MVME236-3模塊卡件
持證設(shè)計專業(yè)人員應(yīng)根據(jù)ACI 437R、ACI 562、ACI 369R和其他適用的ACI文件對現(xiàn)有結(jié)構(gòu)進行徹底的現(xiàn)場調(diào)查?，F(xiàn)場調(diào)查應(yīng)至少確定以下內(nèi)容：a）結(jié)構(gòu)構(gòu)件的現(xiàn)有尺寸b）裂縫和剝落的位置、尺寸和原因c）現(xiàn)有鋼筋的數(shù)量和位置d）鋼筋的腐蝕位置和程度e）存在活性腐蝕f）混凝土的就地抗壓強度g）混凝土的堅固性，應(yīng)根據(jù)ASTM C1583/C1583M進行拉脫附著力試驗，以確定FRP系統(tǒng)可能安裝在混凝土上的表面上混凝土的抗拉強度。應(yīng)根據(jù)ACI 562要求使用芯材確定混凝土的現(xiàn)場抗壓強度。現(xiàn)有結(jié)構(gòu)的承載能力應(yīng)基于現(xiàn)場調(diào)查、設(shè)計計算和圖紙審查中收集的信息，并通過分析方法確定。如果認為合適，可將負載測試或其他方法納入整體評估過程。用于提高現(xiàn)有構(gòu)件強度的FRP系統(tǒng)應(yīng)根據(jù)第9章至第15章進行設(shè)計，其中包括對荷載限制、合理荷載路徑、溫度和環(huán)境對FRP系統(tǒng)的影響
荷載考慮以及鋼筋腐蝕對FRP系統(tǒng)完整性的影響的全面討論。1.2.1.1加固極限通常，為了防止FRP系統(tǒng)受損時構(gòu)件突然失效，施加加固極限，以限制用FRP系統(tǒng)加固的構(gòu)件承載能力的增加。其理念是，F(xiàn)RP鋼筋的損失不應(yīng)導(dǎo)致構(gòu)件失效。第9章提供了具體指南，包括評估FRP系統(tǒng)損失后構(gòu)件完整性的荷載組合。1.2.1.2防火和生命安全FRP加固結(jié)構(gòu)應(yīng)符合適用的建筑和防火規(guī)范。根據(jù)適用的建筑規(guī)范，根據(jù)建筑物的分類，安裝應(yīng)符合ASTM E84規(guī)定的煙霧產(chǎn)生和火焰蔓延等級。涂層（Apicella和Imbrogno 1999）和隔熱系統(tǒng)（Williams等人2006）可用于限制煙霧和火焰蔓延。由于大多數(shù)FRP材料在高溫下會退化，因此假設(shè)外部粘結(jié)FRP系統(tǒng)的強度在火災(zāi)中完全喪失，除非能夠證明FRP在火災(zāi)所需的持續(xù)時間內(nèi)仍然有效。通過使用某些樹脂、涂層、絕緣系統(tǒng)或其他防火方法，可以提高FRP加固混凝土構(gòu)件的耐火性（Bisby等人，2005b）。
Certified design professionals shall conduct a thorough site investigation of existing structures in accordance with ACI 437R, ACI 562, ACI 369R and other applicable ACI documents. The site investigation shall at least determine the following contents: a) the existing size of structural members b) the location, size and cause of cracks and spalling c) the number and location of existing reinforcement d) the location and extent of corrosion of reinforcement e) the presence of active corrosion f) the in-situ compressive strength of concrete g) the soundness of concrete, and the pull off adhesion test shall be conducted according to ASTM C1583/C1583M, To determine the tensile strength of the concrete on the surface on which the FRP system may be installed. The field compressive strength of concrete shall be determined using cores in accordance with ACI 562. The bearing capacity of the existing structure shall be based on the information collected in the field investigation, design calculation and drawing review, and shall be determined by analysis method. If deemed appropriate, load testing or other methods may be incorporated into the overall evaluation process. FRP systems used to improve the strength of existing members shall be designed in accordance with Chapters 9 to 15, including the effects on the FRP system of load limits, reasonable load paths, temperature and environment
A comprehensive discussion of load considerations and the effect of rebar corrosion on the integrity of FRP systems. 1.2.1.1 Reinforcement limit Generally, in order to prevent the member from suddenly failing when the FRP system is damaged, the reinforcement limit is imposed to limit the increase in the bearing capacity of the member strengthened with the FRP system. The idea is that the loss of FRP reinforcement should not lead to failure of the member. Chapter 9 provides specific guidance, including load combinations to assess the integrity of members after loss of the FRP system. 1.2.1.2 Fire and life safety FRP reinforced structures shall comply with applicable building and fire codes. The installation shall comply with the smoke generation and flame spread rating specified in ASTM E84 according to the applicable building code and the classification of the building. Coatings (Apicella and Imbrogno 1999) and thermal insulation systems (Williams et al. 2006) can be used to limit smoke and flame propagation. Since most FRP materials will deteriorate at high temperatures, it is assumed that the strength of the externally bonded FRP system will be completely lost in a fire unless it can be demonstrated that the FRP remains effective for the required duration of the fire. The fire resistance of FRP reinforced concrete members can be improved by using certain resins, coatings, insulation systems, or other fire protection methods (Bisby et al., 2005b).
