| Summary: | 碩士 === 逢甲大學 === 土木工程學系 === 103 === In recent years, more and more examples of lightweight aggregate used in building have emerged. The use of lightweight aggregate characteristics can improve performance of a building’s heat insulation, sound insulation, etc., and can reduce costs and energy consumption. However, among lightweight aggregate concrete, the strength of lightweight aggregate is lower in comparison with cement mortar. Therefore, the strength impact of lightweight aggregate on lightweight aggregate concrete should be taken into account with care.
This study uses a total of three types of expanded perlite, adopting “ACI 211.1” as the concrete mix design method of design strength 210kgf / cm2, making a lightweight cylindrical concrete test specimen with the same volume of perlite lightweight aggregate concrete alternative to fine aggregate in normal-weight concrete, and the test specimen shall be divided into experimental group associate Perlite B used in construction, perlite C used in insulating brick, perlite T used in insulating tube and the control group associate normal-weight concrete N at totaling five proportions of 20%, 40%, 60%, 80% and 100% alternatives to replace the fine aggregate volume and to make test specimen for measuring weight and compression tests. Finally, commencing the comparison to the extent and degree of light weighting concrete and extent of influence of the compression strength of concrete are compared.
The research conclusions show that under the condition of the same water-cement ratio, the expanded perlite lightweight aggregate concrete alternative to fine aggregate volume has a lower unit weight and can moderately reduce the weight of the concrete structure (0.88% ~16.2%), while the impacts on compression strength are mostly negative (-37.58% ~5.32%). Overall, comprehensively considering the degree of concrete light weighting and compression strength, the perlite used in construction is the most appropriate alternative to fine aggregate in the concrete among the three lightweight aggregates in this study. When the replacement rate of fine aggregate volume reaches 100%, the unit weight of concrete is 16.2% lower than the test specimen completely made of natural sand, and the compression strength decreases by 26.62%. Followed by the perlite used in insulation brick, and the last is the perlite used in insulating tube.
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