested, with a differentiation between “brittle”, concave and convex curves.
International Journal of Engineering Science, 1978
constitutive equations for saturated sands are proposed. They exhibit the interaction of dilatati... more constitutive equations for saturated sands are proposed. They exhibit the interaction of dilatation and shear stress observed in sands in its small strain range. The equations are based on a continuum theory derived from a Newtonian approach to a mixture of a nonlinear solid and compressible fluid. The determination of the constitutive parameters from common soil mechanics experiments is discussed and illustrated by qualitatively valid numerical results.
This publication compiles the heat, air and moisture transfer terminology existing in books, stan... more This publication compiles the heat, air and moisture transfer terminology existing in books, standards and other reference documents. A small introduction is provided in Chapter 1 to present the CIB Commission W040 – Heat and Moisture Transfer in Buildings and to summarise the Commission activities since its formation in 1969. Chapter 2 indicates the guidelines for the use of this document. In Chapter 3 both parameters and concepts are presented, their definition according to the literature and the symbol(s) and unit(s) that are commonly used to describe it. Finally, Chapter 4 lists all the reference documents that were taken into consideration to develop this document.
ABSTRACT: This article demonstrates how monitoring of construction during a laboratory mock-up te... more ABSTRACT: This article demonstrates how monitoring of construction during a laboratory mock-up test was used to diagnose proneness to air leakage and to devise improved details. The curtain wall was built on a moveable, rigid frame that simulates the load-bearing structure. Construction details and components were identical to those used in actual buildings. The frame brings the curtain wall into contact with the test box, ensuring that the wall’s structural supports are not affected. Construction activities were monitored while the measurements included air flow rate versus air pressure difference across the wall, and horizontal deflections of wall mullions and beams. Locations of leakage points were detected using white smoke. The wall showed a density of air flow rate of 1.5m3m2h1 at a pressure difference of 300 Pa, barely meeting the requirements for EN 12152 classification level A2. Correlating leakage points with detected construction weaknesses led to remedial actions by the ...
A CAD assistant, PREVENT, has been developed to help evaluate building performance during the var... more A CAD assistant, PREVENT, has been developed to help evaluate building performance during the various design stages. The system accommodates the whole design process and provides both evaluation and diagnosis upon request. It has the capability to capture the design intent directly from sketches and to evaluate the fitness of the emerging solution to the demands of the building user. The structure and the functions of various components of evaluation by PREVENT are presented. A design model for a performance evaluation by PREVENT is proposed and tested.
Dwellings in Israel must include a residential protected room made of thick concrete slabs and wa... more Dwellings in Israel must include a residential protected room made of thick concrete slabs and walls, with an extremely airtight window and outward opening extremely airtight steel door. An inward opening regular door is applied for everyday usage. Being multipurpose, the residential protected room raised concern regarding long-term radon exposure. This article presents the stage of air change rate investigation (using SF6 as tracer gas) and radon monitoring in a multidisciplinary research performed by two teams. It comprised six residential protected rooms in a tall unoccupied building, including various scenarios of window and door closure. The teams established a common theoretical model and addressed sensitivity to differences in assumptions and methods of analysis. Similar orders of magnitude of air change rates and free surface exhalation rates were obtained, but with nonnegligible discrepancies between specific values. Tracer gas method results were more sensitive to calculat...
Energy conscious design of school buildings, as well as deemed-to-satisfy provisions in a Perform... more Energy conscious design of school buildings, as well as deemed-to-satisfy provisions in a Performance Based Energy Code, should address the problem known as the energy efficiency-thermal comfort-indoor air quality dilemma (EE-TC-IAQ Dilemma). In warm and moderate climates, the large internal heat sources usually found in school buildings prevent achieving thermal comfort without active cooling in summer, but are not sufficient to eliminate the need for heating in winter. Commonly used air-conditioners do not improve air quality, while natural ventilation induces uncontrolled energy losses. In this study, a step by step process was used for the development of deemed-to-satisfy design solutions, which cope with the EE-TC-IAQ Dilemma, for a performance based code. A distinction is made between improving building design variables and improving ventilation schemes. Results indicate that implementation of improved ventilation schemes in an otherwise well designed energy-conscious building result in savings of 28-30% and 17-18% for northern and southern classroom orientations, respectively.
The main research objective was establishing a simple but reliable methodology for the building d... more The main research objective was establishing a simple but reliable methodology for the building design stage that would yield environmentally optimal buildings. A three-step methodology is proposed: (1) design variable grouping-four distinct groups were recognized according to their stage of major influence (production and construction, operational energy, maintenance to demolition, and an Integrated Group relevant to several life cycle stages), (2) generating the within group optimization methodology, and integration.
The paper formulates some fundamental principles of performance-based design (PBD), suggesting a ... more The paper formulates some fundamental principles of performance-based design (PBD), suggesting a conceptual framework and systematic approach suitable for application in most areas of building design, and in the development of simulation tools and performance test methods required in the design and assessment processes. A schematic algorithm, which has been developed for the common engineering approach, was helpful in identifying the inter-relation with the required knowledge-based databases and tools that are needed for proper implementation of PBD. It is also shown that this schematic algorithm can serve not only as a conceptual model but also as the basic framework for developing or adapting simulation tools that are intended for PBD and assessment. The last part of the paper demonstrates the application of the fundamental approach in several areas of building performance (fire safety, acoustics, moisture safety, indoor air quality, and durability), outlining in each area the main user needs, ensuing performance requirements, and the most significant capabilities required of adequate simulation tools, with an emphasis on input/output.
The paper analyses the main features of a Performance Test Method (PTM), and demonstrates that, d... more The paper analyses the main features of a Performance Test Method (PTM), and demonstrates that, despite the wide range of attributes for which PTMs are required, the Performance Concept sets a unified common approach for their development. The basic relations between the four factors: a human requirement, the relevant behavioral aspects of the building and its parts, the evolving performance criteria, and the associated PTMs for evaluating compliance, establish the integrated approach presented here. It is demonstrated that PTMs should yield Response Curves as a basic tool for evaluations, assessments and decisions, while prevalent test methods, which are assigned to yield only Pass/Fail results, may be misleading. A procedure for relating compliance to the form of the Response Curve is suggested, with a differentiation between “brittle”, concave and convex curves.
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