Wood-wool Cement Research Articles

Kualitas Papan Semen dari Partikel Bamban (Donax canniformis)

The aim of this research is to determine the influence of mixture rasio of cement/bamban particles on the quality of the cement boards. This research was conducted by four mixture rasio cement/bamban particles (w/w) that was 1.25/1, 1.5/1, 1.75/1 and 2/1. Bamban particles was immersion on hot water (boiling at 100°C) for 3 hours to remove the extractives compounds. The mixture ratio between cement and bamban particles was compressed for 1 hour at a pressure of 30 bar, followed by manual pressure (clamping) for 24 hours. The physical and mechanical properties of cement boards was conducted according to SNI 03-2104-1991 for wood-wool cement boards. The results of the study show that mixture rasio cement/bamban particles has a very significant effect on the quality of the resulting cement boards.

Development of New Bio-Based Building Materials by Utilising Manufacturing Waste

Abstract Over the last decade, research has increasingly focused on reducing the use of natural resources and improving waste management in the construction industry. Various possibilities exist for reducing waste in this sector, ranging from using waste as filler materials to developing new binders and building materials. This study focuses on the development of bio-based building materials using waste from the manufacturing of wood-wool cement boards. The binder and filler materials were obtained from the manufacturing waste and used in this research. The developed materials were tested for their visual appearance, macrostructure, material density, thermal conductivity coefficient and compressive strength. The results showed promising data for the self-bearing bio-based building materials, which had similar thermal properties to other bio-based materials and could be used as thermal insulation materials with a thermal conductivity coefficient of 0.0827–0.1172 W/(mK). The material density of the developed bio-based composites was found to be 430–617 kg/m3. By incorporating manufacturing waste into the production process of bio-based building materials, it becomes evident that overall waste from manufacturing plants can be significantly reduced, and the sustainability aspect of wood-cement board manufacturers can be enhanced.

Acoustical treatment characterization of a classroom with wood-based composites

The built environment might be acoustically treated in different ways in terms of complexity and cost. This research proposes an alternative for the acoustical treatment of an existing classroom through the insertion of wooden composites (i.e. panels) which were attached on the walls. This proposition sought to demonstrate an alternative that was easy in the context of implementation and feasible from the perspective of sustainability and cost. Industrialized wood composites from the south part of Brazil were chosen, such as the MDF (Medium Density Fiberboard), the OSB (Oriented Strand Board) and the WWCB (Wood-Wool Cement Board) with different thicknesses. In a acoustically treated classroom, the reverberation time (T20) and the Speech Transmission Index (STI) were evaluated as objective parameters. Three-dimensional models were built and validated with measurements using an open source software (I-SIMPA) in order to identify which scheme could provide the optimal T20. In order to complement the analysis, subjective tests were carried out with a sample of men and women to determine the Word Discrimination Testing (WDT) applied to the classroom environment. WWCB-type panels increased the STI values at different seats over the classroom and the analysis of the Sound Pressure Levels (SPL) distribution along the seats led to the conclusion that there was no excessive absorption of high-frequency energy. Finally, the subjective tests proved that the WWCB type (50.0 mm thick) improved the speech intelligibility.

Sound insulation of a hollow concrete blocks wall made with construction and demolition waste and wood-based panels as linings

It is a well-discussed topic that Construction and Demolition Waste (CDW) can be recycled and used as aggregate in the construction sector. Generally, Brazilian construction techniques are based on hollow blocks or bricks and mortars as coating systems. This paper describes the sound insulation of a masonry wall built with hollow concrete blocks and CDW as aggregates. The measurements were performed according to the reverberant chamber method. Keeping sustainability in mind instead of applying cement mortar as coating system, Oriented Strand Boards (OSB) and Wood-Wool Cement Boards (WWCB) were used and also tested as acoustical linings. The panels were directly attached on the wall with nails in the receiving room. All types of panels increased the weighted sound reduction index ([Formula: see text]). Wood-based composites can also improve the air quality because of their hygroscopic properties. In summary, sustainable wall systems were characterized according to their sound insulation properties, presented as possible substitutes for traditional masonry walls.

Enhanced Resistance to Fire of the Bark-Based Panels Bonded with Clay

The aim of this study was to investigate the flammability of ecologically friendly, 100% natural larch and poplar bark-based panels bonded with clay. The clay acted as a fire retardant, and it improved the fire resistance of the boards by 12–15% for the surface and 27–39% for the edge of the testing specimens. The thermal conductivity was also analyzed. Although the panels had a density ranging from 600 to 900 kg/m3, thermal conductivity for the panel with a density of 600 kg/m3 was excellent, and it was comparable to lightweight insulation panels with much lower densities. Besides that, the advantage of the bark clay boards, as an insulation material, is mostly in an accumulative capacity similar to wood cement boards, and it can significantly improve the climatic stability of indoor spaces that have low ventilation rates. Bark boards with clay, similar to wood cement composites (wood wool cement composites and wood particle cement composites), have low mechanical properties and elasticity. Therefore, there their use is limited to non-structural paneling applications. These ecologically friendly, 100% natural and recyclable composites can be mostly used with respect to their thermal insulation, acoustics and fire resistance properties.

The recycling potential of wood waste into wood-wool/cement composite

Nowadays, the recycling potential of wood waste is still limited and in a resource cascading approach, recycling wood waste in cement composite materials, such as wood wool cement board (WWCB) appears as a promising solution. The quality of the wood waste is the main factor leading to the instability of the final product which can affect the mechanical properties or the wood cement compatibility. However, the possibility to recycle wood waste as a spruce replacement for WWCB manufacture needs more investigation in order to assess the impact of wood waste on the mechanical performances of the final product, but also to characterize the behavior of hazardous substances embodied in a cement matrix. This paper addresses the characterization of two types of wood waste, from pallets and demolition waste and their influence on the manufacturing process, mechanical properties and chemical compatibility when used in WWCB. A comprehensive approach is provided to define the influence of wood waste on the hydration reaction of the cement and the chemical and physical properties of the composite are assessed by isothermal calorimetry, leaching measurement and microscopy. Finally, the mechanical properties of WWCB are tested for different wood waste content in order to define the best wood/wood waste ratio and thereby confirming the possibility to reuse the wood waste in fiber/cement composite for building application.

Investigation of local degradation in wood stands and its effect on cement wood composites

Wood-wool cement boards (WWCB) are a type of cement/fibre composite using wood strands as reinforcement. When lignocellulosic materials such as wood are mixed with cement, polysaccharides can leach out and negatively affect the cement hydration. Thus, the WWCB industry has to face those problems, which can cause significant problems during the manufacturing process. This study aims to identify the parameters that can influence the quality of wood and thus the WWCB. The investigation focuses on the potential differences between these two wood samples, by analysing the cement/wood compatibility, the mechanical properties of the wood strands, the microstructure and the chemical composition of the leachates. Two similar spruce wood samples, which have been grown and harvested under the same conditions are compared to each other. When mixed with cement, one sample performed up to expectation in WWCB whereas the second one shows chemical and mechanical problems, resulting in weak WWCBs that cannot fulfil the standards. A comparison two wood samples shows not only different properties of WWCB. Cement-fibre compatibility for one of the sample is below the limit to be used in composite and tensile strength shows a similar behaviour.

MSWI bottom ash as binder replacement in wood cement composites

Nowadays, the incineration of municipal solid waste (MSW) is widely applied, as it reduces the waste 90% by volume and 80% by mass. The main by-product coming from the MSW incineration is bottom ash (BA). Despite numerous studies concerning the uses of this by-product in the construction field, BA is not widely applied because of two main concerns: (1) the disadvantageous morphology of the particle, leading to a high porosity and water absorption and (2) the presence of harmful contaminants, leaching out from the by-product. Because of its porous structure, BA can be suitable as binder replacement for improving insulation properties of wood composites, usually requiring low flexural strength. Therefore, this study will evaluate the influence of a porous binder containing BA and cement on wood wool cement boards (WWCB). The BA and cement are chemically and physically characterized. Thereafter, cement pastes with different replacement levels of BA (0–50%) are produced to measure mechanical and thermal properties. The same mixes are then used to make WWCB. While the thermal conductivity remains unchanged, the mechanical properties benefit from the use of BA up to 30% wt. due to the reduced macro porosity of the final composite.

Behaviour of Walls Constructed using Kelempayan (Neolamarckia cadamba) Wood Wool Reinforced Cement Board

This research investigated the behaviour of walls produced from wood wool cement board (WWCB) which were reinforced with a lesser known commercial timber, Kelempayan, when subjected to compression load. Kelempayan timbers were shredded into wood wool and used as reinforcement agent in this study. WWCB having dimensions of 600 × 2400 × 50 mm and 600 × 2400 × 75 mm, respectively, were fabricated. Properties of the WWCB samples, namely swelling, bending and compression strength were tested. 75 mm WWCB has higher fracture toughness but lower strength compared to 50 mm WWCB. Four types of wall systems with different type of configuration were produced and the test results were compared focusing on their value of ultimate load and failure mode. Walls that constructed without application of link and plaster displayed the poorest performance. Plastered and linked wall had the highest ultimate load and comparable with other load bearing walls. The results suggested that walls constructed using WWCB reinforced with Kelempayan wood wool are suitable for load bearing as they exhibited comparable properties when compared to the other load bearing walls such as masonry and straw bale wall.

Axial compression behaviour of reinforced wallettes fabricated using wood-wool cement panel

Wood-wool cement composite panel (WWCP) is one of wood based composite material that produced in a stable panel form and suitable to be used as building wall system to replace non-ecofriendly material such as brick and other masonry element. Heavy construction material such as brick requires more manpower and consume a lot of time to build the wall panel. WWCP is a lightweight material with a density range from 300 kg/m3 to 500 kg/m3 and also capable to support an imposed load from the building. This study reported on the axial compression behaviour of prefabricated reinforced wallettes constructed with wood-wool cement panel. A total of six specimens were fabricated using two layers of cross laminated WWCP bonded with normal mortar paste (Portland cement) at a mix ratio of 1:3 (cement : sand). As part of lifting mechanism, the wallettes were equipped with three steel reinforcement (T12) that embedded inside the core of wallettes. Three replicates of wallettes specimens with dimension 600 mm width and 600 mm length were fabricated without surface plaster and with 16 mm thickness of surface plaster. The wallettes were tested under axial compression load after 28 days of fabrication until failure. The result indicated that, the application of surface plaster significantly increases the loading capacity about 35 % and different orientation of the panels improve the bonding strength of the wall.

Static in-plane shear behaviour of prefabricated wood-wool panel wallettes

The green construction material and technique are the current issue toward improving sustainability in the construction industry in Malaysia. The use of construction material that produced from renewable resources is a part of the effort for greening this industry. WWCP (Wood-wool cement panel) is a wood based product available to the construction industry to be used as a structural building wall element. This renewable material has the potential to replace the less eco-friendly materials such as bricks and other masonry element. However, the behaviour of wall subjected to the different load conditions is not well established and therefore, this study aimed to investigate the structural behaviour of the small scale wall (wallettes) subjected to in-plane lateral load. As a comparison, two types of fabrication technique of wallettes with dimension of 1200 mm × 1200 mm (± 30 mm) were considered. The conventional vertical stacking technique was denoted as W1 and new propose techniques (cross laminated) was denoted as W2. Three replicates of each type were fabricated and tested under in-plane lateral load until failure. The test results revealed that, the wallettes fabricated using the new fabrication technique significantly increased two times in load carrying capacity compared to wallettes with conventional technique.

Influence of the spruce strands hygroscopic behaviour on the performances of wood-cement composites

In wood wool cement composites, the influence of natural fibres is the main factor leading to the instability of the final product. During the manufacture, small variations in wood properties result in inhomogeneous density and strength of the boards. Among the accountable factors, the hygroscopic behaviour of the wood can deeply affect the cement hydration. However, the competitive water absorption mechanism between wood strands and cement is not fully understood. This paper will address the absorption behaviour of wood wool strands in combination with cement. A model for calculating the water to binder ratio of the paste in presence of wood is proposed and validated by NMR and isothermal calorimetry. Finally, the mechanical performances of the composites are tested for different water amounts, verifying the proposed model and defining the conditions for the optimal bending strength.

Effect of the morphology and pore structure of porous building materials on photocatalytic oxidation of air pollutants

This study focuses on the effect of the morphology and the pore structure of two different porous substrates, namely wood-wool cement board (WWCB) and autoclaved aerated concrete (AAC), on the air pollutant removal efficiency by photocatalytic oxidation (PCO). Their rough surface and porous structure make them appealing choices for nitric oxide (NO) de-pollution, under indoor conditions. In-depth material characterization of the two substrates is realized in order to understand the effect of the porosity, roughness and surface area on the PCO efficiency, at different air flow rates. PCO assessment shows that both activated substrates can degrade up to 99% of NO. The morphology and pore structure analyses of the two substrates reveal that a high effective area and roughness increases the PCO efficiency and an open pore structure allows a better air flow, avoiding NO2 release.

Axial compression behaviour of cross laminated wood-wool panel wallettes

This study reported on the investigation of the structural behaviour of wallettes fabricated using wood-wool cement panel (WWCP) under axial compression load. WWCP is a wood based product, which produced by mixing a wood-wool, cement and water and compressed to form a stable panel with dimension of 600 mm × 2400 mm × 50 mm. In the fabrication of wallettes, two parameters were considered which are wallettes without surface plaster denoted as WNP and wallettes with 16 mm thickness of surface plaster on both sides denoted as WP. The 50 mm thickness of WWCP was used and cut into size 300 mm and 600 mm length. The cut panels were then horizontally laid in two layers (each layer consists of two panel strips) at different panel orientation to form a 600 mm × 600 mm wallettes. The front and rear layer were bonded together using 15 mm thick of normal mortar mix at a mixing ratio of 1: 3 (Cement : Fine sand). A total of five wallettes specimens were fabricated and tested under axial compression load test until failure. The testing results indicated that, the application of surface plaster on both side significantly increased the load carrying capacity of wallettes about 31 % compared to the wallettes without surface plaster.

Modelling and optimization of the sound absorption of wood-wool cement boards

The present article aims to characterize and improve the sound absorption of wood-wool cement boards (WWCB) with varying strand widths, densities, thicknesses and applied with varying air cavity thicknesses by using impedance models. Different rigid-frame impedance models were analysed to predict the acoustic impedance of this material, and their suitability for the WWCB was evaluated. The Johnson-Champoux-Allard (JCA) model with its parameters, porosity, flow resistivity, tortuosity and characteristic lengths, was found to be the most appropriate to model the normal incidence sound absorption. The relations between the bulk density of the board and the impedance model parameters are established for material characterisation and optimization. Optimum density values were found per strand in terms of the sound absorption in the frequency range 200–2500Hz. Moreover, the use of a density variation in the boards leads to improvement of the sound absorption. Regarding the application of the board, the use of an air cavity with a thickness of 100mm leads to an optimized sound absorption for every strand width.

Assessing the effect of CaSO4 content on the hydration kinetics, microstructure and mechanical properties of cements containing sugars

This article aims to study the hydration kinetics of cements containing sugars. The effects of Portland cement constituents (including aluminate and ferrite phases and CaSO4 content), and a sugar (glucose) on the hydration kinetics, microstructure and mechanical properties, were evaluated. The heat release during the hydration was analysed using an isothermal calorimeter. The reaction’s products, gel structure and microstructure at different hydration times were analysed by the analytical methods XRD, FTIR and SEM. Furthermore, mortars and wood-wool cement composites were designed to validate the present findings. It is concluded that the newly derived binder can overcome retarding effects and result in wood-wool cement composites with excellent performance.

The Engineering Properties of Wood-Wool Cement Walls

Taiwan is situated in the seismic belt and belongs to the subtropical climate. The abilities of heat insulation and seismic resistant of buildings in Taiwan were become more and more important. Fundamentally, it should develop a new materials suitable for use in hot and humid environment. This research aims to study the engineering properties of the wood-wool cement and compare with those of traditional building materials. The test results show that the unit weight of wood-wool cement boards is about 615 kg/m3. The wood-wool cement boards collocate with the light-weight rigid frame and paste those construct the wood-wool cement light wall, its unit weight will increase to about 1580 kg/m3; Compare with the unit weight 2300 kg/m3 concrete, the unit weight of wood-wool cement boards and light wall will decrease 73% and 31%, respectively. The wood-wool cement light wall is not only beneficial to convenience of construction but also increase the load-bearing capacity of buildings, future more, it is contribute to reduce the seismic force. The thermal conductivity of wood-wool cement boards and the wood-wool cement light wall are about 0.09 kcal/m-hr-°C and 0.58 kcal/m-hr-°C, which compare with the test result, 1.25 kcal/m-hr-°C of concrete with compressive strength 210 kg/cm2 are obviously decrease. As bending strength and wind pressure test that we know, the wood-wool cement light wall is worse than reinforced concrete. But the mechanics of the wood-wool cement light wall corresponds to the wallboard strength requirement of Taiwan Building Code. From the economic analysis, the wood-wool cement boards possess higher economic benefits due to better energy efficiency. As we know from the above, it can be expected soon to use the wood-wool cement light wall in buildings.

Development of New Prefabricated Wall Constructed Using Wood-wool Cement Composite Panel

Sustainability in construction industry has brought new materials to be used as a wall element in building construction in Malaysia. Wood-wool cement composite panel (WWCP) is the wood based product which manufactured from renewable resources, less embodied carbon emission, lightweight, easy to process and fabricate and available to the construction industry to replace less eco-friendly materials such as common brick and other masonry element. In Malaysia, there are increasing interest in using WWCP as a wall element in building construction, however the structural performance under imposed load and the installation technique using this material still not well established. Therefore, this study aims to improve the sustainability in building construction with the development of new prefabricated wall constructed using wood-wool cement composite panel. Two types of fabrication techniques are considered in fabricating prefabricated wallettes with dimension of 1200mm x 1200mm (± 30mm). The wallettes type W1 is the current practiced technique, meanwhile wallettes type W2 is the new proposed fabrication technique. Three replicates of each type of wallettes were then tested under axial compression load in order to investigate their structural performance. The results of experimental testing showed that, the wallettes fabricated using the new fabrication technique significantly increased two times in load carrying capacity compared to wallettes with current practiced technique.

Mechanical properties of hierarchically structured wood–cement composites

Wood wool cement composites (WWCC) are widely used materials constituted of wood wool and Portland cement. The material presents excellent mechanical, chemical and biological properties. However, the understanding of its mechanical behavior is rather limited. In this contribution, a hierarchically structured model is presented to describe the mechanical behavior of WWCC under compressive stress. The material is modeled as 3D rigid open cellular structured material, 2D randomly oriented triple laminated material and particulated+fibrous material in the cm, mm and μm scales, respectively. The outcome of the model is a set of mathematical expressions permitting to predict the stress–strain behavior of the material in two cases: wood strands parallel and perpendicularly oriented to the stress direction. Mechanistically, the model predicts failure by buckling at the mesoscale. A statistical experimental work is included and used to validate the model.

Axial Compression Behaviour of Wallettes Constructed Using Wood-Wool Cement Composite Panel

This paper reports on the investigation of the structural behavior of wallettes made from wood-wool cement composite panel (WWCP). Initially, a series of experimental test were carried out to investigate the mechanical properties of WWCP namely density, bending properties (MOR and MOE), compressive strength and tensile strength for two thicknesses of WWCP (50 mm and 100 mm). Then, the axial compression capacity of WWCP was investigated using wallettes. In the fabrication of wallettes, there are two types of panel arrangement considered and denoted as W1 and W2. For W1, 100 mm thick WWCP was used and cut into size of 300 mm width and 600 mm length. The cut panels were then stacked vertically (two layer) in running bond pattern to form a 600 mm x 600 mm wallettes. The top and bottom panels were connected together with 10 mm thick mortar paste and three vertical steel bars were inserted between panels. In addition to this, an enhancement has been made by fixed two U-Nail at the connection area on each side of wallettes. For W2, a new panel arrangement technique has been proposed by integrating two layers of 50 mm thickness of WWCP (cut into size of 300 mm width and 600 mm length) with different orientation of panel arrangement to form a 600 mm x 600 mm wallettes. The front side of the panels has been arranged in the longitudinal direction, whereas back side in transverse direction. The front and back side panels were bonded together using either adhesive or mortar mix with different thicknesses to form approximately 100 mm (± 15 mm) thick wall. For mechanical properties of WWCP, it was found that, the strength properties of the panel decreases with the increased in panel thickness. For the axial compression test of wallettes, the results showed that, a new proposed of panel arrangement technique with mortar mix significantly improved the stability as well as increased load carrying capacity of wallettes.