First Step towards the Upscaling of the Production of Washing Fines - Hemp Composite. Study of Multiphysical Properties

This study investigates the feasibility of scaling-up to industrial scale the production of washing fines – hemp composite. In previous studies (Mazhoud, 2017), (Mazhoud et al., 2017), such composites were developed with a high control of formulation. The washing mud were fully dried, and then milled. The washing fine – hemp composites were prepared from stabilized washing fine and hemp. This study aims to reduce the mud conditioning process in order to save energy and time. In a first time, the methodology for the conditioning of washing mud is detailed. Composite are then prepared considering unstabilized matrix and stabilized matrix with three stabilizer to fine mass ratios (5, 10 and 20 %). The apparent density increases with stabilizer to fine mass ratios according a degree two polynomial law. The mechanical compressive strength increases linearly with apparent density and the performance allows the studied composites to be used as wall formulation regarding the French national rules for hemp concrete. The thermal conductivity values range from 0.107 to 0.123 W/(m.K) at (23°C; 50%RH) reached from production point, this corresponds to a mass water content about 6%. Like for mechanical compressive strength, the thermal conductivity is mainly induced by apparent density. These thermal conductivity values make studied composite suitable for use as distributed insulation or thermal corrector. On hygric point of view, the Moisture Buffer Values classify all formulations as excellent hygric regulators. Finally, this paper shows the feasibility of scaling-up and that multi-physical properties of produced composites make them suitable for use in building envelop. The HSC-10 formulation seems to be the most promising regarding MBV results and considering that it would be possible to reduce thermal conductivity by acting on implementation in order to reduce apparent density.

Energy in buildings: A review of models on hygrothermal transfer through the porous materials for building envelop

The hygrothermal transfer is very important for the design of a building envelope for thermal comfort and economic and energy analysis of the building envelope. The applications of various materials in building envelope have been studied extensively. The study presents several models for the hygrothermal transfer for various building walls. Several energy and mass conservation equations with different boundary conditions and input considerations were presented in this paper for concrete, bricks and wooden walls. The effect of hysteresis was ignored in developing most model equations, while few considered flow pattern of fluid through the wall surfaces. Due to the flexibility of Luikov models, it formed the basis for modelling the coupled heat and mass transfer for porous material independent of hygroscopic nature with different boundary conditions defined according to the geometry and orientations. The influence of type of wall, orientation, thickness, the density of the material and climatic variations on the temperature and moisture evolutions within the building materials was more pronounced. Literature, presenting imaging models using imagery software like COMSOL multi-physics, CFD etc. were scarce considering that microscopic imagery is now deployed to measure the heat and moisture evolution in materials. Future models should include shrinkage or expansion influence on the fibrous material like wood due to their behaviour under environmental condition.

The Influence of Building Envelop Materials on its Life Cycle Performance: A Case Study of Educational Building in Thailand

The analysis of life cycle energy (LCE) and life cycle carbon (LCC) of building were performed in this study in order to identify the solutions for reducing energy-related carbon emission throughout building life time. The influence factors associated with building envelop materials (wall, insulation, window, window-to-wall ratio) were evaluated. The result showed that operation phase contributed a vast majority (>90%) of LCE and LCC. Only 4% emissions saving could be achieved if autoclaved aerated concrete block, cellulose insulation and triple glazing were implemented with WWR of 0.17. The finding suggested that reducing carbon emission should not only be prioritized through use of high energy efficient materials/technologies but should also integrate energy saving measures since energy demand in tropical country is quite high for cooling building. In addition, increasing a possibility and feasibility for supplying renewable energy should be further investigated importunately.