火灾后混凝土结构的评估与维修

EVALUATION AND REPAIR OF CONCRETE STRUCTURES AFTER FIRE

本文详细介绍了火灾后混凝土结构的现场勘察、材料性能的检测方法。给出了通过收集火灾现场的有关资料对结构损伤进行判定的准则。并根据材料性质对损伤进行分类 ,提出了对于不同的损伤等级根据维修准则选择喷射混凝土、树脂维修、加覆层维修等不同的维修方法 ,通过维修可以保证结构的强度、稳定性。

In the present paper, the detailed technical specifications for structural fire protection in accordance with the construction laws and regulations are introduced. The methods of the field prove and tests of the fire damage structures are presented. At present, there are several kinds of techniques used to evaluate fire damage of the concrete structures, such as visual observations, core samples, impact rebound hammer and other complex methods such as pulse velocity/ultrasonic methods, petrographic analysis and load testing.The techniques typically applicable to the evaluation of fire damaged steel structures may include visual inspection of structural members,connectors,fasteners,welding pieces as well as the dimensional charges. The evaluation rule of the fire damage structures is determined by collecting the proof in the field. A damage classification method according to materials rather than structures is proposed and repair criteria and repair methods are summarized. The repair criteria may be inferred depending on material and structural parameters. An optimum repair method can subsequently be developed and applied for each individual case. For the convenience of practical use, flow charts of procedures should be established. The repair methods include sprayed concrete, resin repairs, propping, jacking and other techniques such as alternative supports, polymer modified mortars, cement mortars, plaster, sprayed mineral fibre, etc. The damage structures can be restored in the strength, fire resistance, durability, appearance by repair.