Hwang Euichul, Kim Gyuyong, Koo Kyungmo, Moon Hyungjae, Choe Gyeongcheol, Suh Dongkyun, Nam Jeongsoo
Department of Architectural Engineering, Chungnam National University, 99 Daehak-ro, Daejeon 34134, Korea.
Building Engineering Team, Hanwha Engineering & Construction, 86 Cheonggyecheon-ro, Seoul 04541, Korea.
Materials (Basel). 2021 Sep 2;14(17):5026. doi: 10.3390/ma14175026.
Concrete undergoes shrinkage regardless of the influence of external forces. The deformation of concrete is crucial for the structural stability of high-rise and large-scale buildings. In this study, the shrinkage and compressive creep of 70-90 MPa high-strength concrete used in high-rise buildings were evaluated based on the curing conditions (sealed/unsealed), and the existing prediction models were examined. It was observed that the curing condition does not significantly affect the mechanical properties of high-strength concrete, but the use of limestone coarse aggregate increases the elastic modulus when compared to granite coarse aggregate. The autogenous shrinkage of high-strength concrete is greater than that of normal-strength concrete owing to self-desiccation, resulting in a large variation from the value predicted by the model. The drying shrinkage was observed to be similar to that predicted by the model. Compressive creep was affected by the curing conditions, compressive strength, loading level, and loading age. The compressive creep of high-strength concrete varied significantly from the prediction results of ACI 209; ACI 209 was modified based on the measured values. The shrinkage and compressive creep characteristics of high-strength concrete must be reflected to predict the deformation of an actual structure exposed to various conditions.
无论外力影响如何，混凝土都会发生收缩。混凝土的变形对于高层和大型建筑的结构稳定性至关重要。在本研究中，基于养护条件（密封/未密封）评估了高层建筑中使用的70 - 90MPa高强度混凝土的收缩和压缩徐变，并检验了现有的预测模型。观察到养护条件对高强度混凝土的力学性能影响不显著，但与花岗岩粗骨料相比，使用石灰石粗骨料会提高弹性模量。由于自干燥，高强度混凝土的自收缩大于普通强度混凝土，导致与模型预测值有较大差异。观察到干燥收缩与模型预测值相似。压缩徐变受养护条件、抗压强度、加载水平和加载龄期的影响。高强度混凝土的压缩徐变与美国混凝土学会（ACI）209的预测结果有显著差异；基于测量值对ACI 209进行了修正。必须反映高强度混凝土的收缩和压缩徐变特性，以预测实际结构在各种条件下的变形。
