| Summary: | 碩士 === 國立高雄應用科技大學 === 土木工程與防災科技研究所 === 94 === Among high tech products, liquid crystal glasses have been rapidly growing in recent years. Huge amount of industrial waste have produced during its process of manufacture. The objective of this research is to analyze the effect of replacing part of cement (or sand) by wasted liquid crystal glasses powder (or natural fine aggregate) to recycle the source. Three different water-to-binder ratios (0.4, 0.485, 0.6) were respectively mixed by 10, 20, 30, 40 and 50% wasted liquid crystal glasses powder which were added to replace part of cement in order to produce mortar specimen. Other concrete specimen whose has design compressive strength of 210, 280 and 350 kg/cm2 were added by 0, 20, 40, 60 and 80% wasted liquid crystal glasses powder in order to study the hardening, durability and volume stability characters of the fresh concrete.
Results show that setting time and hardening character of the mortar decreases as the amount of cement replaced by wasted liquid crystal glasses increases. Mixture of 10% replacement process the best quality because their physical properties, such as compressive strength (94~99%), bending strength (96~99%) and tensile strength (92~99%), are the most closest to the control specimen. In addition, the salt, sour and akali resistance capacity are also better than those from other proportion mixtures. Loss of weight is closer to or even better than the control group.
The slumps of concrete mixture in which 20% natural river sand were replaced by wasted liquid crystal powder maintain within the design range (15 ± 1㎝). Its hardening character is also the best among all the proportion mixtures. As compared to the control group, the compressive strength is 93～98％, bending strength 95～98％ and split strength 97～99％ for 28 day specimen. Compressive, bending and split strength is 98.5～99.5, 96～99, and 97～105％ respectively for longer curing (56 to 90 days) specimen. Concrete in which 20, and 30% natural river sand were replaced by wasted liquid crystal powder process similar bond strength for steel reinforcement as the control group. For all the proportion mixtures, the Young’s modulus, ranged between 20~40 Gpa and higher than 15080 , are higher than the control group. The resistance to sulfates for specimen of 20% replacement is below 0.7% which is more stable. Electric resistance properties are similar between control and 20% replacement specimen whose fc’=210、280、350 kg/cm2. For long period electric resistance（12.25、10.45、12.0 KΩ-㎝）, they were larger than the control group. Ultrasonic pulse velocity for 28-day specimen is ranged from 4100 to 4400 m/sec which is good. Speed for longer curing, fc’= 350 kg/cm2, 20, 40, and 60% replacement specimen are over 4500 m/sec which were excellent concrete property. It can be concluded that to mix wasted liquid crystal glasses powder to concrete not only reduce the amount of using natural sand, but also provide protection to our environment. It is economy and safe in applications.
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