一种适合混凝土水下修复的新型环氧砂浆

水工混凝土建筑物由于运行环境的复杂性,普遍存在水下开裂破损等病险。为不影响建筑物运行,尽可能选择在水下修复,其关键是选择适宜的修复材料。为此研发了一种适合水下混凝土修复的新型环氧砂浆,并通过试验研究了其主要力学性能及主要影响因素。试验结果表明:新型环氧砂浆3 d无侧限抗压强度达到60 MPa以上;当胶固比为1∶2.5时,水下浇筑的环氧砂浆黏接强度最大,超过了3.0 MPa;当胶固比为1∶3.5时,环氧砂浆的抗冲磨强度(水下钢球法)最大,达到847.800 h/(kg/m²)。性能测试及实际工程应用表明:新型环氧砂浆具有抗压强度高、水下黏接(与混凝土)强度大、抗冲磨效果好等特点,能够与旧混凝土协调工作。在具体工程中,可根据不同的病险类型,选择适宜的胶固比及有关施工参数。

A Novel Epoxy Mortar for Underwater Repair of Concrete

Due to the complexity of environment, hydraulic concrete buildings are generally subject to underwater cracking damage and other hazards. The key to underwater repair of such hazards, which could keep the hydraulic structures from disturbance, is to select appropriate repair materials. To this end, a novel type of epoxy mortar suitable for underwater concrete repair is developed, and the main mechanical properties and main influencing factors are studied via experiment. Results demonstrate that the 3-day compressive strength of the proposed epoxy mortar is over 60 MPa. When the ratio of glue to solid is 1∶2.5, the bonding strength of underwater-poured epoxy mortar reaches the maximum, more than 3.0 MPa; when the glue-solid ratio is 1∶3.5, the epoxy mortar’s anti-abrasion strength (obtained by underwater steel ball method) amounts to 847.8 h/(kg/m²), which is the maximum. Performance test together with practical engineering application proves that the proposed epoxy mortar is of high compressive strength, large underwater bonding (with cement mortar) strength and good anti-abrasion effect, and is able to work with old concrete. In specific engineering, appropriate glue-solid ratio and related construction parameters should be selected carefully depending on different types of hazards.