Effect of double-layer formwork curing on the early temperature field and properties of precast concrete components in environments with large diurnal temperature variations  

作　　者：Yue Tong Weikang Kong Zhihong Duan Lei Ma Rongxin Guo Ya Wei 

机构地区：[1]Yunnan Xuanhui Expressway Co.,Ltd.,Qujing 655000,China [2]Intelligent Transportation System Research Center,Southeast University,Nanjing 210096,China [3]Chengdu Xingcheng Investment Group Co.,Ltd.,Chengdu 610041,China [4]Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,Kunming 650500,China [5]Department of Civil Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Low-carbon Materials and Green Construction》2024年第1期189-208,共20页低碳材料与绿色建造(英文)

基　　金：support from the project of the Science and Technology Innovation Project of the Department of Transport of Yunnan Province(YJKJB[2023]150).

摘　　要：An efficient double-layer formwork curing method using an“inner supporting formwork+outer insulation formwork”was proposed in this study to address the early cracking of precast concrete components in high altitude regions.Steel and plywood formwork were designed as inner support formwork,while polystyrene(PS)and polyurethane(PU)were used as outer insulation formwork.Indoor experiments and two finite element methods(The complete simulation method focuses on computational accuracy,and the equivalent simulation method emphasizes computational efficiency)were employed to analyze the evolution of the concrete temperature field under different double-layer formwork curing methods throughout the curing period,combined with compressive strength and pore structures testing.The results show that steel+5-mm-thick PU insulation formwork curing method can significantly mitigate the impact of large diurnal temperature variations on the internal temperature of concrete.Unlike traditional steam-curing,this method does not deteriorate the pore structure or compressive strength of the concrete.This study is of great significance in addressing the problem of early cracking of precast concrete components exposed to large diurnal temperature vriations in high altitude regions.为了解决高海拔地区预制混凝土构件的早期开裂问题,本研究提出了一种“内支撑模板+外保温模板”的高效双层模板养护方法。选择钢模板和胶合板模板作为内支撑模板,聚苯乙烯(PS)和聚氨酯(PU)作为外保温模板。通过室内试验以及两种有限元方法(完全模拟法侧重于计算精度,等效模拟法强调计算效率),分析了在不同双层模板养护方法下混凝土温度场在整个养护期间的演变情况,亦包括了抗压强度和孔隙结构测试。结果表明,钢模板+5mm厚PU保温模板的养护方法能有效缓解较大昼夜温差对混凝土内部温度的影响。与传统的蒸汽养护不同,这种方法不会造成混凝土内部孔隙结构的恶化,也不会降低混凝土抗压强度。本研究对于解决高海拔地区昼夜温差大的环境下的混凝土预制构件早期开裂问题具有重要意义。

关 键 词：Double-layer formwork curing Large diurnal temperature variations POROSITY Thermal insulation curing Temperature field 

分 类 号：TU5[建筑科学—建筑技术科学]