Conference Agenda

Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).

Session Overview
Poster introductions 04: Innovative building materials
Wednesday, 25/Aug/2021:
11:15am - 11:40am

Session Chair: Prof. Umberto Berardi, Ryerson University
Location: Room 4 - Room 015, Building: 116

Show help for 'Increase or decrease the abstract text size'
11:15am - 11:18am

Influence of production on hemp concrete hygrothermal properties: sorption, water vapor permeability and water absorption

Aime Ruus1, Tarmo Koosapoeg1, Markus Pau2, Targo Kalamees3, Mattias Põldaru3

1Tartu College, School of Engineering, Tallinn University of Technology, Estonia; 2Viljandi Culture Academy, University of Tartu, Estonia; 3Department of Civil Engineering and Architecture, School of Engineering,Tallinn University of Technology, Estonia

Hemp concrete is considered to be carbon negative material. Hemp absorbs CO2 during the growth and lime needs CO2 for carbonation. Material - having good thermal insulation properties - is used as non-bearing wall material or plaster. For such use hygrothermal properties of material must be well known especially when indoor insulation is in focus. In current study hemp concrete produced in two different ways was in focus and following hygrothermal properties of building material were studied: water absorption (EN 1015‑18), water vapour sorption (EN 12571), water vapour permeability (EN 12572). Results can be used for hygrothermal calculations and modelling.

11:18am - 11:21am

The hygrothermal assessment of cement-ash-based mortar

Barbora Krejcirikova1, Carsten Rode1, Pawel Wargocki1, Jakub Kolarik1, Ruut Peuhkuri2

1Technical University of Denmark, Denmark; 2Aalborg University, Denmark

Cement is the second most consumed substance by weight in the world, after water. The growing demand for reduced emissions of CO2 urges the cement industry to find materials with low CO2 footprint, which calls for cement substitution. An assumption of the study has been that sewage sludge ash (SSA), an industrial by-product, can be applied as a potential cement substitute in cement-based materials without compromising the material performance. The study investigated the effect of partial replacement of cement by SSA in mortar on hygrothermal properties of mortar and its impact on indoor air quality. Two sewage sludge ashes originated from waste water treatment plants located in the Greater Copenhagen area, Denmark. The results on characterization of SSAs confirmed previous findings concluding that chemical composition of SSAs is highly variable. Granulometric examination showed that the SSAs typically consisted of larger particles compared to cement particles, thus cement-ash-based mortar resulted in more porous structures compared to cement-based mortar. The higher porosity was responsible for a decrease of thermal conductivity and an increase of vapour permeability of mortar. Sorption was tested by two methods: the climatic chamber method and the desiccator method and the observations proved that the sorption isotherms were influenced by the method applied.

11:21am - 11:24am

Assessment of moisture and mould of hempcrete and straw panels

Jane Raamets1, Laura Lokko1, Aime Ruus1, Targo Kalamees2, Karin Muoni1

1Tallinn University of Technology, School of Engineering, Tartu College, Estonia; 2Tallinn University of Technology, School of Engineering, Department of Civil Engineering and Architecture, Estonia

At present buildings contribute a third of total greenhouse gas emissions. There is a need for sustainable solutions and natural materials, which offer low-embodied energy and their low impact has a promising potential as construction alternatives.
Hempcrete is a lightweight insulation material, which is ideal for most climates. Hempcrete provides natural, airtight, and vapor-permeable insulation. Straw panels are also natural construction materials and they consist of extruded wheat straw and are surrounded on all sides by recycled paper. They ensure an excellent and healthy microclimate for a building via temperature and air humidity regulation.
There are some risks, which can be associated with the use of such materials - Infestation, biological degradation, presence of moisture and structural degradation.

The aim of the study is to determine the critical moisture level and mould resistance of hempcrete and straw panels.

The results of this study are valuable to scientists and structural engineers as well.

11:24am - 11:27am

Thermo-optical reaction changes of PCM filled glass systems

Terézia Cabanová1, Michal Kuruc1, Jakub Čurpek1,2, Daniel Urbán1, Miroslav Čekon1,2

1Slovak University of Technology, Slovak Republic; 2Brno University of Technology, Czech Republic

Research in the field of energy efficient building envelope technologies is currently being conducted regarding the integration of various types of responsive materials. In adaptive façade principles, transparent/translucent elements serve as a functional and also aesthetic part of the building envelopes. The main purposes of their use are to provide adequate level of daylight provision together with thermal stability in the internal environment of buildings along the time. The aim of the paper is to analyze thermo-optical reactions of the PCM-based glass elements which have the capability to store thermal energy together with a variable transparency level through the energy storage process (phase change) regarding a given temperature differences and intensity of incident solar radiation. Their various optical properties are determined by the level of phase transition at given boundary conditions over time. Special uncommon thermo-optical changes occur during its internal phase transition processes, from liquid to solid phase and vice versa (latent heat of fusion) within a given narrow range of temperature interval. PCM acts as random and diffusive media with relevant scattering effects in solid phase, however in liquid state are highly transparent with direct transmission and no relevant scattering effect. These internal physical changes were detailly identified by experimental test procedures based on optical properties measurements performed using a spectrophotometry, and parallelly with the stabilization of each temperature set provided by environmental chamber. As result of that, relevant differences in the PCM spectral feature can be identified for its different states (solid/liquid) in which transmittance spectra are unstable during rapid phase change process. This provides a substantial base line for the optimization of a PCM glazing system in terms of various degree of freedom for different building types and climate zones.

11:27am - 11:30am

Development of High Performance Aerogel Concrete (HPAC) and statistical evaluation of compressive strength for practical use in construction

Silvia Fickler, Torsten Welsch, Martina Schnellenbach-Held

Institute for Structural Concrete, University Duisburg-Essen, Germany

Single-leaf walls made of normal concrete cannot be realized because of the requirements on the thermal insulation of buildings. This leads to the requirement of an external insulation, resulting in considerable disadvantages regarding design, construction, sustainability and economy. Trials to construct single-leaf walls of conventional lightweight concrete resulted in wall thicknesses over 50 cm. The Institute for Structural Concrete (ISC) at the University of Duisburg-Essen and the Institute of Materials Research of the German Aerospace Center (DLR) developed a new lightweight concrete, called “High Performance Aerogel Concrete” (HPAC). HPAC is made by the embedding of silica aerogel granules in a high strength cement matrix. The HPAC exhibits a remarkable relation between compressive strength and thermal conductivity – allowing the production of ENEV-conform exterior walls with a thickness of only 36,5 cm (with a 30 mm thick aerogel insulation plaster on the interior and exterior surface). For a further reduction of the wall thickness a graded structure has been developed, too. HPAC for the load bearing layer contains approx. 50 vol% aerogel and has a compressive strength in the range of normal concrete. In addition to its good thermal insulation properties, HPAC has a good sound absorption coefficient. Despite the low bulk density, the sound absorption coefficient is even better than that of normal concrete. Its suitability as a fire protection material was proven by its classification in the fire resistance class R120. In contrast to the EPS/XPS material, HPAC can be classified as water-repellent and diffusion-impeding. As mechanical properties the compressive strength, modulus of elasticity and splitting tensile strength were determined. The compressive strength is the crucial parameter for the design in the ultimate limit state. Thus, the compressive strength of HPAC was verified by statistical evaluation for practical applications in construction. The results are presented in this paper.

11:30am - 11:33am

Hygrothermal performance of hemp lime concrete embedded with phase change materials for buildings

Arielle Melissa OMEME ADA1, Anh Dung TRAN LE1, Hachmi TOIFANE2, Pierre TITTELEIN2, Laurent ZALEWSKI2, Emmanuel ANTCZAK2, Omar DOUZANE1, Thierry LANGLET1

1LTI, EA 3899 – Université de Picardie Jules Verne, IUT Amiens, Avenue des Facultés – Le Bailly, 80025 Amiens Cedex 1, France; 2Univ. Artois, EA 4515, Laboratoire de Génie Civil et géo-Environnement, F-62400 Béthune, France

The use of bio-based materials is one solution to reduce the environmental impact and fits perfectly to the requirements of High Environmental Quality approach which is a standard for green building in France based on the principles of sustainable development. Among these materials, hemp concrete is one of the most promising. Up to date, the literature reviews show that, this bio-based material which is carbon negative construction material exhibits excellent hygric properties, good insulation capacity and has very low volatile organic compounds emissions. Regarding the thermal properties, hemp concrete has a low thermal inertia compared to load-bearing materials such as concrete, brick, etc. Therefore, this article aims to design a hemp lime concrete (HLC) by adding phase change material (PCM) in order to enhance its thermal inertia. In this study, three different formulations have been considered and compared (in relation with the dry weight of the first formulation without PCM): the first one without PCM, second one incorporating 20% PCM and the third one incorporating 40% PCM named HC+0%PCM, HC+20% PCM and HC+40% PCM, respectively. The hygrothermal properties of these concretes (thermal conductivity, heat capacity, moisture buffer value (MBV)) have been characterized. The measurement of the MBV using the protocol proposed in the Nordtest project and the use of an effective capacitance model allowing to study the impact of moisture buffer value (MBV) on the interior relative humidity variation will be presented. The results obtained show that adding PCM allows to increase significantly the thermal inertia of hemp concrete whilst the MBV of hemp lime concrete with or without PCM remains excellent. Moreover, the numerical results obtained show that the use of hemp lime concrete (with and without PCM) allows the reduction of the indoor relative humidity variation.

11:33am - 11:36am

Hygrothermal Performance of the Building Envelope with Low Environmental Impact: Case of a Hemp Concrete Envelope


1École de Technologie Supérieure (ÉTS), Canada; 2École de Technologie Supérieure (ÉTS), Canada; 3École de Technologie Supérieure (ÉTS), Canada

In Canada, and elsewhere, the construction sector is one of the largest emitters of GHGs and buildings are among the largest energy-consuming sectors after industry and transportation. CO2 emissions and energy consumption are linearly dependent. To improve energy performance of buildings architects and researchers have to improve the building envelope before thinking about mechanical systems, since it accounts for more than 50%. The construction of buildings made of hemp concrete is an old technique that is experiencing a new boom today in France, thanks to its energy performance throughout the life cycle of a building. This strong point allows hemp concrete to be considered as a promising material for sustainable construction in the future. This paper consists in finding an alternative to traditional construction by integrating hemp-based materials to improve the energy and hygrothermal performance of the building envelope. The goal is to evaluate the energy performance of hemp concrete for construction in Montreal, Canada where heating predominates and in Dori, Burkina Faso where air conditioning predominates. Simulation results with WUFI Pro 6.2 for the city of Montreal revealed that this material has an excellent quality of heat and humidity regulation and no problems caused by humidity are detected. For Dori, the internal temperatures of hemp concrete walls are between 22℃ to 24,5℃ compared to those of mud brick and cement block walls, which are between 21℃ to 27℃ respectively 20℃ and 29℃ for external temperatures between 19 ℃ and 45 ℃. As this material is both ecological and efficient, it offers an alternative to traditional construction. It is an excellent material to integrate into the construction and will comply with current and future building codes.

Contact and Legal Notice · Contact Address:
Privacy Statement · Conference: IBPC 2021
Conference Software - ConfTool Pro 2.6.142+TC
© 2001 - 2021 by Dr. H. Weinreich, Hamburg, Germany