Study on Engineering Properties of Hydraulic Concrete with Green Design
| Autor: | Chih-yen Lin, 林志彥 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 This research mainly focuses on the investigation of engineering properties and abrasion resistance capability for the hydraulic concrete with green design. Experimental variables include the water-to-binder ratios (W/B = 0.3、0.4、0.5), the percentage of sand (S/A = 40%、50%、60%), amount of silica fume (SF = 0%、5%、10%), and amount of polypropylene fiber (PP = 0%、0.1%、0.2%). The Taguchi method for mix proportion together with the statistical methods of ANOVA and signal-to-noise (S/N) ratio were used to understand the influence of each factor on the response. Afterward, at a fixed water-cement ratio, variations of the percentage of sand, amounts of silica fume and fiber were used as the factors to study the correlation among the engineering properties and abrasion resistance capability. The results of study shows that：(1) From the Taguchi experimental method, the water-cement ratio and polypropylene fibers significantly affect the fresh property; for the properties of ultrasonic pulse velocity, dynamic of elastic modulus, dynamic of shear modulus, compressive strength and splitting tension strength, the water-binder ratio is the maximum impact factor and has the greatest contribution; at the age of 56 days, the silica fume content is the main factor in the surface resistivity and chloride penetration test, followed by water-binder ratio; wet concrete specimens have higher values of ultrasonic pulse velocity, dynamic modulus of elasticity and dynamic shear modulus but lower values of compressive and splitting tensile strengths than those for dry concrete specimens; (2) From the evaluation on the criteria of material selection and amount of usage of mixture proportion with green design, it is found that all the mixtures in this study can reach the index requirement by 60~77%, and from the performance evaluation, most of the mixtures in this study can reach the index requirement by 49~83%. (3) The results from the full factorial experiment show that when the percentage of sand increases from 40 % to 60 %, regardless if the fiber is added or not, the slump flow tends to reduce and similar tendency of reduction in slump flow was observed when the silica fume and fiber were added to the mixture; the ultrasonic pulse velocity, dynamic of elastic modulus, dynamic of shear modulus, and compressive strength of concrete specimen are decreased with the increase of the percentage of sand, and increased with the increase of silica fume and fiber contents; the sand surface resistivity of concrete decreases with the increase of the percentage of sand by 0.44 ~ 14.79 %, increases with the increased silica fume content by5.98 ~ 73.68%, and increases by 0.26~19.32% with the increase of added fiber content; the abrasion resistance capability of wet and dry concrete specimens increases with the increase of percentage of sand, added silica fume and fiber contents. (4) When the ultrasonic pulse velocity higher than about 4600 m/s, dynamic modulus of elasticity higher than about 36 GPa, shear modulus higher than about 13.5 GPa, compressive strength higher than about 45 MPa and modulus of rupture higher than 6.2 MPa, the abrasion percentage of concrete specimens keeps at the values between 3.1 ~ 3.5%.concrete Concrete abrasion loss rate is decreases when the ultrasonic pulse velocity, dynamic of elastic modulus, dynamic of shear modulus, compressive strength and bending strength increases. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|