Water water should be clean and free from deleterious

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Water Water should be clean and free from deleterious matter and should meet relevant standards for water to be used to mix concrete. Potable water is normally suitable. Pozzolanic materials PFA, GGBS, Metakaolin, Microsilica and ground glass powder are a range of pozzolanic materials that can be used to partially replace cement either to have a beneficial effect on the properties of GFRC or for the environmental concerns. They work by reacting with the free lime produced during the hydration process to form further hydration products. Sand and aggregating for facing When a facing mix is used to produce an architectural finish special aggregates and sand may be required. They should be clean, hard, strong, durable and inert, and free of staining or deleterious material. Crushed and graded hard rocks like limestone, granite, spar, calcite or marble are particularly suitable. Admixtures Admixtures such as water reducers, accelerators, retarders and air entraining agents may be used to impart specific properties to GFRC. They can be standard concrete admixtures or those specially formulated for GFRC manufacture. Polymer Acrylic thermoplastic polymer is added to the GFRC mix to allow for a subsequent dry cure and for property enhancement, particularly the reduction of surface crazing. It is particularly favoured, when white cement is used, to avoid the possible water stain from wet cure. Pigments Powder pigments or dispersions may be used to achieve specific colour effect. They are normally iron oxide based and should be harmless to concrete strength and set, temperature stable, non-fading and alkali resistant. The dosage should not exceed 10% of amount of cement. Paints and sealers Paints and sealers may be applied to GFRC. Latex masonry paints and water resistant stains in a methylemethacrylate base offer a wide range of colour choices. A clear coating of silane or siloxane may be applied to the face and back surfaces of a panel to reduce moisture movement and efflorescence. [1] 2.3. Use of GFRC – environmental properties The world of design nowadays is faced with numerous choices when it comes to ecological design and construction. “Green” materials and techniques are ubiquitous, presented in every phase of design,
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WMCAUS 2018 IOP Conf. Series: Materials Science and Engineering 471 (2019) 082054 IOP Publishing doi:10.1088/1757-899X/471/8/082054 4 what is no longer a novelty. Designers are aware of the fact, that everyday decisions concerning materials and methods will impact our future generations. The GFRC components are environmental friendly. The glass elements are from reclaimed or recycled materials, and the cement mix includes fly ash, which is the waste produced by industrial smokestacks. The finishes are ecologically friendly water-based materials that give off no pollutants or toxins when produced. Using GRC is friendly on the environment and goes hand-in-hand with the current “green building” push. [2] GRC contains materials that, taken from the soil, have no adverse effect on the environment. Concrete’s components include Fly Ash, Silica Sand, Portland cement and
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  • Fall '19
  • GFRC

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