碾压混凝土穿透型诱导缝等效强度和断裂试验研究

对碾压混凝土坝诱导缝强度和断裂特性进行了试验研究。在碾压混凝土长方体试件内埋设了削弱度为0 208～0 340的穿透型诱导缝,通过轴拉试验获得了诱导缝的等效强度和断裂韧度。分析表明:诱导缝强度的降低比例均大于诱导缝所在断面面积降低的比例,并且随着削弱的增大,诱导缝强度降低比例增长越快。最后分析了应力集中对等效强度的影响,削弱度在0～1之间,等效强度随削弱度的变化曲线为一条凹曲线,存在一个最佳削弱度,使得等效强度与削弱后剩余本体强度值的差值最大,此时,诱导缝发挥最佳的削弱断面强度作用。

Experimental study on fracture parameter and equivalent strength of penetrated induced joints in RCC

The strength of induced joint in RCC and its fracture characteristics are studied experimentally in laboratory.Penetrated induced joints with weakened variant ranging from 0.208 to 0.340 are placed into the rectangular specimens and the equivalent strength and fracture toughness of the joints are obtained by axial tension test.The analysis on experimental data shows that the percentage of joint strength reduction is larger than that of sectional area reduction and it tends to accelerate if the weakened variant reduces quickly.The influence of stress concentration on equivalent strength is also studied.It is found that an optimal weakened variant is existed for which the difference between equivalent strength and remained strength of the specimen after weakened is maximal when weaken variant ranging from 0 to 1.It means that at this point the effect of induced joints will be the most in reducing the sectional strength.