高强化再生混合混凝土的基本徐变试验研究

Test on basic creep behaviors of compound concrete made of normal-strength demolished concrete lumps and high-strength fresh concrete

通过对3组高强化再生混合混凝土圆柱体试件(由C70新混凝土和C30废旧混凝土块体混合浇筑而成)、1组C70新混凝土圆柱体试件、1组C30废旧混凝土圆柱体试件的基本徐变试验,分析了废旧混凝土块体取代率和应力比对高强化再生混合混凝土徐变性能的影响。研究表明:高强化再生混合混凝土的徐变度和徐变柔量均随着废旧混凝土块体取代率的增加有所增大,总体上小于废旧混凝土的徐变度和徐变柔量,而与新混凝土的徐变度和徐变柔量相对更为接近;当应力比小于0.4时,高强化再生混合混凝土的基本徐变仍近似与其应力比成正比。

Experimental study on basic creep behaviors of three groups of cylindrical specimens made of C30 normal-strength demolished concrete lumps (DCLs) and C70 high-strength fresh concrete (FC), one group of cylindrical specimens made of the C70 FC alone, and one group of cylindrical specimens drilled from the C30 waste concrete has been conducted. Influences of the stress level and the replacement ratio of DCLs on the specimens' basic creep have been discussed. It is found that: both the specific creep and the creep function of the compound concrete made of normal-strength DCLs and high-strength FC are remarkably less than those of the demolished concrete and relatively close to those of the FC, and increase with the increasing of the replacement ratio of DCLs; when the stress level is lower than 0.4, the basic creep of the compound concrete made of normal-strength DCLs and high-strength FC is still approximately proportional to the stress level. © 2016, Editorial Office of Journal of Building Structures. All right reserved.