| 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 === 96 === This study is focused on the investigation of how a new copolymer chemical admixture affects the engineering properties of concrete.This research adopts two mixture designs (ACI mixture design algorithm and Densities mixture design algorithm). We fix the PD dosage and change the water-to-binder ratio (W/B = 0.30, 0.36, 0.42) to mix concrete, and use the cement paste and mortar to figure out how the Copolymer Chemical Admixture affects the cement beforehand.The tested items include fresh concrete (slump, slump flow, slump loss, setting time, air contain and unit weight) and hardened concrete (compressive strength, ultrasonic pulse velocity, electrical resistance, length change and SEM microstructure observation).Its result shows that because the PD has positive and negative ion and can adsorb on the cement particle to disperse, so we can reduce the water-to-cement ratio and extend the setting time by water reduction. The compressive strength, ultrasonic pulse velocity and rebound hammer number also increase 25%. In ACI mixture design algorithm, the water-reducing ratio exceeds the 12% which specified in CNS standard. It means the PD belongs to Water-reducing high range admixtures and has 1.5 ~ 3 hours set-retarding compared to control concrete.In Densities mixture design algorithm, the comparison of three kinds of PD and SPF, the slump loss of PD is smaller, setting time is longer, ultrasonic pulse velocity and resistance value slightly less than SPF. The entire performance of PD is between Type F and Type G in CNS 12283.
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