Establishing the Correlation between the Pulse Velocity and Concrete Strength Using the Coarse Aggregate Content as Key Parameter

• Main Authors: Kuo-Fong Kao, 高國峰
• Other Authors: Yi-Ching Lin
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/59894443918324478563

碩士 === 國立中興大學 === 土木工程學系 === 92 === The objective of the thesis is to study how the correlation between the pulse velocity and the concrete strength varies with concrete mixtures. The results obtained from many previous studies show that the change in concrete mixtures will result in significant variation of the correlation between the concrete strength and the pulse velocity. If all the experimental data are put together in a graph for concrete with various mixtures, a certain pulse velocity will be associated with many corresponding strength values. This hinders the use of the pulse velocity for evaluating concrete strength. There is a need to find out how the correlation between the pulse velocity and the concrete strength varies with concrete mixtures. In this thesis, the variables in concrete mixtures include the amount of coarse aggregate(1170, 1040, 910, 780 kg/m3), paste volumes (33%, 36%) and water-cement ratios (0.7, 0.6, 0.5 and 0.4). There are 32 concrete mixtures. Twelve specimens are prepared for each concrete mixture. There are 384 (32*12=384) specimens to be cast altogether (mold size：Φ×h=0.10m×0.20m). Concrete cylinders are cured in water at 23°C and tested at 3, 7, 14 and 28 days. The experimental results show that the pulse velocity increases with the increase in the aggregate content. On the other hand, the reduction in water-cement ratios enhances the pulse velocity of concrete. The strength of ordinary concrete is mainly controlled by the water-cement ratios. However, the pulse velocity is influenced significantly by the coarse aggregate content. It is found that the coarse aggregate content and the water-cement ratios can serve as media to establish a better relationship between the pulse velocity and concrete strength.