【摘要】 现有碳纤维加固预应力钢筒混凝土管(PCCP)技术不能有效发挥碳纤维的作用,也无法有效地抑制PCCP的变形和裂缝的扩展。为此,提出了PCCP内壁复式碳纤维加固技术,即在碳纤维与PCCP之间增设高压缩弹性垫层,研制出具有压缩量大、本体强度高、抗渗、与混凝土粘接强度大等特点的高压缩弹性垫层材料。根据弹性力学推导出内壁复式碳纤维加固PCCP的弹性解,并分别计算了在不同内水压力作用下对三种直径PCCP的应力分布情况。结果表明,当弹性垫层厚度为5 mm时,碳纤维的应力增加4.2~4.6倍,即增设弹性垫层后碳纤维加固PCCP的作用显著增加,作用于PCCP的内压明显减少;对于同一管径的PCCP,在固定内水压力下,随着高压缩弹性垫层厚度的增加,碳纤维的应力近似呈线性提高,碳纤维承担内水压力的比例也近似呈线性提高。更多还原

【Abstract】 The existing technology of carbon fiber reinforced polymer( CFRP) strengthened pre-stressed concrete cylinder pipe(PCCP) can neither effectively play the role of carbon fiber,nor effectively restrain the deformation and crack propagation of PCCP. Therefore,a technology of strengthening the inner wall of PCCP with composite CFRP is put forward herein,i. e. adding a high compressible and elastic cushion between CFRP and PCCP,for which the material for the high compressible and elastic cushion with the characteristics of large compressibility,high self-strength,impermeability and high bonding strength to concrete is developed. Based on elastic mechanics,the elastic solution for strengthening PCCP with CFRP is deduced,and then the stress distributions of PCCPs with three diameters under different internal water pressures are respectively calculated. The result shows that the stress of CFRP is to be increased by 4. 2 ~ 4. 6 times when the thickness of the elastic cushion is 5 mm,that is to say,the effect of strengthening PCCP with CFRP is significantly enhanced with obvious decrease of the internal pressure of PCCP after adding the elastic cushion. For the PCCPs with the same diameters,the stress of CFRP is approximately and linearly increased along with the increase of the thickness of the high compressible and elastic cushion,while the proportion of the internal water pressure borne by it is approximately and linearly increased as well.更多还原