Mesoscopic simulation of crack propagation and bond behavior in ASR damaged concrete with internal/external restraint by 3D RBSM
Mesoscopic simulation of crack propagation and bond behavior in ASR damaged concrete with internal/external restraint by 3D RBSM
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DOI：
10.1016/j.cemconcomp.2022.104488
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发表时间：
2022-03-16
影响因子：
10.5
通讯作者：
Nagai, Kohei
中科院分区：
文献类型：
--
作者：
Luo, Jie;Wang, Yi;Nagai, Kohei
碱-硅反应（ASR）引起的钢筋混凝土（RC）结构的膨胀和开裂是RC结构最严重的使用性能问题之一，它对材料性能以及钢筋与周围混凝土之间的粘结有负面影响。在一个典型的钢筋混凝土构件中，ASR引起的混凝土膨胀和开裂受到内部钢筋以及边界条件的限制。由于损伤机理复杂，难以通过试验研究来理解，因此预测受损钢筋混凝土结构的剩余承载力并不容易。在这项研究中，作者使用了一个三维刚体弹簧模型（RBSM），包括砂浆，骨料和钢元素，能够模拟ASR在钢筋混凝土中的膨胀。为了研究多个参数之间的复杂相互作用并量化ASR损伤对结构性能的影响，对先前报道的ASR引起的内部和外部约束下的膨胀实验进行了模拟，沿着ASR膨胀后的拔出行为实验。在每种情况下，宏观ASR膨胀的约束效果是很好的建模，以及如何发展的内部应力和混凝土开裂的约束的影响，可以解释从模拟。模拟能够讨论ASR引起的裂纹的数量和在各种情况下的内部应力条件。对不同ASR损伤程度的混凝土的峰值粘结强度进行了准确的预测，并对ASR损伤混凝土的荷载-位移曲线进行了讨论。
One of the most serious serviceability concerns for reinforced concrete (RC) structures is expansion and cracking resulting from the alkali-silica reaction (ASR), which has a negative effect on material properties as well as the bond between reinforcement and surrounding concrete. In a typical RC member, ASR induced concrete expansion and cracking are restrained by internal reinforcement as well as the boundary conditions. The mechanism is complex and difficult to understand through experimental study, so predicting the residual capacity of a damaged RC structure is not easy. In this study, the authors use a 3D Rigid Body Spring Model (RBSM) comprising mortar, aggregate and steel elements and which is able to simulate ASR expansion in reinforced concrete. To study the complex interactions among multiple parameters and quantify the effect of ASR damage on structural behavior, previously reported experiments on ASR induced expansion under internal and external restraint are simulated, along with experiments on pullout behavior after ASR expansion. The effect of restraints on macroscopic ASR expansion is well modeled in each case, and how the development of internal stresses and concrete cracking influenced by the restraint can be explained from the simulations. The simulations enable discussion of the number of ASR-induced cracks and the internal stress condition in various cases. The peak bond strength of concrete with different ASR damage levels, as reported in pullout experiments, is predicted accurately and the load-displacement curves of ASR damaged concrete are discussed.