Han Yanqun, Meng Xiandong, Feng Fan, Song Xuming, Huang Fanglin, Wen Weibin
School of Civil Engineering, Central South University, Changsha 410075, China.
School of Architectural Engineering, Hunan Institute of Engineering, Xiangtan 411104, China.
Materials (Basel). 2023 Mar 27;16(7):2653. doi: 10.3390/ma16072653.
Modified polyurethane concrete (MPUC) is a new material for steel deck pavements. In service, the pavement is often cracked due to excessive tensile stress caused by temperature changes. In order to study the tensile properties of MPUC in the diurnal temperature range of steel decks, uniaxial tensile tests of MPUC were carried out at five temperatures. Three kinds of specimens and a novel fixture were designed and fabricated to compare the results of four different tensile test methods. The deformation of the specimen was collected synchronously by two methods: pasting strain gauge and digital image correlation (DIC) technique. Based on the experiment, the tensile mechanical properties, failure modes, and constitutive relations of MPUC were studied under the effect of temperature. The research results show that the novel fixture can avoid stress concentration. By observing the fracture surface of the specimens, the bonding performance is great between the binder and the aggregate at different temperatures. The tensile strength and elastic modulus of MPUC decrease with increasing temperatures, while the fracture strain, and fracture energy increase with increasing temperatures. The formulas of temperature-dependent tensile strength, fracture strain, and elastic modulus of MPUC were established, and the constitutive relationship of MPUC is further constructed in the rising stage under uniaxial tension. The calculation results show good agreement with experimental ones.
改性聚氨酯混凝土（MPUC）是一种用于钢桥面铺装的新型材料。在使用过程中，由于温度变化引起的过大拉应力，路面经常出现裂缝。为了研究MPUC在钢桥面昼夜温度范围内的拉伸性能，在五个温度下对MPUC进行了单轴拉伸试验。设计并制作了三种试件和一种新型夹具，以比较四种不同拉伸试验方法的结果。采用粘贴应变片和数字图像相关（DIC）技术两种方法同步采集试件的变形。基于试验，研究了温度作用下MPUC的拉伸力学性能、破坏模式和本构关系。研究结果表明，新型夹具可以避免应力集中。通过观察试件的断口表面，不同温度下粘结剂与集料之间的粘结性能良好。MPUC的抗拉强度和弹性模量随温度升高而降低，而断裂应变和断裂能随温度升高而增加。建立了MPUC随温度变化的抗拉强度、断裂应变和弹性模量公式，并进一步构建了单轴拉伸上升阶段MPUC的本构关系。计算结果与试验结果吻合良好。
