| dc.description.abstract | Stone materials for their inherited advantages and performances including fire proof, wear withstanding, bright and elegance have been comprehensively applied in constructional works. Though ultra large size of stone plates in thickness of 3 cm are now used for the curtain walls of buildings and stone materials for the flooring, stone sculptures and decoration purposes have been rapidly developed, many difficulties are challenging the engineering technology and maintenance. Therefore, basic requirements of being lighter, thinner, higher strength, and larger plate of stone materials have become the bottleneck for the future constructional materials to break through.
Functional composite stone materials, as the subject of the study, utilize the recycling of residual stone materials after the cutting process are to be further crashed, screened, cleaned, added with quartz of higher hardness, coloring and modified with additives in a refined batching; then mixed with epoxy resin to be compressed and molded under vacuum and vibration conditions. Wherein, nanometer powder modifier can be filled in the resin to form an extremely refine structure thus to improve bending strength and impact resistance for the functional composite stone materials to give advantages of being resilient, lightweight and yielding high tensile strength to meet the trends and sustainable development of ultra think stone sheets.
Modifier added into the functional composite stone materials is comprised of light storage, nanometer photothermal catalyst and special ceramic additives. Finally, the stone material is given surface treatment to provide features of stopping ingression of water containment, increasing brightness and hardness, becoming luminous in darkness, generating ions, bacteria resisting by photo-catalyst and self-cleaning, so to eliminate defectives including whitening, rust stains and water seepage found with the current natural stone materials.
Study results show that (1) given with the design conditions of refined batching and the least glue containment, addition of resin modifier and filler of nanometer fine materials will improve compression resistance over 1500 kg/cm², and bending strength over 500 kg/cm². (2) Addition of nanometer fine materials gives even more refined structure for the functional composite stone materials. The surface gloss of the stone materials after polishing could reach over 80, Mohr’s hardness over 8, and water absorption rate greater than 0.02%, all better than those found with the natural marble. (3) XRD and SEM, and AFM microscopic analysis indicate that TiO2 crystals in conic form are found on the surface of the functional composite stone materials that provides self-cleaning function of photo-catalyst. (4) Addition of 15% light storage material permits the duration of 0.3 mcd/cm² effective brightness up to 12 hours, making it an ideal candidate material for the making of marker during night hours and indicator of emergency evacuation. (5) The ratio by weight of the recycled waste of stone materials derived from the process could reach 43% in the functional composite stone materials, that is the extreme of the refined batching of 3/4” coarse aggregate. However, the engineering quality of granite is slightly compromised since the homogeneity of the crystal of granite is worse than that of the silicon sand. Nonetheless, overall study results have shown that the recycled stone materials are justified as feasible functional composite stone materials.
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