This thesis addresses the performance based design and development of an environmentally friendly calcium sulfate-based indoor building product towards an improved indoor air quality. Here "environmental friendly" is referred to the environment related subjects including: (1) the selection of raw materials to decrease the environmental impact caused by their production process; (2) an enhanced thermal comfort resulted from the newly developed composite; (3) the removal function of air pollutants resulted from the newly developed product. Fundamental research on the used materials (calcium sulfate system) is carried out before applying them into the new development in order to gain a deeper understanding of their properties. The water demand of the used CaSO4¿0.5H2O is determined by the mini-slump flow test. The hydration process of the CaSO4¿H2O system is studied by the ultrasonic wave velocity method. The thermo physical properties of the CaSO4¿H2O system are investigated by both experiments and modeling in different conditions (for instance at room temperature and elevated temperatures). Based on the gained knowledge about the materials, a novel calcium sulfate-based lightweight composite is designed applying a mix design concept which was originally developed for concrete design. Lightweight aggregates are used in the mix in order to obtain low density and low thermal conductivity. Multiple experiments are performed to investigate the newly developed composite, including: fresh state behavior, mechanical properties, physical properties, thermal properties and fire behavior. Is it wise to use calcium sulfate as binder? This thesis tries to answer this question by not only investigating the developed calcium sulfate-based composites, but also through a thorough comparative study with cement-based composites developed in the present study. Indoor thermal comfort is related to the indoor temperature which is strongly affected by the heat transfer between indoor and outdoor environment. This is addressed by the low thermal conductivity achieved from the newly developed composite. Indoor air pollutants are one of the most influential factors affecting the indoor air quality. This is addressed in the development of the new product by applying heterogeneous photocatalytic oxidation technology to remove indoor air pollutants. A modified TiO2 is applied here as the photocatalyst for the indoor photocatalytic oxidation (PCO). Experimental results proved the positive effect on the indoor air quality by PCO. A kinetic reaction rate model is built to further understand the PCO working principle and computational fluid dynamics is employed to model the used PCO reactor, enabling the application of this technology to other geometries and flow conditions.
|Qualification||Doctor of Philosophy|
|Award date||3 May 2012|
|Place of Publication||Eindhoven|
|Publication status||Published - 2012|