Trapko Tomasz, Musiał Michał
Faculty of Civil Engineering, Wroclaw University of Science and Technology, Pl. Grunwaldzki 11, 50-377 Wroclaw, Poland.
Materials (Basel). 2020 Mar 9;13(5):1221. doi: 10.3390/ma13051221.
This paper examines the effect of PBO (P-phenylene benzobisoxazole)-FRCM (Fabric Reinforced Cementitious Matrix) reinforcement on the stiffness of eccentrically compressed reinforced concrete columns. Reinforcement with FRCM consists of bonding composite meshes to the concrete substrate by means of mineral mortar. Longitudinal and/or transverse reinforcements made of PBO (P-phenylene benzobisoxazole) mesh were applied to the analyzed column specimens. When assessing the stiffness of the columns, the focus was on the effect of the composite reinforcement itself, the value and eccentricity of the longitudinal force and the decrease in the modulus of elasticity of the concrete with increasing stress intensity in the latter. Dependences between the change in the elasticity modulus of the concrete and the change in the stiffness of the tested specimens were examined. The relevant standards, providing methods of calculating the stiffness of composite columns, were used in the analysis. For columns, which were strengthened only transversely with PBO mesh, reinforcement increases their load capacity, and at the same time, the stiffness of the columns increases due to the confinement of the cross-section. The stiffness depends on the destruction of the concrete core inside its composite jacket. In the case of columns with transverse and longitudinal reinforcement, the presence of longitudinal reinforcement reduces longitudinal deformations. The columns failed at higher stiffness values in the whole range of the eccentricities.
本文研究了对亚苯基苯并双恶唑（PBO）-织物增强水泥基复合材料（FRCM）加固对偏心受压钢筋混凝土柱刚度的影响。FRCM加固是通过矿物砂浆将复合网粘结到混凝土基体上。由PBO（亚苯基苯并双恶唑）网制成的纵向和/或横向钢筋应用于分析的柱试件。在评估柱的刚度时，重点关注复合加固本身的影响、纵向力的值和偏心距以及随着混凝土应力强度增加其弹性模量的降低。研究了混凝土弹性模量的变化与测试试件刚度变化之间的关系。分析中使用了提供复合柱刚度计算方法的相关标准。对于仅用PBO网横向加固的柱，加固增加了它们的承载能力，同时，由于截面的约束，柱的刚度增加。刚度取决于其复合套内部混凝土芯的破坏。对于有横向和纵向钢筋的柱，纵向钢筋的存在减少了纵向变形。在整个偏心距范围内，柱在较高的刚度值时破坏。
