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Cement-bonded wood fiber is a composite material manufactured throughout the world. It is made from wood (usually waste wood), chipped into a specially graded aggregate that is then mineralized and combined with Portland cement. Combination of wood and cement paste has been shown to result in a degradation (hydrolysis) of wood (or any other ligno-celullosic particles) components, namely hemicellulose and lignin [1] [2] .
Cement-bonded wood fiber is used to manufacture a wide variety of products primarily for the construction industry (products like insulating concrete forms, siding materials and noise barriers).
Cement bonded wood fiber materials can be classified as low density, medium density and high density. The density of the material will determine to a large extent, the various properties of the end product. Other factors determining the overall performance of a cement bonded wood fiber material are:
Most common is low-density cement bonded wood fiber. It is known for its use in LEED-certified projects and other types of green building. The material itself is 100% recyclable[ citation needed ], and is known for its insulating and acoustic properties.
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Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to a solid over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminium combined.
In materials science, a metal matrix composite (MMC) is a composite material with fibers or particles dispersed in a metallic matrix, such as copper, aluminum, or steel. The secondary phase is typically a ceramic or another metal. They are typically classified according to the type of reinforcement: short discontinuous fibers (whiskers), continuous fibers, or particulates. There is some overlap between MMCs and cermets, with the latter typically consisting of less than 20% metal by volume. When at least three materials are present, it is called a hybrid composite. MMCs can have much higher strength-to-weight ratios, stiffness, and ductility than traditional materials, so they are often used in demanding applications. MMCs typically have lower thermal and electrical conductivity and poor resistance to radiation, limiting their use in the very harshest environments.
Fiber is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate fibers, for example carbon fiber and ultra-high-molecular-weight polyethylene.
Engineered wood, also called mass timber, composite wood, man-made wood, or manufactured board, includes a range of derivative wood products which are manufactured by binding or fixing the strands, particles, fibres, or veneers or boards of wood, together with adhesives, or other methods of fixation to form composite material. The panels vary in size but can range upwards of 64 by 8 feet and in the case of cross-laminated timber (CLT) can be of any thickness from a few inches to 16 inches (410 mm) or more. These products are engineered to precise design specifications, which are tested to meet national or international standards and provide uniformity and predictability in their structural performance. Engineered wood products are used in a variety of applications, from home construction to commercial buildings to industrial products. The products can be used for joists and beams that replace steel in many building projects. The term mass timber describes a group of building materials that can replace concrete assemblies.
Building material is material used for construction. Many naturally occurring substances, such as clay, rocks, sand, wood, and even twigs and leaves, have been used to construct buildings and other structures, like bridges. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic. The manufacturing of building materials is an established industry in many countries and the use of these materials is typically segmented into specific specialty trades, such as carpentry, insulation, plumbing, and roofing work. They provide the make-up of habitats and structures including homes.
Wood–plastic composites (WPCs) are composite materials made of wood fiber/wood flour and thermoplastic(s) such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), or polylactic acid (PLA).
Particle board, also known as particleboard or chipboard, is an engineered wood product, belonging to the wood-based panels, manufactured from wood chips and a synthetic, mostly formaldehyde based resin or other suitable binder, which is pressed under a hot press, batch- or continuous- type, and produced. Particle board is often confused with oriented strand board, a different type of fiberboard that uses machined wood flakes and offers more strength.
Aggregate is the component of a composite material that resists compressive stress and provides bulk to the composite material. For efficient filling, aggregate should be much smaller than the finished item, but have a wide variety of sizes. Aggregates are generally added to increase the strength of composite materials. For example, the particles of stone used to make concrete typically include both sand and gravel. Many construction cement add in aggregates to increase its mechanical strength. Aggregates make up 60-80% of the volume of concrete and 70-85% of the mass of concrete.
Hardboard, also called high-density fiberboard (HDF), is a type of fiberboard, which is a pressed wood or engineered wood product. It is used in furniture and in the construction industry.
Fiberboard or fibreboard is a type of engineered wood product that is made out of wood fibers. Types of fiberboard include particle board or low-density fiberboard (LDF), medium-density fiberboard (MDF), and hardboard or high-density fiberboard (HDF).
Ceramic engineering is the science and technology of creating objects from inorganic, non-metallic materials. This is done either by the action of heat, or at lower temperatures using precipitation reactions from high-purity chemical solutions. The term includes the purification of raw materials, the study and production of the chemical compounds concerned, their formation into components and the study of their structure, composition and properties.
Fiber-reinforced concrete or fibre-reinforced concrete (FRC) is concrete containing fibrous material which increases its structural integrity. It contains short discrete fibers that are uniformly distributed and randomly oriented. Fibers include steel fibers, glass fibers, synthetic fibers and natural fibers – each of which lend varying properties to the concrete. In addition, the character of fiber-reinforced concrete changes with varying concretes, fiber materials, geometries, distribution, orientation, and densities.
A cement board is a combination of cement and reinforcing fibers formed into sheets, of varying thickness that are typically used as a tile backing board. Cement board can be nailed or screwed to wood or steel studs to create a substrate for vertical tile and attached horizontally to plywood for tile floors, kitchen counters and backsplashes. It can be used on the exterior of buildings as a base for exterior plaster (stucco) systems and sometimes as the finish system itself.
Filler materials are particles added to resin or binders that can improve specific properties, make the product cheaper, or a mixture of both. The two largest segments for filler material use is elastomers and plastics. Worldwide, more than 53 million tons of fillers are used every year in application areas such as paper, plastics, rubber, paints, coatings, adhesives, and sealants. As such, fillers, produced by more than 700 companies, rank among the world's major raw materials and are contained in a variety of goods for daily consumer needs. The top filler materials used are ground calcium carbonate (GCC), precipitated calcium carbonate (PCC), kaolin, talc, and carbon black.
Textile-reinforced concrete is a type of reinforced concrete in which the usual steel reinforcing bars are replaced by textile materials. Instead of using a metal cage inside the concrete, this technique uses a fabric cage inside the same.
Cellulose fibers are fibers made with ethers or esters of cellulose, which can be obtained from the bark, wood or leaves of plants, or from other plant-based material. In addition to cellulose, the fibers may also contain hemicellulose and lignin, with different percentages of these components altering the mechanical properties of the fibers.
Aerogels are a class of synthetic porous ultralight material derived from a gel, in which the liquid component for the gel has been replaced with a gas, without significant collapse of the gel structure. The result is a solid with extremely low density and extremely low thermal conductivity. Aerogels can be made from a variety of chemical compounds. Silica aerogels feel like fragile styrofoam to the touch, while some polymer-based aerogels feel like rigid foams.
Textile-reinforced mortars (TRM) (also known as fabric-reinforced cementitious mortars are composite materials used in structural strengthening of existing buildings, most notably in seismic retrofitting. The material consists of bidirectional orthogonal textiles made from knitted, woven or simply stitched rovings of high-strength fibres, embedded in inorganic matrices. The textiles can also be made from natural fibres, e.g. hemp or flax. When combining plant fibers with mortars, one must pay attention to potential hydrolysis of hemicelluloses and lignin.
A fiber-reinforced cementitious matrix (FRCM) is a reinforcement system composed by fibers embedded in an inorganic-based matrix, usually made by cement or lime mortar. Plant fibers are a promising area but they are subjected to degradation in the alkaline environment and elevated temperatures during cement hydration.
Wood degradation is a complex process influenced by various biological, chemical, and environmental factors. It significantly impacts the durability and longevity of wood products and structures, necessitating effective preservation and protection strategies. It primarily involves fungi, bacteria, and insects. Fungi are the most significant agents, causing decay through the breakdown of wood's structural components, such as cellulose, hemicellulose, and lignin. Chemical degradation is likewise significant. Degradation of wood in a concrete matrix is mostly attributed to the affect of alkaline environment and hydrolysis of lignin and hemicellulose and and elevated temperatures may accelerate the degradation process of the cell walls.
