Study on Characteristics of Coarse Aggregate in High Performance Concrete

• Main Authors: Fu-Chang Chung, 莊福昌
• Other Authors: Ta-Peng Chang
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/67276031788083858310

碩士 === 國立臺灣科技大學 === 營建工程技術學系 === 83 === This study bases on the proportional method of th least-void ratio concept to mix the high-performance concrete. The effects of coarse aggregate properties from four defferent kinds on the strengths of concrete at various ages are investigated. Under same proportion, the relations between different aggregates, aggregate gradings, aggregate sizes and uniaxial compressive strength of concrete specimens are presented. The influence of the basic characteristics for different aggregates on the stress-strain curve, elastic modulus, flexural strength and splitting tensile strength of concrete specimens are discussed. The bonding state between mortar and different aggregates, and the surface condition of aggregates are also examined by SEM. Experimental results indicate that the compressive strengths of types A, B, C, and D aggregates are 93.55, 71.68, 69.96 and 42.37 Mpa respectively; the splitting tensile strengths are 3.72, 3.36, 2.72 and 2.21 Mpa respectively; the elastic moduli are in the range of 15.96 to 23.55 GPa respectively. Under the condition of same aggregate but having uniform aggregate sizes, aggregates with the higher strength do not mecessarily have a higher compressive strength of the corresponding concrete specimens. Same aggregates but with different grading have little effects on the elastic modulus of concrete. Aggregates with better engineering properties always have denser interior constitution, better workability and higher pulse speed of sound.