冻融循环下高强灌浆料的力学性能分析

Analysis of mechanical properties of high-strength grouting material under freeze-thaw cycles

考虑了冻融循环对高性能水泥基材料高强灌浆料力学性能的影响,通过对比国内外规范设计了不同尺寸试块的冻融循环试验,均得到了其轴压强度随冻融循环次数的增加呈先基本保持不变后加速下降的趋势,并分析得到了高强灌浆料轴压作用下的有效冻融次数为200~250次;然后对试验结果进行了归一化处理,得到了高强灌浆料相对强度与冻融循环次数的变化规律,并给出了关系式;最后将试验得到的高强灌浆料应力应变关系曲线进行了线性处理,导入了Comsol有限元软件,通过三场耦合对高强灌浆料的冻融循环过程进行了数值模拟,得到了各观测点的应力增减情况,说明温度循环作用下产生的应力会随冻融循环次数的增加不断积累,特别是在达到200次冻融循环时,应力增幅突然变大,增幅约为23.98%,也从侧面说明了高强灌浆料所能经历的冻融循环次数在200次以内时可保证其强度可靠性。

Considering the influence of freeze-thaw cycles on the mechanical properties of high-strength grouting material of high-strength cement-based materials,by comparing domestic and foreign specifications and designing the freeze-thaw cycle tests of different sizes of test blocks,the trend that the axial compressive strength will remain unchanged and then fall deeply with the increase of the number of freeze-thaw cycles have obtained.The effective freeze-thaw cycles under the axial compression of high-strength grouting are 200~250 times.The experiment results are normalized to obtain the change law of the relative strength of high-strength grouting material and the increase of the number of freeze-thaw cycles,and the relationship was given.Finally,the stress-strain relationship curve of the high-strength grouting material obtained by the experiment is linearly processed and then imported into Comsol.The three-field coupling method is used to simulate the freeze-thaw cycle of high-strength grouting material,and the stress increase and decrease of each observation point is obtained.It shows that the stress generated by the temperature cycle will accumulate with the increase of the number of freeze-thaw cycles,especially when the temperature cycles reach 200 times,the stress increase suddenly increases,and the growth is about 23.98%.It also shows from the side that the high-strength grouting material can guarantee the strength and reliability of the freezing and thawing cycles that can be experienced within 200 times.