短龄期新老混凝土粘结强度等效系数

试验采用3种粘结剂对3种混凝土进行粘结,以劈拉强度作为评价指标,将这3种粘结剂对混凝土的粘结效果进行对比,旨在找出3种混凝土中最适宜使用粘结剂的混凝土。另外首次提出了新老混凝土粘结强度新的评价指标——粘结强度等效系数β(某种混凝土粘结劈拉强度与同种混凝土基准试件劈拉强度的比值),并以β值作为指标对这3种混凝土进行对比。通过对粘结强度等效系数的对比可得3种界面粘结剂用于普通硅酸盐水泥配制的混凝土的粘结效果均优于其它2种水泥配制的混凝土的粘结效果,普通硅酸盐水泥配制的混凝土在新老混凝土粘结试验中对界面粘结剂的适用性最强,其28 d的粘结强度最大值可以达到混凝土基准试件劈拉强度的0.86,粘结效果最佳。

Equivalent Coefficient of Short Age Strength of BondingBetween New and Old Concrete

In the purpose of selecting a concrete most suitable for bonding, three kinds of concrete (ordinary Portland cement, slag cement, and composite Portland cement) were bonded by three binders respectively, and the bonding effect were compared with split tensile strength as the evaluation indicator.Furthermore, the equivalent coefficient β of bonding strength, which is an index of evaluation the strength of bonding between new and old concrete, is proposed for the first time.It is the ratio of splitting tensile strength of a bonded concrete to splitting tensile strength of standard specimen of the concrete.Comparison of β among the three concretes revealed that the bonding effect of three binders on ordinary Portland cement is better than that of the other two, with the 28 d bonding strength reaching 86% of the tensile strength of standard specimen, which suggest that ordinary Portland cement is the most suitable for bonding among the three concretes.