Smits A.,Belgian Building Research Institute BBRI |
Nicaise D.,Belgian Building Research Institute BBRI |
de Barquin F.,Belgian Building Research Institute BBRI |
Hariri K.,University of Stuttgart |
Bosnjak J.,University of Stuttgart
Brick and Block Masonry: Trends, Innovations and Challenges - Proceedings of the 16th International Brick and Block Masonry Conference, IBMAC 2016 | Year: 2016
New lightweight granular materials, called ‘3I’ loose-fill materials (Inorganic, Insulating and Incombustible), were developed in the LEEMA-EU project. They are based on inorganic polymers derived from mineral tailings, recycled glass and industrial by-products and are produced as lightweight hollow aggregates. They have superior thermal conductivity, reduced embodied energy and lower cost compared to currently applied bulk insulation products. They can be used for the insulation of cavity walls or between rafters to meet energy regulations. They are also used as lightweight aggregates in boards or blocks and filling of masonry block perforations. In this paper the focus is on their application as grains in cavity walls using a blowing machine. Two types of walls were studied: existing double-leaf masonry walls and new lightweight timber-frame walls. The thickness of the air space and the size of the holes for blowing the grains differ considerably for both applications. The aim of the test program was to study the feasibility of using existing blowing machines. A commercially available granular material was tested for comparison. First of all, the characteristics of both materials were determined and will be presented. Secondly, test setups were developed for blowing simulation. Finally, since dust release is a big issue, different analyses were performed to compare the release during blowing. Recommendations on the settings of the blowing equipment are made. For timber-frame structures, the tests show feasibility when sufficient tube diameter is used to simulate pouring instead of blowing under pressure to avoid grain destruction. For double-leaf walls the tests are not successful due to powder formation. Other techniques need to be studied simulating more closely pouring (only possible for new-built walls). Conclusions on the dust release are that considerable lower quantities of fine dust are released for 3I loose-fill grains compared to the reference material. © 2016 Taylor & Francis Group, London.
Allani M.,Belgian Building Research Institute BBRI |
Van Lysebetten G.,Belgian Building Research Institute BBRI |
Huybrechts N.,Belgian Building Research Institute BBRI |
Huybrechts N.,Catholic University of Leuven
Springer Series in Geomechanics and Geoengineering | Year: 2017
The use of energy piles remains a topic of discussion in Belgian practice. The main concern is the lack of knowledge and documented experience with regard to the energy performance. Another issue is the potential impact of temperature changes and temperature cycles on the pile response (bearing capacity, settlements), in particular for piles with a relative small diameter. To address this challenge, an extensive full-scale test campaign on several types of energy piles has been set up. The energy piles are instrumented over their entire length with Fibre Bragg Grating (FBG) optical sensors and thermocouples. The tests aim at thermally characterizing the piles, as well as determining the combined thermo-mechanical behaviour. This paper presents an overview of the first, preliminary results of the test campaign and assesses the potential of a fully coupled analysis with the Finite Element Method (FEM) in Plaxis 2D software, showing a good agreement with the measurements. © Springer International Publishing AG 2017.
Delvaeye R.,Catholic University of Leuven |
Delvaeye R.,Belgian Building Research Institute BBRI |
Ryckaert W.,Catholic University of Leuven |
Stroobant L.,Catholic University of Leuven |
And 4 more authors.
Energy and Buildings | Year: 2016
Daylight control systems, which automatically adjust the artificial light levels depending on the daylight penetration, can result in substantial energy savings. However, their energy saving potential cannot be estimated accurately because it depends on several building and system parameters, climate conditions, occupant behaviour and type and commissioning of the daylight control system. The objective of this paper is to compare the energy saving potential and operation of different daylight control systems in school buildings. One year monitoring has been carried out simultaneously in 3 neighbouring classrooms, equipped with a different type of control system. The active power and the electric energy consumption of the artificial lighting were measured continuously on a minute-by-minute basis, as well as the occupancy of the classrooms and the global irradiance outside the building under an unobstructed horizon. Momentary visual comfort assessments were carried out in the classrooms. Although all classrooms have comparable occupancy and identical building characteristics, differences between the annual energy savings of the different daylight control systems are found to be significant: the total annual energy savings varied from 18% to 46%. Under the given conditions, the open loop system with the outward facing daylight sensor was noticed to yield the largest while the closed loop system with centrally positioned sensor produced the smallest savings. However, it has to be made sure that the energy savings are not at the expense of the visual comfort. The performance of the systems regarding both energy savings and visual comfort is related to the operation and the initial commissioning. An in-depth analysis of the monitoring campaign is discussed to explain the differences in energy savings and visual comfort. The energy savings due to the implementation of a daylight control system are divided into on the one hand dimming due to daylight penetration and on the other hand initial dimming to compensate for the over dimensioning of the lighting system and to take into account constant illuminance control. © 2016 Elsevier B.V.
Boehme L.,Catholic University College of Bruges-Ostend |
Boehme L.,Catholic University of Leuven |
Vrijders J.,Belgian Building Research Institute BBRI |
Van Gysel A.,Catholic University of Leuven |
Van Gysel A.,Lessius University College Antwerp
fib Symposium 2012: Concrete Structures for Sustainable Community - Proceedings | Year: 2012
This paper presents some relevant aspects in using recycled concrete aggregates (RCA) in structural concrete: variability of the properties of RCA, mix design and durability of concrete with RCA. The aim of this research is to investigate the potential use of RCA in structural concrete C20/25 & C25/30 in the exposure classes X0, XC1, XC2, XC3, XF1, by replacing 100 % of the coarse aggregates by RCA. The properties of RCA provided by the recycling industry are investigated, as well as the properties of fresh and hardened recycled concrete. Finally, durability tests regarding to the exposure classes, are performed.
Deltour J.,Universitecatholique Of Leuven Ucl |
D'herdt P.,Belgian Building Research Institute BBRI |
Deneyer A.,Belgian Building Research Institute BBRI |
Bodart M.,Universitecatholique Of Leuven Ucl
Light and Engineering | Year: 2011
The use of energy efficient lighting in dwellings in combination with the preservation, or the improvement of visual comfort is a huge challenge. This paper presents a lighting renovation project in eight social apartments, in Belgium. The lighting system was renovated at four levels of quality, in order to evaluate the light saving potential, the lighting comfort and the influence of the human behaviour on the lighting consumption. The methodology dealt with the criteria and targets of the lighting renovation, the way to record monitoring data and the concept of the extrapolation of consumption. This extrapolation presented a way to obtain more case studies without knowing the occupancy schedule of the occupants. Illuminance, power, luminance, UGR values reached for the different lighting solutions were determined. The measurements showed that if the occupant selected his lighting installation, the comfort is seldom reached. Replacing initial lamps (incandescent) by high efficient compact fl uorescent lamps induced high energy savings and comfort level was reached more often. The visual comfort (higher illuminance level) could even be improved by the use of efficient luminaires. Finally, the paper concludes that, the human behaviour has a large influence on the lighting installation and consumption. Moreover, occupants tended to install the worst lighting equipment (high power level, low visual comfort). However efficient luminaries are not widespread on the domestic lighting market. On the other hand, the extrapolation allowed concluding that for some behaviour profiles there were no economic gains from the use of economic lamps and efficientluminaires. With this study, we point to the importance of evaluating correctly the needs of the occupants in terms of visual comfort and to install adequate energy saving lamps and luminaires.
Holeyman A.,Catholic University of Louvain |
Bertin R.,Catholic University of Louvain |
Whenham V.,Belgian Building Research Institute BBRI
Soil Dynamics and Earthquake Engineering | Year: 2013
This paper describes analytical solutions for assessing the axial dynamic response of the shaft of a pile subjected to vibratory loads, with particular reference to pile vibratory driving. Radial inhomogeneity arising from shear modulus degradation is accounted for by assuming continuous variations of the medium properties. This approach alleviates wave reflections from the interface between inner (nonlinear) and outer (linear) zones. Novel analytical solutions are presented for two cases describing the radial decrease of the soil modulus according to (a) a linear law and (b) a parabolic law. The results are evaluated over a wide range of parameters and compared with those obtained by a semi-analytical model derived from Michaelides et al. [14,15] and by a radial discrete model simulating the pile and soil movements from integration of the laws of motion (Hipervib-II model) (Holeyman ). © 2012 Elsevier Ltd.
Denies N.,Belgian Building Research Institute BBRI |
Huybrechts N.,Belgian Building Research Institute BBRI |
De Cock F.,Geotechnical Expert Office Geo.be |
Lameire B.,Belgian Association of Foundation Contractors |
And 3 more authors.
Geotechnical Engineering for Infrastructure and Development - Proceedings of the XVI European Conference on Soil Mechanics and Geotechnical Engineering, ECSMGE 2015 | Year: 2015
The deep mixing method, first used several decades ago, is nowadays a worldwide accepted ground improvement technology. In recent years, this process has undergone a rapid development, particularly with regard to its range of applications, its cost effectiveness and environmental advantages. The deep mixing method has increasingly been used for applications such as earth and water retaining walls or as alternative to traditional foundation solutions. Although the mechanical characterization of the deep soil mix material has evolved a lot, the question of its durability remains an important issue. There are not only the questions related to the degradation of the soil mix material with time, mainly due to wet-dry and freeze-thaw cycles, and potential carbonation effects, but there are also the uncertainties over the durability of the soil mix material executed in contaminated soils. The present paper attempts to identify the governing parameters and the factors influencing the long-term behaviour of the soil mix material. Consequences of this study for the design requirements and rules are discussed and this for the soil mix material itself, but also for the steel reinforcement installed into the fresh material during execution. Recent knowledge gained from the soil mix remediation of brownfield areas is also highlighted with the aim to collect a maximum of information regarding the effects of contaminants on the durability of the soil mix material. © The authors and ICE Publishing: All rights reserved, 2015.
Pierard J.,Belgian Building Research Institute BBRI |
Pollet V.,Belgian Building Research Institute BBRI |
Cailleux E.,Belgian Building Research Institute BBRI |
Pierre C.,Belgian Research Center for the Cement Industry
fib Symposium 2012: Concrete Structures for Sustainable Community - Proceedings | Year: 2012
The lower hydration rate of cements containing high Ground Granulated Blast-Furnace Slag (GGBFS) contents generally makes the concrete more sensitive to drying, with the result that a weak surface layer may be formed. A previous study indicated that some chemical admixtures and mineral additions are effective to accelerate the setting and hardening of mortars made with cements containing 70% to 85% of GGBFS. In this paper, the influence of these products on the early-age strength and some durability properties of high slag cement based concrete is investigated. The results show in particular that the use of a calcium nitrate based accelerator increases the 2-day compressive strength by up to 75% and helps to enhance the concrete carbonation resistance.
Crispin C.,Belgian Building Research Institute BBRI |
Mertens C.,Belgian Building Research Institute BBRI |
Medved J.,Slovak University of Technology in Bratislava
Building Acoustics | Year: 2014
The dynamic stiffness of a resilient material used under a floating floor is often used to predict the improvement of the impact sound pressure level, ΔL. It is also used to compare products. The measurement accuracy of this parameter is therefore essential. Unfortunately, the comparison between the predicted and the measured ΔL results shows quite high deviations which could be attributed, in part, to an incorrect estimation of the dynamic stiffness. It is now accepted by all European laboratories that the measurement procedure described in the standard ISO 9052-1 should be reviewed. This paper proposes a first step in the improvement of the measurement setup by taking into account the actual contribution of the dynamic stiffness of the air enclosed in the materials on the total dynamic stiffness. A new setup is proposed and some results are presented for products with different airflow resistivities.
Whenham V.,Belgian Building Research Institute BBRI |
Holeyman A.,Catholic University of Louvain
Geotechnical and Geological Engineering | Year: 2012
The vibratory driving technique consists in applying a vibratory load onto a profile to reduce the ground resistance and allow penetration of the profile under its own weight. The vibratory action is produced by counter-rotating eccentric masses actuated within the exciter block. A proper definition of this mechanical action is fundamental for vibratory driving analyses. The vibratory force transferred from the vibrator onto the pile during vibratory driving is however generally neither well defined nor understood, in particular when using simplified closed form solutions for the analysis of pile driving. Few authors have pointed out the very low ratio observed between the force measured in the pile and the nominal inertial force developed by the eccentrics, but without offering a theoretical framework to explain and predict this low ratio. The objective of this paper is to develop a better understanding of the so-called 'efficiency factor' of the vibratory driving process. Analytical solutions are presented, along with more advanced numerical simulations. Theoretical solutions are illustrated with reference to field measurements collected at different test sites. © 2012 Springer Science+Business Media B.V.