超高性能纤维混凝土力学性能综述

Study on Mechanical Properties of Ultra-high-performance Fiber-reinforced Concrete

为使超高性能纤维混凝土(UHPFRC)更好地应用于实际施工,对各种影响因素(包括养护条件、粗骨料、矿物掺合料,纤维方向,尺寸效应)对硬化UHPFRC的基本力学性能进行了论述。研究结果显示:热处理可以产生超高抗压强度。用粉煤灰或矿渣代替硅粉对UHPFRC抗压强度没有明显影响,但对其抗弯强度和韧性影响显著。端部浇筑混凝土的梁最大荷载比中部浇筑混凝土的梁高出约15%。大尺寸的UHPFRC比小尺寸的UHPFRC力学强度低,且尺寸效应对弯曲强度比轴向强度影响大得多。

In order to make ultra-high-performance fiber-reinforced concrete(UHPFRC)better applied in the construction,the basic mechanical properties of hardened UHPFRC were studied according to various factors(curing conditions,coarse aggregate,mineral admixtures,fiber orientation,and size effect).The results show that heat treatment can produce super high compressive strength.The replacement of silica fume with fly ash or slag has no significant effect on the compressive strength of UHPFRC,but has a significant effect on its flexural strength and toughness.The maximum load of the beam with concrete poured at the end is about 15%higher than that of the beam with concrete poured at the middle.The mechanical strength of UHPFRC with large size is lower than that of UHPFRC with small size,and the size effect on bending strength is much greater than that on axial strength.