低水泥量高性能混凝土之力學性質研究

Abstract

本文研究低水泥量高性能混凝土(LcHPC)之力學性質，探討其強度成 長、水泥量影響、應力-應變行為、彈性模數及柏松比。 結果顯示， 採用低水泥量、添加波索蘭材料及提高粗骨材含量(達0.45m^3/m^3)的方 式，可以降低水化熱、減少微裂縫量和增加晚期強度與彈性糢數，且90天 強度可達75MPa以上，改善一般高水泥量高性能混凝土之缺點。 關於 彈性模數方面，以目前規範所建議的經驗式預估國內高性能混凝土時，發 現有高估的現象。本文以迴歸試驗資料所得之預測式預估彈性模數值，經 與其他HPC資料比較後評估出，預測值可以得到很好的近似結果。

This study presents the mechanical properties of low cement high-performance concrete(LcHPC). Discussions focus on compressive strengthgain with time, stress-strain behavior in uniaxial compression, modulusof elasticity, and Poisson''s ratio. The test results show that by incorporating low quantity of cementand high volumes of mineral admixtures and coarse aggregates(0.45m^3/m^3),LcHPC can decrease heat of hydration and thermal microcracking, and increasecompressive strength and modulus of elasticity at later ages. Also, the compressive strength can reach over 75MPa. LcHPC improve the disadvantage of common high-performance concrete with high cement contents. As regarding modulus of elasticity, it was observed that the existing empirical formulas of some codes overestimated the modulus of elasticityfor domestic HPC. In this study, the predicated expression obtained byregressing the experimental data estimated elastic modulus, and then compared with other test results of HPC, it was found the predicted valuesgot a reasonable approximation.