Improved Magnesium Cement for Durable Hemp Composite Boards

Hemp concrete is a well-known bio-based building material, but due to its relatively low compressive strength is mainly used as an insulation material with a load-bearing wooden frame. There are possibilities to expand hemp concrete application in construction by substituting traditional lime with magnesium cement. Magnesium oxychloride cement is a material already known for some time and nowadays used in building board production. Strength, lightweight, ease of use are advantages that highlight relatively new magnesium oxychloride type boards compared to traditional sheeting materials such as plywood, gypsum plasterboard and fibre-cement board. Therefore, similar parameters are thought to be reached by producing magnesium oxychloride hemp board. In this work, magnesium cement water resistance was studied and possibilities to improve it was examined by adding fly ash and nanosilica. Among the nanomaterials used in building materials, nanosilica has gained significant interest by performing a beneficial effect in improving the mechanical properties of concretes. In addition, due to its ultrafine size and high chemical reactivity, the performance of nanosilica is much better with a lower amount of admixture required. Results show that applied nanosilica slightly reduced the compressive strength of magnesium cement in a dry state, but at the same time significantly increased its water resistance. Hemp magnesium oxychloride cement board prototype samples were produced and demonstrate promising results for further manufacturing of hemp composite boards.

Axial Compression Behaviour Analysis of Insulated Concrete Form (ICF) Wall Panel with Fibre Cement Board

Nowadays, one of the fastest growing technique is an Insulated Concrete Form (ICF). It has advantages like cost-effective, less maintenance, soundproof, energy-efficient, waterproof and disaster-resistant. ICF wall panels are made by interlocking Fibre Cement Board (FCB) sheet which poured in placed concrete. In this study, the behaviour of the ICF wall panel under axial compression is examined with experimental and analytical methods. ICF wall panels cast with various thickness and dense FCB are tested under axial compression. ICF panels with 1.2gm3/cm dense FCB with changing width of 6mm and 10mm were casted for experimental analysis. The experiments were carried out in an universal testing machine with the capacity of 600 kN. The maximum peak load of 540 kN is observed in FCB of 10mm thick and the maximum displacement of 13mm is observed in FCB80 at the peak load. An analytical investigation is carried with Euler’s crippling load equation and an average variation of 12% is observed between analytical and experimental results. It is concluded that the ICF system of construction provides desirable plastic behaviour against axial compressive loading. Hence ICF is recommended for construction to get the maximum benefits of the wall while it reaches ultimate strain.

Development of Structural Insulated Panels Made from Wood-Composite Boards and Natural Rubber Foam

An experimental study was carried out to develop and examine the properties of a new type of structural insulated panel (SIP). SIP prototypes conducted from this research consisted of insulated foam manufactured from natural rubber filled with wood particles as the core layer and three kinds of commercial wood-composite boards (plywood, cement particleboard, and fiber-cement board) as the surface layers. Polyurethane was used as an adhesive bond between the surface and the core layer. This preformed panel was placed into a clamping device and compressed until adhesive curing was achieved. The physical and mechanical properties of the SIP prototypes were consequently evaluated. The test results indicated that the types of surface layer materials played a significant effect on the SIP properties. The SIP covered with cement particleboard and fiber-cement board revealed high mechanical properties and high water resistance. The SIP prototype covered with plywood showed desirable properties (such as low density, high resistance of screw withdrawal, and low thermal transmittance). However, high water absorption and low fire resistance were drawbacks of the SIP covered with plywood. These properties should be improved.

Reduction of Load Capacity of Fiber Cement Board Facade Cladding under the Influence of Fire

The paper analyzes the issue of the reduction of load capacity in fiber cement board during a fire. Fiber cement boards were put under the influence of fire by using a large-scale facade model. Such a model is a reliable source of knowledge about the behavior of facade cladding and the way fire spreads. One technical solution for external walls—a ventilated facade—is gaining popularity and is used more and more often. However, the problem of the destruction during a fire of a range of different materials used in external facade cladding is insufficiently recognized. For this study, the authors used fiber cement boards as the facade cladding. Fiber cement boards are fiber-reinforced composite materials, mainly used for facade cladding, but also used as roof cladding, drywall, drywall ceiling and floorboards. This paper analyzes the effect of fire temperatures on facade cladding using a large-scale facade model. Samples were taken from external facade cladding materials that were mounted on the model at specific locations above the combustion chamber. Subsequently, three-point bending flexural tests were performed and the effects of temperature and the integrals of temperature and time functions on the samples were evaluated. The three-point bending flexural test was chosen because it is a universal method for assessing fiber cement boards, cited in Standard EN 12467. It also allows easy reference to results in other literature.

Sifat Fisis Dan Keunggulan Papan Semen Dari Limbah Kulit Batang Sagu

This research aimed to determine the physical properties and advantages of cement boards made from sago stem bark waste based on the test results of several parameters according to JIS A 5908 (2003) standard. The results showed that the physical properties of cement board from sago stem bark waste with the addition of the CaCl2 catalyst were good, with the average value of density ranged from 1.19-1.26 gr/cm³, water content 7,67-8,02%, and water absorption after immersion 2 hours 6,03-7.65% as well as after 24-hour immersion 11,62-12,91%, respectively. The averages swelling value of board thickness was 1.62-12,91% after immersion 2 hours and 1.40-3.41% after immersion 24 hours. Furthermore, what sago bark waste in various positions of the tree trunk (tree base, middle and top) can be utilized to manufacture cement board. The board made from sago stem bark waste at the base position with a catalyst CaCl2 6% has the best physical properties and meets JIS A 5908 (2003) standard. Cement board from sago stem bark waste has an excellent waterproof capability and can be used as outdoor materials.

Magnesium oxychloride boards: understanding a novel building material

Magnesium oxide type building boards are a relatively new alternative to traditional sheeting materials such as plywood, gypsum plasterboard and fibre-cement board. They have many advantages; strength, lightweight, ease of use and excellent fire resistance, which has become increasingly important as demanded by industry and required by more stringent legislation. Recently cases of durability issues associated with magnesium oxychloride boards in Denmark have emerged, however the precise nature of the problem was not established. These issues have been related to magnesium oxychloride boards which were exposed to high levels of moisture. In this paper the mechanism of the failures observed in Denmark has been investigated. The difference in quality between various magnesium oxychloride boards available in the market was also studied. It was found that there are significant differences, both physically and chemically, between magnesium oxychloride boards supplied from different manufacturers. Crucially, the performance of each board when exposed to high levels of relative humidity was vastly different. Some of the boards investigated displayed behaviour similar to that observed in Denmark, whilst other boards exhibited substantial resistance to humid environments and had not deteriorated after 60 weeks of exposure.