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本文系统地研究了一系列强度等级的无约束和箍筋约束泵送卵石和碎石高性能及超高性能混凝土的多种基本力学性能,包括立方体强度、轴压强度、弹性模量、峰值应变等。并与国内外大量的相关试验结果进行了比较。试验与分析表明:卵石与碎石高性能混凝土的基本力学性能基本相同,对于无约束高性能混凝土,轴压强度与立方体抗压强度的比值、峰值应变以及弹性模量均高于普通混凝土,峰值应变和弹性模量随着混凝土强度的提高而提高;高性能混凝土的应力-应变关系在峰值应力之前接近于直线,塑性变形很小;峰值应力后,高性能混凝土应力-应变关系的下降段很陡,表现出较大的脆性。对于箍筋约束混凝土,其强度和峰值应变均有较大的提高,分别提高20%～35%和32%～66%;其应力-应变曲线下降平缓,表现了较好的延性。与其他文献结果对比表明,本文高性能混凝土延性较好,弹性模量较低。
This paper systematically studied a series of strength grades of unconstrained and stirrup constrained pumped pebbles and gravel for high performance and ultra-high performance concrete for a variety of basic mechanical properties, including cube strength, axial compressive strength, elastic modulus, and peak strain. Wait. And compared with a large number of relevant test results at home and abroad. Tests and analysis show that the basic mechanical properties of pebbles and crushed stone high performance concrete are basically the same. For unconstrained high performance concrete, the ratios of axial compressive strength to cubic compressive strength, peak strain and elastic modulus are all higher than those of ordinary concrete. The strain and elastic modulus increase with the increase of concrete strength; the stress-strain relationship of high-performance concrete is close to a straight line before the peak stress, and the plastic deformation is very small; after the peak stress, the drop of the stress-strain relationship of high-performance concrete is very high. Steep, showing greater brittleness. For the confined concrete with stirrups, its strength and peak strain have been greatly improved by 20% to 35% and 32% to 66%, respectively; the stress-strain curve has decreased smoothly, showing a good ductility. Comparison with other literatures shows that high performance concrete has better ductility and lower elastic modulus.