Mechanical Properties of High-Strength-Fly Ash Lightweight ete

• Main Authors: Yu-Feng Wang, 王玉鳳
• Other Authors: Ta-Peng Chang
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/30838104424054624553

碩士 === 國立臺灣科技大學 === 營建工程技術學系 === 81 === This study, based on the "least-void-ratio" concept of concrete proportional method, presents the experimental results the properties of high-strength concrete with cold-pelletized lightweight fly-ash aggregates. The experimental variables, are selected to investigate their effects on the compressive strength, unit weight and etc., include substitution of cement silica fume, addition of steel fiber, water-cement ratio and of mortar. In addition, the splitting test, flexural test and fracture test were also conducted for the proportional ratio of high-strength light weight concrete which gives the highest compressive strength. The fracture test contains the fracture toughness, stress intensity factor, load-deflection curve and CMOD (Crack Mouth Opening Displacement) curve. It is shown that the substitution of cement with silica fume increases the compressive strength, but adversely decrease the values of splitting strength, flexural strength and fracture toughness. On the other hand, the addition of steel fiber does not alter a negligible variation of the compressive strength, but obviously improves the splitting strength, flexural strength and toughness. On fracture properties, the high-strength lightweight cold- pelletized fly-ash aggregate concrete shows an apparent tendency size effects, from which the fracture toughness ranged from 34 to 52 N/m and stress intensity factor ranged from 949000 to 1120000 N/m1.5 were calculated. Those values of stress intensity factor found to be comparative to those of normal concretes.