高温喷水冷却后再生卵石混凝土应力-应变本构关系及有限元分析

Stress-strain Constitutive Relation and Finite Element Analysis of RecycledPebble Concrete After High Temperature Water Cooling

为研究高温喷水冷却后再生混凝土(卵石类)的力学性能,以温度和取代率为变化参数设计并制作了60个标准圆柱体试块,并对其进行了单轴受压试验。观察了试块的破坏形态,获取了全过程荷载-位移曲线,提出了适用于ABAQUS有限元分析的高温喷水冷却后再生混凝土本构方程,并基于前期试验验证了该本构关系。研究表明:高温喷水冷却后再生卵石混凝土在较高温度作用后出现酥松和爆裂的现象;烧失率在温度较低时出现正增长;高温喷水冷却后全再生混凝土在轴压试验中产生更多细小的裂纹,再生混凝土比普通混凝土有着更低的峰值应力和峰值应变,但有着更好的延性;所提出的高温喷水冷却后再生混凝土剩余承载力计算方法有一定适用性;基于前期22根高温喷水冷却后再生混凝土梁试验,考虑温度和取代率提出的本构方程在ABAQUS中有较好的适用性。

In order to study the mechanical properties of recycled concrete(pebbles)after high-temperature water cooling,60 standard cylinder test blocks were designed and manufactured with temperature and replacement rate as variable parameters,and uniaxial compression tests were carried out on them.The failure mode of the test block was observed,the load displacement curve of the whole process was obtained,and the constitutive equation of recycled concrete after high temperature water cooling was put forward,which was suitable for the finite element analysis of ABAQUS.The results show that:the recycled pebble concrete appears the phenomenon of looseness and bursting after high-temperature water cooling,and the burning loss rate increases positively at low temperature.The recycled concrete has lower peak stress and strain,but has better ductility than ordinary concrete.The proposed calculation method of RAC residual bearing capacity after high temperature spray cooling has certain applicability.Based on the experiment of 22 recycled concrete beams after high temperature water cooling,the constitutive equation considering temperature and substitution rate is applicable in ABAQUS.