Use of Hemp Fibres in 3D Printed Concrete

The use of fibres as reinforcement of 3D printed concrete is widely known and applicable in many situations. However, most of the applied fibres are not produced from renewable resources. Natural fibres are commonly considered as an ecological alternative for these fibres. In order to contribute to improvement of the sustainability of 3D printed concrete, natural fibres such as hemp can replace these synthetic fibres. The objective of this study is therefore to study the possibilities of adding hemp fibres for 3D printing purposes. Due to the comparable properties of hemp and synthetic fibres, natural fibres tend to be suitable for printing purposes. Mixes are made at laboratory scale using batches of 1 – 3 kg. The study examines the effect of adding hemp fibres for the mechanical and fresh state properties of hemp-based concrete. Mechanical properties from bending tests and direct tensile tests show comparable properties of mortars containing hemp fibres and mortars containing synthetic fibres. The fresh state behaviour of the designed concrete mix showed promising and comparable results for a mix based on 0.5wt% of hemp fibres. One of the major issues regarding the use of natural fibres is the irregularity and high water uptake of the fibres. Due to its high hydrophilicity natural hemp fibres take up much water and can therefore degrade. For this study the effect of water uptake did not have much influence on the mixing and printing purposes. By printing a wall element on laboratory scale the use of hemp fibre-reinforced 3D concrete is validated.

Analysis of heat and mass transfer in the manufacturing process of instant soy milk using a laboratory scale spray dryer

The events that occur during the drying include heat and mass transfer processes. So based on this, this research will discuss "Analysis of Heat and Mass Transfer in the Process of Making Instant Soy Milk Using a Laboratory Scale Spray Dryer". The research method used is the experimental method. The research that will be carried out will consist of preliminary research and main research. The purpose of this preliminary study was to determine the drying air temperature, fogging pressure, and the ratio of soy milk powder to water in solution. The best results from preliminary research are used in the main study. Data processing using technical analysis. The results showed that an increase in the drying air temperature of 80 ° C, 85 ° C, 90 ° C, 95 ° C, and 100 ° C caused a decrease in the need for drying air, namely 27.323 kg of dry air / hour to 9.840 kg of dry air / hour, time the drying of the material is shorter, namely 1 hour 10 minutes to 1 hour, the increase in thermal efficiency is 81.9% to 84.3%, and the increase in product weight coming out of the drying chamber is 3.1 grams to 4.1 grams. The results of the questionnaire showed that the panelists tended to rank taste first (65%), aroma second (61.25%), color third (47.5%).